作者：Brice Morrison

[本文是《解析“滑坡效应”机制在游戏设计中的运用》姐妹篇，解释了“无限恢复”的作用和原理。]

与游戏中的“滑坡效应”这个概念相反的，我称之为“无限恢复”，其实就是负反馈的另一种叫法。（游戏邦注：作者认为负反馈听起来很不详，但事实上游戏中的负反馈通常不坏，所以最好给它一个积极一点的名称。）负反馈在游戏中的作用，就相当于保持室内温度恒定的温度调节器。

无限恢复实际上是默默地帮助了失利的玩家。我想对两类效应加以区别。其一，当你落后时，无限恢复就是一股扭转不利形势的力量。《虚幻竞技场》中的大男孩增变基因就是一个例子。在FPS模式下，当你杀死一个敌人后，你会变得更肥大但更易被击中。当你挂了，你会变得更瘦小但更难被击中。所以如果你一死再死，你就会越变越瘦小。注意，虽然你挂了N次，仍然在损失（你的得分也没用），但你确实获得了优势（更难被击中）。

Mario-Kart-DS-nintendo(from fanpop.com)

相似的例子也出现在《Mario Kart》所有版本中。你越是落后，你得到的道具就越强大。最后，你可以得到强大的蓝海龟壳，这个道具能够自动对准跑在最先的赛车开火。同时，跑在最前的赛车只能得到最差的道具。

任天堂DS的《Advance Wars: Dual Strike》也有相似的特点。双方的仪表上各系有一个强大的“标记攻击”。当你被攻击时，你的仪表填满速度将是平时的二倍，所以落后的玩家会有更快的速度来发动进攻，这样，他自然就有机会恢复。

在以上三个例子中，游戏中存在一个“扶弱惩强”的力量。这个力量存在的积极意义在于，拉近了玩家之间的差距，削弱了前面犯下的错误造成的影响。也就是说， 在《Mario Kart》中，这股力量可能太过极端，或者说创造了一种奇怪的人为作用，如避免某位玩家长期占据比赛的第一名。而在《Advance Wars: Dual Strike》中，标记进攻的效应可能过大，使其始终支配着游戏。撇开争议不说，这个概念仍然是合理的，运用得好的话，可以让玩家之间的差距更接近、比赛更刺激。

极端的无限恢复

另一种无限恢复走了极端，这是比较少见的。所谓过头的无限恢复就是，当你落后时，这个劣势不仅是扶了你一把，而且等于是直接把你拉到领先地位。我认为最典型的例子就是《Puzzle Fighter》。

个人认为，在我担任《Puzzle Fighter HD Remix》首席设计师以前，我就认为《Puzzle Fighter》是迄今为止最好的益智游戏。这款游戏看起来够水准——玩家各有一个面板接着落下的棋子。玩家要用游戏中的四个同色碎片构成更大的单色矩形（能量宝石）。你之后可以用碰撞宝石将那些矩形破坏掉。你打碎的越多，你丢到对手一边的垃圾就越多。当你的一方“封顶”，你就输了。

促成《Puzzle Fighter》中的无限恢复（极端版）有若干因素。首先，各个“角色”（共计11人，包括神秘角色在内）都有不同的“空投特征”，即当该角色粉碎己方的矩形时投向对手的色块特征。例如，Ken的空投特征依次是水平红排、水平绿排、水平黄排和水平蓝排。每次Ken向对手投出的色块不多于6个时，就是一个水平红排；而当Ken投出12个色块时，就是一个红排再加一个黄排。因为敌人知道这点，所以可以早做打算，将Ken的进攻转化为自己的优势。比如，当你向对方投色块时，这些色块会变成“反击宝石”，不能马上被破坏，也不能组合为致命的能量宝石。过了五次行动，反击宝石就会转变为常规宝石。

另一个非常重要的特点是，在屏幕上位置越高的能量宝石破碎后，造成的破坏（投出反击宝石）会比下层的宝石更大。所以想想这款游戏的实际伤害是怎么样的吧。进攻其实只是暂时性伤害，直到反击宝石转变为常规宝石。此时，对手可能会将这些宝石组合进自己的宝石中，因为对手知道你的空投特征。即使对手不能以这种方式从你的进攻中受益，他仍然可以通过破坏你投给他的所有东西而“逃出升天”。对手的屏幕填得越满，反过来轰炸你的炮弹就越多。而且，因为对方快撑不住了，他的攻击会因为高度带来的额外效应而呈现最大的伤害。越是高端的宝石，破坏后释放的杀伤力更大。

《Puzzle Fighter》具有极其罕见的特点，即“几乎失败”正是“几乎胜利”。比如说你破坏了大量能量宝石，给对手以重大打击。你自己的屏幕几乎被清空了，那么你就赢了对吗？而对方的屏幕几乎封顶了，他输了，对吗？好吧，他只是挣扎在失败的边缘，但他拥有所有的弹药和额外优势，而你这一边却无所防御，你的对手同时处于“失败”和“胜利”的边缘。确实非常奇怪吧！

Puzzle Fighter(from from-thegameprodigy)

如上图，Ken （左）几乎输了，但他及时得到所需的黄色碰撞宝石。最终Donovan（右）会输。

玩《Puzzle Fighter》的最好策略就是非常小心地规划自己的宝石，不要一次打到底。不然你就是反过来帮对手一把了。你得存着一些用来打击对手。你的对手总是有足够的进攻来杀掉你，所以你得有足够的防卫。无论一开始局势如何有利于对手，运势也会一定程度上向你倾斜。只要不到最后一刻，输赢就没有定论。这款游戏被戏称为“卷土重来”，因为刺激总是持续到最后一秒。

结语

“滑坡效应”是对落后者的惩罚，让他们落得更后面。如果不加抑制，会使游戏预先区分出真正的胜利者，结果必然是损害游戏玩法，让玩家倍感无趣。虽然格斗游戏缺少这种彻底的滑坡效应，但确实存在若干临时性、有限的滑坡效应，从而增强了玩法。这种受限的滑坡效应可能也存在于其他类型的游戏中，但在未来的游戏设计中，设计师们可以有意识地采用这种形式。最后，无限恢复，即滑坡效应的对立面，是一股帮助落后玩家、阻碍领先玩家的力量，从而缩小竞争的差距。如果使用不当，这个属性非常容易走极端；但如果使用得当，游戏将会更加好玩刺激。《Puzzle Fighter》将这一概念运用得淋漓尽致，从而给玩家带来一种“若输若赢”的感觉。（本文为游戏邦/gamerboom.com编译，拒绝任何不保留版权的转载，如需转载请联系：游戏邦）

Game Design Profile: Perpetual Comeback (Part II)

by Brice Morrison

[Editor: In this guest post from David Sirlin, he discusses the sister design to a slippery slope, the perpetual comeback, and how it works.]
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.（source:thegameprodigy）