Slippery Slope and Perpetual Comeback

If a game has slippery slope, it means that falling behind causes you to fall even further behind.

For example, imagine that every time your team scored in basketball that the opponent’s team lost a player. In that game, falling behind is doubly bad because each basket counts for score AND it makes the opposing team less able to score points of its own. The actual game of basketball does not have this screwy feature though, so real basketball does not have slippery slope. Scoring in real basketball puts you closer to winning but does not at all hamper your opponents’ ability to score.

Slippery slope is another name for positive feedback, a loop that amplifies itself as in a nuclear reaction. Because people confuse the terms positive and negative feedback so easily, I prefer the more descriptive term slippery slope.

Slippery slope is usually a bad property in a game. If a game has a powerful slippery slope effect, that means that when one player gets a small early lead, he is more likely to get an even bigger lead, which in turn makes him more likely still to get yet an even bigger lead, and so on. In a game like this, the real victor of the game is decided early on, and the rest of the game is futile to play out (or to watch).

StarCraft and Chess do have slippery slope. They manage to be good games anyway, despite this anti-climactic property. In Chess, when a player loses a piece, his ability to attack, defend, and control space on the board is slightly reduced. Sure, there are many other factors in Chess--positioning, momentum, pawn structure--that determine if a player is actually “losing,” but losing a piece does have an effect. Clearly, losing a lot of pieces, say 8, puts a player at a significant disadvantage. It’s pretty hard to make a comeback in Chess, and a game is usually “won” many, many moves before the actual checkmate move.

This is why there are a lot of forfeits in Chess. Good players don’t actually play out the pointless part of the endgame when they recognize the opponent will definitely win. Chess players would say that forfeits being a regular part of the game is fine and not awkward, but it’s a disappointing quality compared to games without slippery slope. Still, Chess is a pretty good game anyway.

This guy just lost a Chess piece.

StarCraft also has slippery slope. When you lose a unit, you are penalized doubly. First, you are closer to losing (having no units at all is so crippling as to be virtually the same as the actual loss condition of losing all your buildings). Second, you are less able to attack and defend because the unit you lost was not just part of a score, but also part of the actual gameplay of attacking and defending.

In basketball, the score is completely separate from the gameplay. Your ability to score points doesn’t depend at all on what the current score is. You could be ahead by 20 points or behind by 20 points and have the same chances of scoring more points. But in StarCraft (and Chess), the score is bound up with the gameplay. Losing units pushes you closer to loss AND makes it harder to fight back.

StarCraft has even more severe slippery slope when it comes to the game’s economy. Imagine that your opponent rushes you (sends an early attack to your base) and you fend it off. Let’s say you each lost about the same value of units in the exchange, except that you also lost one worker unit. In a different type of game, this might equate to being one “point” behind. But in StarCraft, that can be a crippling loss because gathering minerals is nearly exponential. Your opponent is ahead of you in the resource curve, increasing his earnings faster than you are. You’ve fallen down a very slippery slope here, where an early disadvantage becomes more magnified as the game goes on.

Fighting Games

Fighting games don’t usually have slippery slope. In Street Fighter, for example, your character still has all of his moves even when he’s about to lose. Getting hit puts you behind in life totals (in “score”) but doesn’t limit your gameplay options in the way that losing a piece in Chess does or losing a unit in StarCraft does. An unusual example of a fighting game that does have slippery slope is Bushido Blade. In that game, getting hit can cause you limp around or lose the use of an arm. This is extremely rare in the fighting game genre though, and for good reason.

While it might be "realistic" for a nearly dead character to limp, move slowly, and have generally less effective moves, it's not fun. (At least in Bushido Blade's case, this part of the game lasts only a couple seconds, then you lose.) Meanwhile in Street Fighter, comebacks are frequent and games are often "anybody's game" until the last moment. Street Fighter does have some very minimal slippery slope aspects (if you're very near death you have to worry about taking damage from blocked moves which aren't a threat if you have full life), but overall it's pretty "slippery slope neutral."

There is one fighting game that stands out as an exception: Marvel vs. Capcom 2. In this game, each player chooses 3 characters. At any given time, one character is active and on-screen, and the other two are off-screen, healing back some lost energy. The off-screen characters can be called in to do an assist move, then the jump off screen again. The main character can attack in parallel with the assist character, allowing for a wide variety of tricks and traps. The player can switch the active character at any time, and he loses the game when he loses all three characters. But here, slippery slope rears its bitter head. When one player is down to his last character and the other player has two or even all three of his characters, the first player is at a huge disadvantage. The first player has can no longer attack in parallel with his assists, which often means he has no hope of winning. Comebacks in MvC2 are quite rare and games often "end" before they are technically over.

Fighting games with "ring out" such as Virtua Fighter and Soul Calibur as especially devoid of slippery slope properties. In these games, a player instantly loses if his character is ever pushed out of the ring, no matter how much energy he has. Basically, no matter how far behind you are, no matter how close you are to losing, you always have a 100% damage move: ring out. Long ago, I thought this concept was "cheap" and served only to shorten games while adding little benefit, but actually the threat of ring out adds quite a bit to both these games. Since the threat of ring out is so great, another whole element of positioning is added to the game. A player must fight both to do damage to his opponent, and fight for position to avoid ring out.

Limited Slippery Slope

Fighting games do have very localized, limited kind of slippery slope that’s actually a good quality. If a game truly has no slippery slope whatsoever at any point, then it can feel like a series of disconnected decisions. It’s interesting though, if a decision you make at one point in a game echoes forward through time, and can influence later moves in the game. The problem is if this influence is allowed to snowball into a greater and greater advantage.

In limited slippery slope, there is a cap on how far you can slip and the effect is temporary. In Street Fighter, getting knocked down (hit by a sweep) does have a bit of slippery slope. You lose health (“score”) but you also have temporary limitations on what your character can do. Your character falls down, then gets up into what is usually a disadvantageous situation. The two things that are important about this are: 1) after the knockdown is over, you regain all your moves and 2) you cannot get doubly knocked down.

Ken is at a temporary disadvantage here from being knocked down, but the disadvantage can't snowball into deeper levels of knockdown (there aren't any) and it fades with time.

Hitting the opponent with a sweep does echo forward through time, but this advantage is reset soon after and can’t snowball into “getting REALLY knocked down” because there is no such thing as degrees of knockdown. If you are already knocked down, you can't be knocked down "even more."

Another example is backing the opponent into the corner (the edge of the stage). If you do this, you have a natural advantage because the opponent has fewer movement options. But again, there’s a limit here. Once the opponent is in the corner, he can’t be “more in the corner.” There’s a limit to how disadvantaged he can get.

An even more basic example is anytime you block a move that has a fair amount of recovery. In these case, you recover from your blockstun before the opponent recovers from his move, so you have a few frames to act first. This gives you an advantage because if you both try to do a move of the same speed, yours will win (it will start first). Your good decision to block echoed forward into the future, but the effect is very fleeting. Even one second later, this advantage fades.

So fighting games are full of small, temporary slippery slope effects that actually help the game. And yet, on the macro level, they do not have the real kind of slippery slope, the permanent kind that snowballs until the game ends. Compare this to Chess where you don’t just get your captured pieces back a few turns later.

And RTS Without Slippery Slope

Here’s an idea for turning the full-on slippery slope (usually bad) into the limited kind (usually good). Both players start with the same amount of resources to buy units. When your units are destroyed, your resources are refunded. A delay in the timing of this refund combined with the build-time for making new units means that losing units really is a disadvantage, but that the disadvantage fades over time, similar in nature to getting knocked down in a fighting game. The real-time strategy game World in Conflict does exactly this, but I’ve never actually played it.

My point here isn't about whether World in Conflict is a good game, or even whether the exact refund system stated above is good. It just shows that it is possible to remove slippery slope from an RTS if you try hard enough. Someone very dedicated to that problem could probably come up with an even better way to remove it that results in a deeper game, rather than a shallower one.

Perpetual Comeback

The opposite of slippery slope, I call perpetual comeback. That’s just a more descriptive term for negative feedback. (Also, negative feedback sounds like a bad thing, but it’s usually a good quality in games, so it’s helpful to have a term that doesn’t sound negative.) A thermostat uses negative feedback to keep the temperature of a room from spiraling out of control.

Perpetual comeback, then, is a quality in which being behind actually gives you an advantage. I’d like to draw a distinction between two types of this effect, though. In one, when you are behind, a force pushes on you to help improve your position. An example of this is the Fatboy mutator in Unreal Tournament. In that first-person shooter mod, when you kill an enemy, you become fatter and easier to hit. When you die, you become skinnier and harder to hit. Multiple hits magnify the effect, so if you die over and over you get skinner and skinner. Note that even if you die a lot, you are still losing (your score is not helped), but you do have an advantage (harder to hit).

Beautiful, but dangerous.

A similar example is any version of Mario Kart. The further behind you are, the more powerful the items you get. In last place, you can get the powerful blue turtle shell which has homing powers to zero in on the first place racer. Meanwhile, the first place racer gets only weak items.

Advance Wars: Dual Strike on the Nintendo DS has a similar feature. Each side has a powerful “tag attack” that’s tied to a meter. When you get attacked, your meter fills up at twice the rate as usual, so the losing player will have faster access to this powerful attack, giving him a chance to make a comeback.

In all three of these examples, the games have a force that help out players who are behind and hinder players who are ahead. This is generally a good type of force to have, because it makes games closer, and small early mistakes are not crippling. That said, maybe the effect is too extreme in Mario Kart, or maybe it creates strange artifacts such as avoiding 1st place on purpose for most of the race. And the power of the tag attacks in Advance Wars might be too extreme, making them dominate the game. Tuning issues aside, the concept is still sound and when it’s done right, it can make matches closer and more exciting.

Perpetual Comeback Extreme

There is a different type of perpetual comeback that is far more extreme and far more rare. That’s when getting closer to losing doesn’t JUST give you helping hand, but instead actually puts you ahead. I think the best example of this strange property is Puzzle Fighter.

Puzzle Fighter is, in my opinion, the best puzzle game ever made and I felt that way long before I was lead designer of Puzzle Fighter HD Remix. The game seems standard enough--it's one of those games where each player has a basin that pieces fall into. There are four different colors of pieces, and you try to build big, single colored rectangles (power gems). You can then shatter those rectangles with special pieces called crash gems. The more you break, the more junk you drop on the opponent's side. When your side fills to the top, you lose.

Several factors come together to create perpetual comeback (the extreme version!) in Puzzle Fighter. Firstly, each "character" (there 11 to choose from, including secret characters) has a different "drop pattern." A drop pattern is the pattern of colored blocks that a character will send to his enemy when that character shatters blocks on his own side. For example, Ken's drop pattern is horizontal row of red, followed by a horizontal row of green, then yellow, then blue. Every time Ken sends 6 or fewer blocks to his opponent, he'll send a horizontal row of red. Every time Ken sends 12 blocks, he'll send a row of red, then a row of yellow. Since the enemy knows this, he can plan for it. He can build his blocks such that Ken's attack will actually help rather than hurt. There's one catch: when you send blocks to the opponent, they appear in the form of "counter gems," which can't be broken immediately by normal means, and can't be incorporated into deadly power gems. After about 5 moves, the counter gems change into regular gems.

The other very critical property is that power gems broken higher up on the screen do more much more damage (send many more counter gems) than gems broken at the bottom of the screen. So consider what attacking is actually like in this game. Attacks are really only temporarily damaging, until the counter gems turn into regular gems. At that point, the opponent will probably be able to incorporate the gems into their own plans, since the opponent knows your drop pattern. Even if the opponent isn't able to benefit from your attack in that way, he can still "dig himself out" of trouble by breaking all the stuff you sent him. By filling up his screen most of the way you've basically given him more potential ammunition to fire at you. What's more, as he is nearest to death, his attacks will be the most damaging due to the height bonus. Gems broken at the very top of the screen do significant damage.

Puzzle Fighter has the extremely unusual property that "almost losing" looks exactly like "almost winning." Let's say you break a whole slew of power gems and send a large attack at your opponent. You're screen is now almost empty. You're winning right? His screen is nearly to the top--almost full. He's losing, right? Well, he is on the verge of losing, but he has all the ammunition and he has the height bonus, whereas you have almost nothing left to defend with. In effect, your opponent is both "losing" and "winning" at the same time. Very curious, indeed!

Ken (left) was close to losing, but he got the yellow crash gem he needed just in time. Donovan (right) will lose.

It turns out the best way to play Puzzle Fighter is to very carefully never attack until you can make it count. All those little jabs you make just help the opponent in the long run. You've got to save up for a huge, 1-2 punch. You need to send a big attack that almost kills them, then immediately send another attack that finishes them off. 1, 2! The point is that Puzzle Fighter is a high energy, edge-of-your seat game. Your opponent very often has enough attack to kill you, so you have to have enough defense to stop them. Whenever the scales start to tip in your opponent's favor, they have also, weirdly, tipped in your favor as well, in some sense. A game of Puzzle Fighter is never over until the last moment. Comebacks are the name of the game, and the excitement goes to the very last second almost every time.

Conclusion

Slippery slope is a force that punishes players who fall behind, making them even more likely to fall further behind. Left unchecked, this makes for matches where the real victor is decided long before the game actually ends, leading to either boring endgame play, or lots of forfeits. While fighting games lack this overall slippery slope, they do have several forms of temporary, limited slippery slope that improves gameplay. This limited slippery slope probably exists in other genres as well, but could be a conscious design choice for future games. Finally, perpetual comeback, the opposite of slippery slope, is a force that helps losing players and puts the brakes on winning players, making for close matches. This property can easily go wrong if tuned improperly, but if done well, it leads to closer, more exciting matches. Puzzle Fighter takes this concept to an extreme, by making winning look almost the same as losing.

Comments

[Brutha]

Battle Realms is a RTS game where you can produce new units faster if your units have died and therefore have a kind of perpetual comeback.

In general slippery slope is about the ability to make strategic decisions that matter. If there is no possibility to get into a strategic advantage that will increase your chances of winning in the rest of the game your game has only tactical choices and you don't need the long term thinking that characterizes a strategy game.
Therefore those games that require a lot of strategic thought like chess or go often end through one party forfeiting because they lost all chances to win the game.
In some kind of technical sense nearly every go game ends with forfeit as the two players both agree on the result and the result doesn't come directly from the board (if both players think that a certain group is alive it's alive, even if it would be possible to kill it).

Slippery slope only becomes a problem in game design if there is still something like a 2% chance to win the game for a long time after the game got decided. In that case people won't resign and there is a boring endgame.

[InTheory]

Levi said: "Sirlin's examples are pretty well chosen and provide a good idea of how these forces affect a game. While all the games mentioned have some mix of feedback types, they also tend to be dominated by the type of feedback they've been chosen to illustrate. Various styles of games have a dominate feedback style that is normal for them and the examples illustrate this pretty well."

Alright, Levi, I can see where you're coming from when you say that games have a "mix of feedback types". However, I strongly disagree with your statement that "they tend to be dominated by the type of feedback they've been chosen to illustrate." Keep in mind that in this case, it was Sirlin doing the choosing, and he hand-picked examples from each game to suit his own argument, much like a politician will rig a speech with examples that support his particular opinion. Check this out: there are games of SF that are horribly brutal because one character manages to combo another character literally to death, starting with just one hit. To put it another way, both players start at 100% health, and then one player takes a hit and has, say, 95% health left. If the player who delivered the hit manages to score a combo, the player who just got hit will lose even more hitpoints. Combos are inherent examples of "more-than-neutral" slope in SF, and certain combos can be "0-to-death", meaning that one hit = death for the player being hit. Combos aren't always this brutal, but they can be, just like situations in StarCraft can end the game in one battle, or go back and forth between both players. True, StarCraft does allow for horribly "slippery" situations to occur, but that doesn't mean that every game is "dominated" by slippery slope. Many games go back and forth with multiple climax points before a victor is determined; other games end in a few minutes when one player makes a stupid mistake. Either way, it's ridiculous to imply that StarCraft is "dominated" by slippery slope, because there are many games where you don't even see the effects of slippery slope. Just the same it's ridiculous to say that SF is "dominated" by purely neutral slope because there are some games where one player is put in situations where one mistake = death (a 0-to-death combo being just one example of this...trap situations are even worse).

Levi also said: "The particular example of the Honda corner trap is quite silly. It's not a feedback loop of any kind. No matter how little life you have, your chance (even if, as claimed, it's zero) does not decrease. Nor does it decrease the longer you've been trapped. (Unless the stress gets to you.) It's an abusable design flaw, but that doesn't alter the fundamental character of the game, especially in regards to feedback loops. Furthermore, it was fixed in the rebalanced mode of HD Remix, which Sirlin himself was in charge of."

The example is silly? I don't care what you call it - it's a brutal situation for the trapped player that definitely exemplifies "more-than-neutral" slope. Previous posters in this discussion have already stated that trap situations are almost impossible to get out of, and very hard on the trapped player. I don't think you can dispute that, especially since it contradicts your "100% health" example quite nicely - getting stuck in a trap situation like this will definitely decrease your chances of winning the game more than other "normal" mistakes would. I repeat, not all SF games are like this, but it's a factor that must be considered. This is why generalizing and hand-picking examples to represent what you WANT to see in games over what's actually IN them is not such a good idea. It's extremely difficult to pick one or two examples that fully explain a game, especially in regards to what types of competitive slope they have.

And, if Sirlin did choose to remove this "design flaw" in the later game, well, I guess that says that it was probably too close to a "slippery slope" element for his comfort. Not surprising.

[Hurkyl]

InTheory: I think one of the points you're missing is that "slope" is not a measure of advantage/disadvantage. Slope has nothing to do with how weak/strong a particular attack is, or how advantageous/disadvantageous a particular situation is.

The E-Honda vs. Bison trap is not a slippery slope because you cannot get "more trapped": you sit at exactly one level of trapped-ness. The fact the trap is effectively inescapable is completely irrelevant to the judgement of how the situation is sloped.

[Fitzy]

Reading this article and the ensuing snarky debates has spawned all sorts of questions in my mind. Foremost, is there any game that involves resource management that does NOT suffer from Sirlin's slippery slope?

Out of the games already mentioned, the only one I'd consider myself really competitive in is Magic: the Gathering, and while I instinctively know that yes it does have such a slope, I'm having a hard time quantifying it. The scorekeeping mechanism, life totals, is not mechanically relevant (unless of course it is, thanks to a card like Necropotence or Hatred or Char-- part of what makes Magic so difficult to discuss in theoretical terms) and in terms of comeback potential, life totals generally don't mean anything: Dragonstorm and Replenish are just two examples out of many historically dominant constructed archetypes that somewhat famously don't attack the opponent at all until they win the game on One Big Turn. At the same time, to say that life totals don't matter with these archetypes is to ignore a lot of their tactical complexity, since a big part of winning strategy against combo decks involves applying pressure so that the combo player must attempt to go off before he/she is comfortable. Even in something like a sealed deck game, there will be situations in which a player's low life total forces him to make unfavorable blocks to avoid lethal damage.

Incremental advantage is much more evident when looking at card advantage, tempo, and board position. Pure card advantage is obviously incremental because it increases your odds of drawing additional pure card advantage (ex. playing Fact or Fiction and revealing a 2nd copy of Fact or Fiction), so that the player who gets ahead has an easier and easier time staying ahead. That may or may not be the same thing as a slippery slope. Tempo is a little murkier. If I get hit with a turn 3 Stone Rain, then the lost land will mean I have one fewer mana to spend each turn for the rest of the game than I would have had, which is probably the closest direct parallel to losing an early RTS gatherer or Chess pawn. The catch is, while the Stone Rain is ostensibly a 1-for-1 trade (your Stone Rain for my land) I have many more lands in my deck and unless the game ends quickly I will surely draw more land than I actually need. This means that one of my later draws that would have been dead (the first extraneous land I would have drawn) is now useful. It also means that If you draw another Stone Rain fifteen turns later when we both have extraneous lands in play, it is virtually a blank card. Stone Rain, therefore, can be considered a gambit: you put it in your deck hoping that the temporary board advantage it buys you will allow you to win before the card disadvantage actually matters. This play is almost identical to, say, sacrificing a pawn to gain a tactical advantage, or sending a unit to the enemy base (where it will surely die) to gain information and a slight tempo advantage when your opponent must divert his attention to deal with it.

The point of all that is that slippery slopes certainly exist in Magic, but its a different kind of slope every game. In a control mirror the conventional wisdom is that the first player to miss a land drop is at a disadvantage, but in most aggro mirrors, the exact opposite is true: both players need a certain number of lands to function, and past that point want nothing but business spells. If your opponent is still playing real threats while you are glumly plunking down land #9 and saying go, you will almost certainly lose.

Back to Starcraft: I would suggest that, much like the "slippery slope" created by Magic's turn 3 Stone Rain, an early resource loss in these usually represents a gain made in another area. I realize, Sirlin, that your definition of a slippery slope takes these factors into account and is meant to be applied only to situations in which a player (usually as a result of his own mistake) is at a distinct and unmitigated disadvantage. Some SC players have come out of the woodworks to defend their "pet game" from the charge that it is "flawed" because these circumstances can arise. The defense, I think, is that (a) these circumstances are, at the highest level of competition, far less common than you think, and (b) because Starcraft is played in real time and with limited information, it should be nearly impossible to positively identify such a circumstance. At a glance this refutes nothing: the slippery slope is still there sometimes, even if we can't always see it. The game could only be considered "flawed", at least in my opinion, if the existence of such a slope negatively impacted the gameplay experience in a meaningful way. And of course, for some it does, but this is a matter of taste. To suggest that a game is flawed for this reason is to imply that there is otherwise some state of flawlessness that it could achieve, which is a different debate entirely.

To return to my original question, resource management games (or, perhaps too broadly, any game in which the available options at a given moment are dependent on actions taken at previous moments) cannot, as far as I can fathom, be made without having a slippery slope in some form.

A final note on the previously mentioned football game that is 49-0 at halftime: There IS a slippery slope involved here. It isn't quantifiable using the game's mechanics, but a comeback from that situation will simply never happen. The team with the lead will, on offense, make extensive use of running plays to keep the clock going and, on defense, bolster its secondary to help prevent big passing plays. I'd be willing to bet that data exists to demonstrate that the further behind a football team falls, the fewer points it will score before the game is over, and not just because of intangibles like morale.

[Melf_Himself]

In general, I'd say a slippery slope exists when your actions at a given point of the game affect your options at later points in the game.

In games like soccer or basketball, after a score is awarded the capabilities of both sides are reset, so that they have the same number of options as before the score was awarded.

In between these scoring occasions though, slippery slope exists. In basketball, if you've got the ball down your end of the court, your odds to score the next basket are dramatically increased, and the odds of the other team scoring the next basket are dramatically decreased. In soccer the same applies, however the odds were very small to begin with, making it a low scoring game ;)

In SF this applies as well - after a particular exchange, a score (damage) is awarded, and then both parties return to the capabilities they had before the exchange. There is some exception to this (low HP and block damage).

In Starcraft the capabilities of both sides are reset only between matches. The only 'score' is a binary one, whether you're the last (wo)man standing or not. All the actions occurring up to that point alter your odds of being the one to score that solitary point. This means that I can make 10 minor sound plays and accrue a small advantage, increasing my odds to win moderately, and this can be undone by you executing a move with a payoff greater than all my minor plays, to give yourself the advantage to score the next point. This is similar to a situation in basketball where the ball is stolen from someone dribbling in the key, and passed quickly to a running team mate down the court.

The only difference in Starcraft is that there is only one basket/score to be made per game. The whole discussion would become moot if each match of Starcraft was decided by the outcome of, say, 100 individual games, as the capabilities of both sides would obviously be reset in between those matches. This would give the gave minimal slippery slope in the global sense.

So, it would be possible to design a strategy game, even an RTS, that does not have slippery slope in the global sense - you'd just have to reset the player's positions periodically, and keep tab of the score that they accrued in between resets. Whether this would be fun or would fit conceptually to the whole military idea is another matter...

[sadpandabear]

"For example, imagine that every time your team scored in basketball that the opponent’s team lost a player. In that game, falling behind is doubly bad because each basket counts for score AND it makes the opposing team less able to score points of its own. The actual game of basketball does not have this screwy feature though, so real basketball does not have slippery slope. Scoring in real basketball puts you closer to winning but does not at all hamper your opponents’ ability to score."

This is untrue for basketball because there is a limited time to score. When an opponent scores a basket, it not only increases their own score, but also reduces the amount of time left for you to score a basket. While this type of slippery slope is very limited, it is a slippery slope nonetheless. Specifically, this becomes magnified late in a game where "daggers" can put a game out of reach, not just because of the points added but because of the fact that the time remaining is not enough to score an adequate number of points to win. The same applies to fighting games. Late in a round, if an opponent has a slight advantage in life and scores an attack against you, not only do you lose some life, but you also lose precious time to make up the difference since generally you are at a frame disadvantage after being hit.

Edited by Sirlin: I think you chose to intentionally miss the point here in order to nitpick.

[Auspice]

Wow, I see InTheory trolled this thread up for months.

I don't know how he can still be citing the Honda example of the corner trap. If you get stuck in the corner against Honda or Zangief or THawk or whatever, it is a very bad situation and it is very hard to get out. However, that situation isn't actually slippery slope. Getting hit by Honda in any way except a way that knocks you down in the corner does not put you closer to getting trapped, generally speaking. Eating a Honda jumping short or something does absolutely nothing except take some life off and give Honda some frame advantage. If Honda doesn't take that advantage immediately and convert it into more tempo advantage, his opponent can footsie or reversal out and Honda is back in a neutral or bad situation. This is not slippery slope. Getting hit by 3 oicho throws in the corner does not make it any harder to escape Honda's oicho loop. It is hard to escape the oicho loop but immediately after doing so, the situation is either neutral or bad for Honda, regardless of Honda's or his opponent's remaining health.

Also worth noting is that ST is a flawed game. Not flawed in the sense that it is a bad game, but it certainly has flaws. HDR has fewer flaws, to be sure, but even HDR has some flaws. Even the design of SF has some important flaws, such as unnecessary dexterity tests and situations where one player has one clear best choice. It's okay to admit that SF has some flaws both in the individual games and as a series. The key distinction that we can make is that SF is still a great game in spite of these flaws.

SC is much the same way. It's a flawed game. I don't think anyone with any sort of understanding of game design can refute this. If you can't admit that SC has flaws, you are very biased and shouldn't be posting on this topic. As of yet, there is no 'perfect' game which embodies everything everyone wants or even what a select group of people want in a game. Even the best SC players in Korea could probably explain a few ways in which the game could be improved. Most likely, they would not agree, either.

In spite of all this, Starcraft is an amazing game. It's very well-made and has a lot of great game dynamics. That's somewhat of an opinion, but I think that if you do not agree with it, you probably have poor taste in games, haha.

[sadpandabear]

I wasn't really nitpicking, i was making a point that I didn't see addressed in your article at all. The idea of time as a resource that you lose in addition to your life points/score total/whatever was something that I thought of while reading your article and decided to mention since I had not seen it brought up in any of the comments. This being said, I think that any game with a limited amount of time suffers from a slippery slope (albeit, this slope is often hard to notice until time is close to expiring) In football for example, although a field goal is worth only 3 points, the scoring of those 3 points may take the entire fourth quarter and thus make the other team unable to score. Likewise in basketball, if a team takes 24 seconds to put 2 points on the basket, that's 24 seconds less that you have to score. Does this type of temporal slippery slope make for a worse game? In most cases, probably not. For one, it's hardly feasible in sports as you have an additional factor of athlete fatigue. As a game gets longer, one team would likely become more affected by this factor due to age, prior injuries, illness, and other things. Secondly, for fighting games it would often result in situations where both players optimal strategy is to turtle. However, adding a temporal slippery slope to games that don't already have it may be a bad idea. The main issue with this would be to implement a time restraint that allows for comebacks to occur late into the game as well as one that does not have a steep slippery slope until late into the game. However, sometimes it is unavoidable to have such a time limit due to concerns outside of the game. Magic: The Gathering for example, has time limits per round. This often allows decks that are able to win very slowly before people are able to sideboard against them to be very powerful in tournaments. However, if that exact deck played 3 full games against a player including sideboard they might lose. What ends up happening is the "worse deck" ends up winning because it is able to win that first game. Conversely though, if that deck loses the first game, it ends up being an uphill battle against time since the deck neither wins nor loses quickly.

This is just some of the things that your article provoked me into thinking. Do you think there is a general answer as to whether time-restraint is better or worse? Or do you think is it dependent on the game at hand?

[Auspice]

Although Sirlin is probably busy in the SF4 topic, I can address the time constraints too!

I think it is almost universally a good mechanic. The reason why in pro sports the time mechanic is less fun is because there isn't a target score. In SF, when you score enough, you win. Same for M:TG actually. Even though there are time functions in those games, the time feature is mostly there to prevent lengthy stalls and provoke the losing player into attempting to win instead of minimzing further loss. As an example, I played in a SC3 (soul calibur, not starcraft) tournament where the timer was disabled, so I played constant turtle and safe poked my way to wins, playing a strong defensive game. If we don't incorporate a timer, the entire game sort of degenerates because people will want to play as safely as possible and minimize risk unless the payoff is huge. Because there are timers we are encouraged to attack because the amount of time we have to win a match is limited, and unless we get a substantial lead near the end, we want to press the advantage and not let the opponent turn the match around.

In starcraft, time is definitely a resource because if X amount of time passes you generate Y minerals for every worker you have, and you can only have so many workers mining at once. So basically in SC time is a resource that gets converted into every other resource, whether it be minerals, gas, or attention - because obviously if I have 100 APM (hypothetical number, my APM is probably closer to 50 haha), I basically have 100 things I can do each minute - obviously that will spike up and down but it evens out more or less over the course of the game. And of course the game is basically whether you can deal greater than X*Y of your opponent's resources during conflicts while preventing them from doing the same to you - obviously this is really simplified because obviously you can do lots of damage by evading enemy defenses in sneaky ways, disrupting their flow of minerals, etc. etc. but that's basically SC in a nutshell - gain a large enough economic lead that it's GG and your opponent forfeits.

[Thisorder]

Just goint to throw this in here:
I may be wrong but the way you write seem to imply to that chess is played on the board itself, which isn't how it's played at all. Chess is played in the "abstract space" which the pieces and board repressent/creates, and that is where a loss/win is determined.
There is no difference at all between taking a piece or taking position, etc. every move is meant to do the same thing, cutting of part parts of that abstract space until all that remains is yours and then then the game is over. If there are 1 move or 30 moves left until a checkmate on the PHYSICAL BOARD at that point is irrelevant, since that's where the game is played.

Actually after thinking about it, this probably goes for the strategic elements in any game.

This blogg is seriously great, btw. I feel myself getting smarter even when by disagreeing with you.
= )

Response by Sirlin: Starcraft is not played on a computer, but actually in the biological substrate of the brain. Therefore, when you strike a crippling blow against the enemy that will definitely lead you win, but the game isn't actually over yet, "it's irrelevant since the game isn't played on the computer." That argument makes just as little sense as yours. Regardless of "where the game is played," in each case the win condition of the game doesn't line up very well with when the winning move is made. The unfortunate lag time between the two events is not somehow removed by trying to define that the game takes place in your head.

[SparroHawc]

My god. In the nitpicking of individual games, you people have ALL missed the point COMPLETELY. The fact that Starcraft has survived as long as it has more-or-less proves that it isn't ruled by the Slippery Slope. Yes, it is a factor, because the worse you're doing the harder it is to get back on your feet due to the lack of resources to do so. But it doesn't rule the game; if it did, games would be decided in the first minute or two and that would be it. The Zerg/Zerg example proves this point.

But even I digress.

The point is, it's not fun to have a huge portion of game that is already decided and impossible to recover from, and it's (usually) not fun to play a game where if you're doing well for the first half of the game, the rest of the game becomes ridiculously easy. The second half of the game simply becomes a dull chore, and the thrill of the risk of losing/panic of trying to claw back into a winning position is completely gone. THIS IS PRIMARILY A PROBLEM WITH POORLY DESIGNED GAMES. The issue at hand is that if the author chose poorly designed games as examples, very few people would know about them because no one plays them. By selecting specific scenarios from well-known games, he was able to demonstrate his points in generally easily-recognized fashions. There were some generalizations made, yes, but frothing at the mouth about how this-game or that-game wasn't a complete representation of the example is pointless except to feed your rabid fanboy egos. It was an illustration, not a condemnation of the game, and for that matter, it was an illustration taken from one specific aspect of the game.

[Thisorder]

"Starcraft is not played on a computer, but actually in the biological substrate of the brain. "

REALITY is played in the biological substrate of the brain (even the perception of there being a biological substrate in the first place). However that and abstract space in chess is different things. Unless the starcraft players have a monitor giving them direct access to eachother brain activity or actual thought processes during play.
In either case, in any game where it's possible to read several possible moves ahead a match will be over before the actual "checkmate", you can't have one without the other. This is a feature, not a flaw.
Even in games which aren't decided before the last move matches are often over strategically before that point and the rest is down to mechanical skill, mindreading or luck.

Response by Sirlin: Uh what? Some games have a lame duck period where the winner is decided but the game drags on. These games require players to forfeit (and let's hope the loser does, rather than annoy you by dragging the game out.) Other games don't have that property. All the ridiculous claims about games taking place in your head or in biological substrates don't change that simple statement. It's not that all games are in the same category here. There really, truly are differences. Starcraft really is different than Street Fighter, in this one respect. One game ends when it ends (or occasionally it "ends" like 1 second before it ends). The other can end like 20 minutes before it ends. That really, truly is a difference that you can't define away with fancy philosophy. I guess you can define it away, but this serves no useful purpose.

As I stated in the article, all things being equal, you should try to avoid this flaw if possible. That much should be obvious. Why would you intentionally include the very annoying feature that opponents can drag a game out? The answer is that you would include that if it was outweighed by other properties of the game. That is the case with Chess with Starcraft. They are not automatically bad because they have this property. And yet it's still valid to say that you should avoid designing it if you have the chance to avoid it. I consider that very non-controversial, so it seems like you are looking to pick a fight for the sake of it.

[Thisorder]

While I generally agree draging the game on should be avoided if possible, you still miss my point.
In any game where players read ahead the game will always be decided at some point before the actual victory condition. If two good chess players know every possible move and countermove 15 turns ahead, the game will be over 15 turns before actual checkmate, at which point one of the players forfeit.
You can't have the "read ahead" feature without having players lose before what is technically the last move. The later is a direct result of the former.
This is what I meant all along, I used the mathematical concept of abstract spaces since it's decently describes how chessplayers actually think during gameplay. I assumed you were familliar with the it since it certainly seems that way from other stuff you write.

I'm not trying to pick a fight at all, as I said in my first post I really like this blogg. We just seem to have very different ideas about what strategy is, which in itself makes for an interesting discussion in my opinion.

Response by Sirlin: I maintain that I do in fact "get it" and that you are the one who doesn't. No matter how you slice it, some games end when they end. There is no 2 minute long futile portion of Street Fighter where the game is decided but the match isn't over. There really, truly is not. There *is* such a situation in Marvel vs. Capcom 2 though. Being down to one character when the other guy has 2 or 3 is usually a "might as well forfeit" situation. In that situation, playing it out is very boring. Forfeting is anti-climactic and bad too. Use all the concepts and terms you want, but those two games are of a different nature because of that. There IS a difference.

And all things being equal, you'd want to remove the bad lame-duck endings if you can. If you can't, then so be it. Other virtues of the game could make up for it. This should not be controversial, it should be obvious. Lame-duck endings are bad for spectators, boring, put the climax somewhere other than the end which makes it hard for new players and spectators to even know when the actual end really is. All bad and if you could remove that and still have a good game, you WOULD. If you want to argue you can't remove it from chess, you might be right, I never made any such claim about that.

[WF]

I recently started playing an online version of the classic boardgame Risk, and I was glad to have this article around so I knew how to articulate exactly what I hate most about Risk. It's the slippery slope factor.

When you lose territory, you don't just lose what armies you currently have, you lose the extra armies you'd be granted during your next turn. Meanwhile, the opponent who is in the lead holds MORE territories and gets MORE extra armies, and is also more likely to capture entire continents, which in turn grants even more bonuses. Once a player in Risk starts to fall behind, the gap between loser and winner grows at an ever-accelerating pace.

A form of Comeback ALMOST appears in Risk in the form of the cards. When you get a set of cards you can trade them in for more armies. But it doesn't quite work out in the losers' benefit, because all the players get cards, and each time cards are traded in, the number of bonus armies increases. So after a losing player desperately trades in cards to get an extra four armies, the winning player can go ahead and trade his cards in for six.

Plus, you only get cards by capturing territories, and if you're losing badly enough, you simply won't have enough armies to attack another player. No capture, no cards, no comeback.

The only saving grace in Risk is the randomness involved in the form of dice rolls. It's possible for a winning player to have really bad luck on one turn, and lose a large number of armies on some ill-fated assault. A losing player may then be able to take advantage of that and mount a comeback, but that doesn't seem to happen very often.

So I know this article is an old one, but I wanted to throw out Risk and its online versions as a prime example of a game with far too much slippery slope.

[Threadnaught]

*sigh* Imagine a Strategy game without a Slippery Slope...

Advance Wars Dual Strike, powers off, funds set to maximum and a symettrical map with both players spamming Megatanks until one player Yields.

Having played Chess, Command and Conquer, Age of Empires, Advance Wars, Star Wars: Empire at War and a pair of non Strategy game examples of Star Wars Battlefront and Left 4 Dead.

These are all games where the theme is to have a group or team of units working together, they have to work together to use each unit's strengths and take advantage of an enemy unit's weaknesses, losing one unit should never be a bad thing, if you put all your planning, hope and strategy on the back of a single unit, losing that is the ultimate slippery slope which causes a low level player to lose the game.

Okay Star Wars: Empire at War Online, I can count my losses on one hand, having played nearly 50 matches before everyone stopped playing. I'd either quickly build a few fighters and rush my opponents crippling their space stations, or I'd just upgrade to level 5 and spam capital ships. Eitherway if I lost any of my ships I always had something ready to replace it. Because I always rushed to get to their space station first, their stations would take damage, this damage lowered their ability to fight me off, my reward for taking the initiative. I remember losing one time against two humans while my partner was an AI, they managed to get to my station first and I had to defend, if I had managed to intercept them and cripple their ships, maybe I could have won, but instead I struggled in a futile attempt to force them away from my station.

The ultimate example of slippery slope I saw while playing this game, one custom map I played had a lot of mines around so every player could get a massive amount of funds, but (this also slips into playing to win territory) we all experienced some horrible lag. During this lag I was able to take posession of almost half of the mines and my resource count had ended up rocketing as soon as the lag cleared up, I pulled off a horribly cheap technique and had been called out on it during the rest of the match and in the lobby. My team won partially due to my massive resource advantage, maybe we could've won if I didn't cheat/play to win (delete as apropriate) but it's not like we actually know.

Star Wars Battlefront while not a Strategy game dos have the greatest "flaw" of any Strategy game, the Slippery Slope. In this game there are soldiers and Command Posts, capturing CPs allows soldiers to spawn there and forces the enemy side to use another CP, which is why the last CP is always the hardest to capture. Each side has a pool of 200-250 lives, when someone dies the counter gos down by 1, there are something like 20 players/bots per side, so when the life counter for each team gets down to that number chances are they've already lost no matter what they do. Having more CPs than the other team also gives the benefit of the other team's life pool steadily draining, the problem with having more CPs than the other team (yes there is a downside) is that your forces are likely to be more spread out and they'd have the ability to sneak way to the rear side of your army and steal one of your more secure CPs from right under your team's nose. This along with a few superior players on the supposingly losing team, can lead to a very impressive comeback, yes comebacks are possible with a slippery slope.

Let's see examples of this, I play a lot of Left 4 Dead 2 online, Realism means when a Survivor is seperated from the rest of their team the other Survivors can't see a halo, when a survivor is under attack by a Special Infected the other Survivors still cannot see a halo and when one dies they stay dead the whole level, they don't respawn in some random closet. How the Slipper Slope works here, the Survivors lose running speed as they take damage, at 49HP for yellow and I think it's 19HP for red. When Survivors die they lose protection while healing and possible revivals when incapacitated, no revival while incapacitated leads to death. Now Realism Versus takes the rules of Realism and puts it into the much loved Versus mode, normally the Infected team attempts to pile on as much pressure as possible so the Survivors can't handle everything that's happening, when a Survivor falls during an attack and all Infected are dead. There's usually enough chaos happening so that in the time it takes to revive the fallen team mate, the Infected team have respawned and are ready to attack them again, knocking the newly revived team mate down, him screaming he's deadweight and begging the others to leave him, of course the Survivor team will be on a much lower level of ammunition and HP.

This has happened to me, my team mates and members of an opposing team several times, I loved grabbing a straggler and taking them out of sight, if their team mates aren't paying attention it can be very painful. This is where the big comeback comes in, on map 3 of Hard Rain Realism Versus I had as a Charger, managed to incapacitate and separate one of the Survivors by taking him from the top floor of the sugar mill, it wasn't the instant kil that would have been taking him back to where they came from, but it did force the other team to rush forward. I used a Charger later in the same round to bring a Survivor backward into the same area, we also got a Tank which proved invaluable in wrecking the HP of three of the Survivors, the other guy, the last man standing, instead of waiting around to be slaughtered as is polite (joking) in L4D2, ran leaving his team to die. Normally leaving your team puts you at risk, but the other three were grounded and a Tank was guarding them, I only noticed him running toward the safe room by spectator which the Infected side get between dying, we chased him through the remainder of the level and tried our best to stop him, but he had adreneline, skill and the sense to check behind himself for back attacks, needless to say, he made it to the safe room, we congratulated him on his "cheap" trick and let him know that he deserved to win that round, we of course took heavy damage in the sugarcane field and died very shortly after the Tank appeared.

The next map as a Jockey, I leapt onto the last man as he ran down the stairs leaving the saferoom, the rest of my team were already dead after dealing with the other three, I took the last man into the saferoom and toward the previous level before the others came in and saved him. My three team mates had respawned and were already harrassing the Survivor team as soon as they left the safe room again. They were within easy reach of their ammo supplies so the attrition only affected their HP, we were given a Tank not much later, just a few steps down the road. Of course one of the other team tries the same trick that won the last round for them, they make it to the last stretch, they were about to run through the safe room doors, but I as a Smoker snagged him and finished off their team. Same round our turn to be the Survivors, we were attacked by the other team as soon as we left the safe room, however our entire team through watching eachother's backs and knowing about my own cheap trick, the one that delated our opponents, managed to make it halfway through the level where the Tank appeared. We were slaughtered, I broke off from the group trying the trick the other team's last man had used previously, sadly not long afterward one of their team using a Boomer vomited on me, the surrounding Common Infected slowed me to a crawl, they took long enough for me to kill that my adreneline shot had worn off and I was stuck at normal speed, we all died halfway through the level. We still won because we managed to get much further than the majority of the other team.

The Slippery Slope enforces teamwork, which is what the main them of these games is about, lose one member and your overall effectiveness drops, in my opinion (which gets discounted because I'm not you) it is preferable to make a comeback from a Slippery Slope than it is to make use of a Perpetual Comeback. In Mario Kart 64 the Blue Shells punished the position 1st and had a chance to hit anything between 1st and it's user, in subsequent releases I've noticed how it locks onto the kart/player and can hit someone in 5th, sure the original could hit 5th on it's way to 1st, but it never aimed for 5th and it had a chance of failing depending on how a player fired it, yes in more recent releases the Perpetual Comeback is a part of the Slippery Slope. It isn't as much of a comeback item anymore because it has no chance of hitting anyone other than it's original target unless they're too close to the original target when it hits. I know it aimed for 1st place as a position in MK64 because of how in a 2 player race, whenever 2nd got and fired the Blue Shell while almost neck and neck, the Blue Shell would zoom forward, 1st would slam on the brakes and allow the other player to take 1st, the shell would aim for the user and thus 1st would belong to the player who had expertly avoided being hit by the Blue Shell. I've been hit by a Blue Shell on Mario Kart Wii while in 5th immediately after being assaulted by a Blue Shell 1st, a POW Block 3rd and a Mega Mushroom user 4th and that was from the AI, just to give my evidence of this.

Strategy games and other games that enforce teamwork through a Slippery Slope are the only games the majority of people who play by the "Play to Win" mantra and the so called "Scrub" players mostly agree with eachother, both sides mostly agree that people who don't play by the rules should be punished severely, there's some honour, such as when I went up against two other players in Star Wars: Empire at War, I was allowed to use a Hard AI, they didn't complain, they taunted me over using a Hard AI and laughed when I lost, but the AI was next to useless against just one player anyway and both winner did congratulate me for holding them off for so long.

Ride the Slippery Slope Sirlin, ride it and look for all the twists and turns, then maybe you'll find the one that takes you back to the top.

Oh yeah I'll leave you with a Fighting game that has a Slippery Slope, Super Smash Bros. The more damage a character takes, the further they'll fly when hit, it just so happens to have a very competetive community and is one of the main reasons to own a Nintendo Wii.

How many times have I said Slippery Slope anyway?

[Corbeau]

I would like to come back (again) on some points discussed before. These may be nitpickings but I though they might be worth saying.

First of all, Fighting games featuring combos necessarily incorporates some sort of period in which the game is actually over but is not technically over. In case I'm not clear, here is an example: Let's take Ryu vs Ken in SF. For arbitrary reasons, let's say Ryu is in a position in which he can pull off a 40% life combo and Ken has 39% of his life left. In this case, the instant the combo connects, the game is over (since the equality in skills between the players prevent the Ryu player from droping his combo) yet the KO has not been announced. The difference in pace and average length between SF and Chess or Starcraft make them appear different yet they are of the same nature: a chain of inescapable event that, since they lead to the ending of the game, are not "worth playing"; in other words, a forfeit.

Another point is that even fighting game generally features some sort of positive feedback. Let's take SF2X as an example here, and especially his "super move" feature. When hitting your opponent, you gain a certain amount of "special points" that fill a bar which, when entirely filled, allow your character to use a "super move". This a definitely a positive feedback since hitting your opponent give you a "raw" advantage (in life points removed) and a long term advantage (in additional moves). This is definitely game changing, especially in SF2X for characters like Ryu, Chun-Li or Boxer which rely heavily on supers.
However, some also incorporate some negative feedbacks: Ultras in SF4, for example, give your opponent an edge.

The third point I would like to comment on is the starcraft whole thing. One aspect of starcraft that seem to be underestimated here is economy (and especially the long-term oriented one). The example given in the article might not always be true, and here is what bothers me:
If my opponent kill one of my probes, I have one probe less than I should had he not did it. This is the basic idea developed in the article. However, in order to kill my probe, he had to make an attack and thus to produce units when I did not. Since he produced those units early, he did not invest as much as me in economy and thus, as long as he does no actual damage to my economy, I am at an advantage. This means killing my probe with an early rush of zealots may not be a good move for him, and that defending with just as few units as possible (even maybe taking some losses in probes) may actually be a good move for me. Interestingly enough, when a player manages to barely defend from an attack in units, he is the player at the advantage. Moreover, if I lost a worker, my food count is lower than my opponent which delays the moment I am going to need to build my supply, thus allowing me to rebuild my economy faster than my opponent can build his, allowing me to catch up (and as such being a partially negative feedback as well).
This long blabla just aim at demonstrating how it is not as simple as it appears (using Starcraft here as an example), and how it is very difficult to actually determine how much a feature influences the course of a game (leading to my fourth point with a very nice-timed transition indeed :D ).

The fourth point I'm not comfortable with is the idea that feedbacks are clearly identifiable in games. Most games do not rely on only one value in order to determine which player wins. For example, in a simplified fighting game, the two values used are the amount of time remaining and the difference between the player's life. The game end when the time runs out, or when one player's life bar is empty. As such, it is really difficult to determine whether a mechanic is actually inducing a feedback or not. To come back on an example I just used, ultras in SF4 take a long time before actually coming into effect. As such, even thought they hurt your opponent pretty bad, they also consume a lot of the precious time you might need.
An easy situation I can picture is for a Ryu player (again) who might either go for a f.HP > Shoryuken > Ultra 1 or go for a f.HP > c.MP > C.HP > Shoryuken. The first is the most damaging, yet the second is the fastest and might be the right move to pull off in the very last seconds of a round.

The last one (finally coming to a conclusion) that bothers me is the idea that positive feedbacks are necessarily bad features (yet they may not hamper the overall quality of a game). I would rather say that they change the way the game is played.
A fighting game is played mostly straight up: as long as you have some pixels left in your life bar, you can still fight since you are not at a global disadvantage in options (or mostly not). In games that incorporate some sort of important positive feedback options, the game is not played "in the structure of the game". What I mean is that the positive feedback allow for a second game (which is the actual game, the other one being only the support) to appear, on a superior layer: I believe it can be called a sort of meta game.
In case I'm not clear, let me take an actual example. A fighting game has rules: in the end of the round, the player with more health wins, the round ending when the time runs out or when a player has no life left. As such, players play the game in order to achieve those objectives: having more life, depleting the other player's life. In games that incorporate positive feedbacks, the game also have rules but they dictates situations in which the loss will be unavoidable (at equal skill levels). The players do not actually play the game: the play a more elaborate game, which takes place in the first one, which has the same rules as the first except you also need to avoid "unavoidable loss" situation, and have to force your opponent into one of those.
When playing starcraft, you don't actually try to build more buildings than your opponents, nor do your try to kill every enemy building you can see. You'd rather take out strategic structures that will cripple your opponent and will draw him closer to being into a "unavoidable loss" situation. What that means is that when a player admits defeat, he actually lost the game he was playing even tough the support in which it took place has not ended yet (and do not need to).
As such, it seems meaningless to try to compare which kind of ending to a game is better since having a game oriented toward actual end or toward forfeit is not only a "feature" but will change the very way the game is played. It is purely a matter of taste, and cannot be measured in terms of quality.

PS: forgive the length o the post as well as the possibles English mistakes / poor choice of word (since English is not my native language).

[Threadnaught]

I guess I may have been a little hasty and very wrong to say Advance Wars would have no Slippery Slope if you turned off Powers, set the map to a symmetrical 2 player one, funds on maximum and spammed Megatanks. In fact it still hase one, as units are damaged they lose firepower and take more damage, for example a Tank unit consists of five light tanks, when they're all together they can usually destroy Infantry and light vehicles without taking damage, when a Tank unit takes 2-3HP damage however they lose one tank and all the firepower it gave, because there's one less tank in that unit however, any enemy units also have less to target and can focus their own firepower doing more damage.

Some units when animation is turned on are made up of just one thing APCs, Megatanks, Piperunners, Transport Copters, Bombers, Stealths and all Naval units are what I'm reffering to, designated transport units APCs, TCopters, Landers and Black Boats don't have any firepower, so they don't lose anything except HP, the other units in the single sprite catagory lose 20% firepower for every 2HP they lose.

But still, instant respawn for units and little to no delay in them reappearing on the front line, the least amount of Slippery Slope possile in a strategy game and an example of how Slippery Slope can avoid Stalemate scenarios.

[Obscura]

Corbeau kind of covered this, but wouldn't Starcraft's supply mechanics make it a "limited" slipperly slope in the early/midgame, and a perpetual comeback in the late game? Early, it's cheaper to replace units than it is to expand your army, because you don't have to build supply depots; in the late game, when on 4 or more bases, and with supply counts at or approaching 200, you can build more units to replace losses, plus you get the advantage of your reinforcements not having to travel as far as an opponent's if he's pressing an attack, while your opponent simply can't build more than 200 supply of units.

[Sirlin]

Obscura, ok those things are true, but I think the much larger force is that when you lose units, those units can no longer attack. If dead units reappeared at your base or something, that would closer to neutral slippery slope. If dead units caused even MORE units to appear than you lost (for free) that would be perpetual comeback. Note that I'm not saying that's how it should be, I'm just describing what those terms mean.

I think no matter how you slice it, if you lose a battle and that means your attack power is less because you lost units, that's slippery slope. If the units you lost were worker units, it's like double-slippery slope and the game could end quickly (or be destined to end). Compare to a game like basketball where you don't lose players when the opposite team scores points (neutral slippery slope).

[Obscura]

But how is being less able to attack for a while any different from the "get swept in Street Fighter 2" situation, which you describe as a limited slippery slope? Admittedly, my fighting game knowledge is quite minimal (the last time I played a fighting game was SSF2T, back in the '90s, and my best tactic was to repeatedly throw my opponent and hope it worked because I couldn't execute anything else consistently), but it seems like the situations are similar- when you're swept (or dizzied), your ability to attack is reduced temporarily, but you get it back later. The supply mechanics in Starcraft cause a similar phenomenon for "army unit" kills; you're less able to attack for a while, but because you don't have to build supply and your opponent does, you'll regain that ability. In Starcraft, it's especially easy to come back from non-worker kills because the defender's advantage is so pronounced; it's not like in SSF2T, at least as I understood it (again, where my understanding was likely grossly flawed), where getting Swept/Thrown/Dizzied meant that there was a LARGE attacker advantage while you were trying to survive to get your full ability back. It seems that a "army unit kill" situation would only be a slippery slope in a game like Total Annihilation, where there's (effectively) no supply cap mechanic, the winner of a fight actually gained more metal by reclaiming the "corpses" left on the battlefield, and little to no defender advantage (if anything, that game might have a slight attacker advantage, simply because of the way the economy worked).

Total Annihilation is interesting in this context for another reason- even though the game is a crazy slippery slope, forfeits are entirely unheard of, and every game is fought until the bitter end. The reason is because the victory condition isn't to destroy all of your opponent's stuff. Rather, you only have to kill one of his units- the Commander. Snipe that unit, and even if you're FAR behind, you win. Furthermore, keeping the Commander "safe" in the back of your base, away from the action, was a terrible idea, simply because it was so much more powerful than any other unit in the game; keeping him tucked away would certainly set the slippery slope against you. This means that no matter how bad the chances of you winning are, you can (and should) hold out, because one bad decision from your opponent can give you a comeback, even if the chances are bad. I suppose it's like an RTS "ring out", except that there is a slippery slope, unlike in, say, Virtua Fighter (at least I assume VF has no slippery slipe; I've never played it).

[Sirlin]

The mechanic in Total Annihilation you described sounds interesting. Probably leads to exciting end games where both people are in it until the end, more so than other RTS. That would be my guess and it's what you said anyway.

Regarding the other thing, I'm sticking to my story. Yes it's a different kind of thing to lose units in an RTS than it is to get knocked down in a fighting game. When you get knocked down in a fighting game, you can't get "knocked down more." So the potential loss is capped. When you get back up, you have all the same moves that you had before you were knocked down. The opponent also does not gain entirely new moves. (To fighting game people: yeah I know he can go for crossups or meaties; I'm talking about like several seconds after you get up, everyone has the same moves as always).

When you lose units in an RTS, you can build them again...but *the opponent is building too*. If you had 4 units to his 10, got into a battle (your disadvantage) and lose, you might lose all 4 with him losing 0 because of the nature of focus fire and all that. Can you build 4 more later? Yes. But he can build 4 more too. Now it's 4 to 14 next time, which is even worse than before. This is the slippery slope. Losing a battle is NOT like losing points in some separate tally from gameplay. Instead, it reduces your ability to attack.

The analogy in a fighting would be if knocking down the other guy gave you bigger and bigger and bigger fireballs. His disadvantage would compound every time, because after several of these exchanges, he gets more and more likely to be knocked down and get further behind. Just like if I lose a battle and we both build more guys, your advantage compounds.

What you're saying is that supply limit means it *compounds less than it otherwise would*. Yes ok. The slippery slope is less than it otherwise would be with no supply cap (maybe? or maybe not even), but it doesn't reverse the flow of slippery slope and make it neutral.

[Threadnaught]

"The analogy in a fighting would be if knocking down the other guy gave you bigger and bigger and bigger fireballs."

Sorry Sirlin, but you're completely wrong, the analogy in a fighting game would be Super Smash Bros. There are a certain few atacks with no knockback, but every other attack causes knockback as well as damage, the objective in a basic match isn't to reduce the opponent's HP to 0, it's to knock the opponent off the screen. But starting knockback is so low it's almost impossible without the Slippery Slope that exists in this Fighting game, the Slippery Slope being that higher damage = more knockback, yes if you take too many hits a good attack will send you flying off the screen giving your opponent a KO. KOs start happening reliably at 100% or above, but I've been able to survive over 300% and not just in Sudden Death, the knockback was horrible, every hit I took I thought was gonna be the last, but I could still come back and even the odds, but one clean hit ended up finishing me when I failed to dodge or missed an attack.

[Sirlin]

...

[Syraine]

*total laughter* Please, do not worry Sirlin.

Your work here is done.

[mikhail]

I completely disagree with the article.
This makes no sense to say slippery slope is a bad thing. Slippery slope as explained in the article is an arbitrary set of facts, mechanisms, phenomena, quite different in their nature and effect on gameplay. In chess and starcraft it is phenomena created by relations and dynamic of tactical values in the course of the game and they are no more good or bad then say different score values of pinball objects. In fighting games they are deliberate mechanisms to make tactical values of different actions. It is done bad in Bushido Blade and good in Street Fighter. The same could be said about perpetual comeback.
And giving advantages to a player making good decisions (or performing well) and not giving them to one making bad decisions is obviously a good general rule.