作者：Max Seidman

什么是引擎创造？

许多欧式或业余的桌面游戏都让玩家能够创建一个引擎。这便意味着他们经常会去收集能够带给自己特殊能力/更多资源的纸牌或组件。特别是，为了成为引擎创造者，“引擎块”必须给予玩家能够帮助他们最终获胜的资源或能力。

我将在此以《卡坦岛》和《大富翁》为例，因为它们都是知名的引擎创造游戏（尽管并非最佳设计游戏）。在《大富翁》中，玩家会创建能够带给自己收入的引擎。玩家在游戏中购买的每种财产和房子都是引擎块，因为这让他能够从敌人那里得到钱，并帮助自己去购买更多财产和房子，从而为自己赢得最后的胜利。之所以说《卡坦岛》是一款引擎创造游戏是因为每个殖民地和每座城市都能带给玩家资源和胜利点数。当他获得更多资源时，他便能够创建更多引擎块，并因此获得更多资源和胜利点数！

引擎创造游戏之所以有趣是因为它们能够带给玩家一种进程感。在每个新回合中玩家都能够感受到比上一回合更大的能量，并能执行更酷的组合或获得更多资源收入。在游戏最后，就像在益智游戏中那样，玩家可以回头看看自己的进程。在游戏中变得越来越好是种很棒的感受！有时候这种感受是通过发现新策略或更巧妙地游戏而呈现出来。引擎创造者追求的是通过让玩家在游戏过程中提升自己的能力水平而创造出这种进程感。

到底什么是能量级别？

我将引擎创造游戏中的“能量”定义为带你靠近胜利并完善你的引擎的能力。这是关于你在游戏系统中拥有多大的影响力。能量级别通常都是以不断提升的资源收入表现出来，这通常是引擎块所提供的。所以在《大富翁》中，当你购买并开发更多财产时，能量级别便会上升。在《卡坦岛》中，当你创建了殖民地和城市时，能量级别也会提升。这些内容都能帮助你更加靠近胜利的终点，同时也能提供给你更多资源。

我将基于不同回合绘制能量级别。需要注意的是我在此呈现的平滑曲线是抽象的，真正的能量级别将基于每个人的回合上升。

为什么能量曲线的形状如此重要？

从设计师的角度来看，当玩家在桌面游戏中为了获胜而与其他玩家相抗衡时，许多不同的玩家将成为某一游戏过程中的领导者，并且直到最后我们才会知道谁才是真正的胜者，并且那时候的游戏分数才是真正准确的。

在这方面，引擎创造游戏的问题在于你可能注意到，我在说引擎创造者如何行动的措辞与我所说的积极的强化循环非常相似。之所以会这样是因为我们真的很容易设计一款通过提升玩家引擎的能量而不断推动他们前进的引擎创造游戏。在并非为了减少积极强化的引擎创造游戏中，两个玩家的能量曲线可能如下：

exponential power curves（from mostdangerousgamedesign）

在这里，蓝色代表主要的玩家，因为它是走在红色前面。尽管它们的能量曲线是基于相同的形状，即即时提高蓝线推动着玩家向前，让游戏止于红线之前。就像之前所提到的，这会让红线（以及游戏中的其他玩家）看起来像垃圾。

需要做出的妥协是玩家必须仍然能够在每个回合让他们的引擎趋于强大，但是设计师必须确保引擎的能量曲线在游戏最后能让玩家尽可能靠得更近，而不管运气怎样（理想的情况是大多数情况下都是更有技能的玩家获胜）。

理想的曲线总是能够处理恒定的能量级别，如下。如果能够获得最大的能量级别，那么所有玩家都将靠近这一能量级别，并在游戏最后更加靠近彼此。

asymptotic power curves（from mostdangerousgamedesign）

不止如此，当玩家更加靠近彼此时，他们也将获得大量的机遇去超越彼此。这也将提升紧张感和不确定性（即关于谁会获胜）。同时，玩家也仍在每个回合中不断前进着。这种渐进的形状便是引擎创造游戏中的理想能量曲线。

对于任何一款游戏，即使你获得了渐进能量曲线，你仍需要确保游戏能够长久地持续着，从而让玩家可以进入之后的曲线区域，否则曲线的形状便不再那么重要了。

当然了，对于设计师来说最大的问题是：“我们能够使用怎样的方法去塑造这样的能量曲线？”以下是我所列出的引擎创造游戏用于获取渐进能量曲线的三种方法。当然并不是只有这些方法，但是它们却被广泛用于游戏设计中。

1.引擎或获胜

到目前为止我最喜欢的关于获得渐进能量级别的策略是让玩家在每个回合中选择是否想要将自己的引擎变得更加强大，或者是否想要朝着胜利之门前进。一方面，让自己的引擎变得更加强大将让玩家更大步地朝着未来的胜利进军。另一方面，如果他并未开始将引擎能量调向胜利状态（通常是胜利点数），那么在敌人结束游戏前他便没有足够时间做到这点。

《银河竞赛》便是这一方法的典例。在这款游戏中，主要资源是你手上的纸牌数量。这既是你为了获取胜利点数并握住更多纸牌而操控的引擎块，同时也是你付钱去获取的引擎块—-在手上操控一张纸牌，你通常需要抛弃一部分其它的纸牌。通常情况下，游戏玩家的引擎块能够创造出产品。存在两种方法去购买这些产品：玩家可以通过“交易”获得它们，这意味着摆脱某些产品并抽一些纸牌，或者玩家可以“卖掉”它们，即摆脱该产品并获得一些胜利点数。在游戏早期，交易非常重要，而在后期它会出现在一个特殊的战术点上，因为离开了它你就不能创造引擎。然而，如果玩家忽视了产品销售并尝试着创造最大且最糟糕的引擎，他们可能就不会获胜（这也是我经常遇到的问题）。

《Dominion》进一步延伸了这一设计策略。在玩家的回合中，他既可以购买行动纸牌添加到自己的桥牌上——这让他能够在之后的回合获得更多钱去购买更多行动，他也可以购买胜利点数纸牌并添加到自己的桥牌上。这一纸牌将帮助他在游戏结束时获胜，但当他抽一个胜利点数纸牌而不是行动时，这便会拉慢其引擎的速度。这便意味着当玩家选择开始尝试着去争取胜利时，他并不只是放弃创造更强大的引擎，他们也将积极地将其变得不再那么强大。很明显，这会让其他玩家有时间去创造自己的引擎并追赶上来，并行程渐进的能量曲线。

这一机制为游戏添加了一种强烈的紧张感，这在游戏玩法中具有很强的吸引力。也就是说，尽管这是你的欧式游戏中所使用的优秀机制，但它却不适合出现在更休闲的游戏中。就像我之前在有关面向所有人设计游戏的文章中提到的，休闲用户很难忍受每个回合都要做出困难的策略选择的要求。这一机制可能会增加其中的一种选择。

2.资源上限/触发

资源上限是一种策略，即当玩家到达一定能量阀值时，他们便不能继续往上走了。使用一种资源上限方法，游戏系统将有效地说：“你可以尽可能创造出强大的引擎，但它却不能超过这一上限。”因此，在主要玩家到达这一资源上限的同时，其他玩家还有时间去追赶他，这也是渐进能量曲线的要点！

《Munchkin》便带有手牌上限，但也许更重要的是它限制了玩家的道具插槽。在游戏中，你可以双手，头，脚和身体都配备这一个道具。尽管你可以用现在的道具去换取全新且更好的道具，这仍意味着对于那些已经拥有一整套道具的玩家来说，每抽出一张纸牌都是最低限度的完善。而对于那些还未拥有一整套道具的玩家来说，每抽出一张纸牌便是一次很大的进步。再次，这一机制也将构成渐进能量曲线。

这一设计策略能够应用于许多游戏中，我也由衷建议你将它带到自己的游戏，不过前提是合适的话。这并不会添加更多复杂性，同时还能玩家玩家完成更紧密的能量级别。

3.社交压力

实现主要玩家的能量曲线（从线性或者指数到渐进）的最简单的一种方法便是利用游戏的社交元素：也就是，所有玩家团结起来去阻碍主要玩家获取胜利。当这种情况能够出现在带有玩家整合的任何多人游戏中时，它似乎更有可能出现在游戏玩法依赖于玩家自由交易资源或引擎组件（游戏邦注：通常不会是与主要玩家进行交易）的游戏中。

这种行为类型将推动主要玩家的能量曲线趋于渐进，因为当他的胜算越大时，对手将更加严格地阻碍他所需要的交易。如果你想要在设计中使用这一策略，你必须注意自由交易也有自身的机制，并且这对于游戏玩法来说非常重要（并不能作为事后添加的内容）。鉴于此，玩家必须谨慎地对待交易才有可能获胜。我们会发现玩家并不总是擅于判断当前谁出于主要位置，以及怎样做才能打压目标玩家。因此使用这一设计的游戏需要让每个玩家玩一次特别的社交游戏：做得好但却不会让人觉得他做得好，这从设计角度来说可能是最让人满意，也有可能是最让人反感的。

（值得一提的是，尽管《大富翁》是使用这一设计策略的引擎创造游戏，其主要玩家的能量曲线却非渐进式，而是最糟糕的情况：主要玩家以指数发展，并逐渐远离失败的玩家。这一策略可能会在游戏中间拉平主要玩家的曲线，但通常情况下却不是那么重要。）

这只是一些现有的游戏使用的一些能量曲线机制。许多游戏会利用自己特殊的系统去执行机制并形成自己的能量曲线，而换做在其它游戏中，这种方法可能就失去了意义。如果你正在设计一款引擎创造游戏，你应该认真思考自己想要怎样塑造玩家的能量级别，因为如果执行得当，你将能够有效地完善玩家的游戏体验。

（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）

Engine Building and Power Curves

by Max Seidman

Max writes about the paradox of the desire to let players feel good by gaining power quickly in board games, while at the same time not letting them pull ahead of their opponents.  He discusses the use of “asymptotic” power progression, why it’s desirable, and gives examples of mechanics that designers can utilize to achieve this type of progression.

What is engine building?

Many euro-style and hobby boardgames allow the player to build an engine.  This means they often collect cards or components that give them special abilities and/or more resources.  In particular, to be an engine builder, the “engine pieces” have to give players resources or abilities that will eventually help them win.

I’ll be using Settlers of Catan and Monopoly as examples for this post because they are both well known engine building games (although not necessary well designed ones).  In Monopoly the player is building an engine that gives her income.  Each property and house bought in the game is an engine piece, because it allows her to then take money from her opponents, which will both help her buy more properties and houses, and will also eventually cause her to win.  Settlers of Catan is an engine builder because each settlement and city gives her resources as well as victory points.  As she gets more resources, she can build more engine pieces, which then give her yet more resources and victory points!

Engine building games are fun because they give the player a feeling of progression.  Each turn the player feels more powerful than the last, and can execute cooler combos or secure more resource income.  At the end of the game, much like in puzzle games, the player can look back and see her progression, how far she has come.  Getting better at games feels good!  Sometimes this manifests as discovering new strategies or simply getting smarter about how you play.  Engine builders seek to somewhat artificially create this feeling of progression through allowing the player to increase their power level over the course of the game.

What the heck is a power level?

I define “power” in engine-building games as the ability to bring you closer to victory and to improve your engine.  It’s how much influence you have over the game system.  The power level usually comes in the form of increased resource income, and it’s always provided by the engine pieces.  So in Monopoly power level goes up as you buy and develop more properties.  In Catan power level increases as you build settlements and cities.  Both of these things bring you closer to winning, while at the same time providing more resources.

You can’t see power level with one of these.

In a second I’m going to be graphing power level by turns.  Note that the smooth curves I’m showing are abstractions, and in reality power level would jump up on each person’s turn.

Why does the shape of the power curve matter?

From a designer’s point of view, when players sit down to compete against one another for victory in a board game, many different player should be the leading player over the course of the game, the winner shouldn’t be clear until late in the game, and at the end of the game the scores should be as close as possible.

The problem with engine building games in this respect is that you might have noticed the way I phrased how engine builders work sounds suspiciously similar to the way I phrased positive reinforcement loops when I wrote about them in The Hunger Games.  They sound similar because it is really easy to design an engine building game such that a player who goes first or randomly gets lucky pulls further and further ahead by continuously increasing the power of her engine.  In an engine building game that is not built to reduce positive reinforcement, the power curves of two players might look like this:

In this case blue is the leading player primarily because she went before red (or perhaps got a lucky draw early).  Even though their power curves have the same shape, that slight boost in time that blue got allowed her to pull ahead, ending the game much farther ahead of red than they started.  As mentioned above, this will make red (and any other players in the game) feel like crap.

The compromise that must be made is players must still be able to make their engines more powerful each turn, but the designers must make sure that the power curve for the engine leaves the players as close together as possible at the end of the game, regardless of luck (ideally with the more skilled player winning most of the time).

The ideal curve, then, is one that approaches a constant power level, as below.  If there is a maximum power level that can be achieved, then all players will approach that power level and be close to one another as the game ends.

Not only that, but as players get closer together, they will have ample opportunity to surpass one another.  Because they get closer together as the game ends, this generates a sense of increasing tension and uncertainty surrounding who’s going to win.  Meanwhile, however, players are still progressing every turn!  This asymptotic shape is ideal for power curves in engine building games.

With any game, even if you achieve asymptotic power curves, you still have to ensure that the game actually goes on long enough to get the players into the latter regions of that curve, or else the shape of the curve doesn’t matter very much.

Of course the big question for designers is: “What methods can we use to shape the power curves this way?”  Below are three methods I’ve identified and ranked that have been utilized in engine building games to achieve asymptotic power curves.  These are by no means the only ones, but they can be broadly applied when designing.

3. Social Pressure – Settlers of Catan, Monopoly

One of the simplest ways to force a leading player’s power curve from linear or exponential to asymptotic is by leveraging the social elements of the game: namely, all players teaming up to keep the leading player from winning.  While this can happen in nearly any multiplayer game with player interaction, it seems to arise most easily in games where gameplay relies on players freely trading resources or engine parts, and often takes the form of trade embargoes with the leading player.

This type of behavior forces the leading player’s power curve to be asymptotic, simply because the more she seems to be winning, the more stringent her opponents will be in giving her favorable (and necessary) trades.  If you want to utilize this strategy in your designs, carefully note that free trading is its own mechanic, and should be central to the gameplay (not tacked on as an afterthought).  For it to matter, players must have to trade well to win.  Do note that players are not always good at telling who is currently leading, which can be frustrating for the targeted player(s).  Thus, a game that employs this kind of design makes each player play a very specific kind of social game: do well without looking like she is doing well, which can be desirable or undesirable from a design standpoint.

(It’s worth mentioning that although Monopoly is an engine builder that employs this design strategy, its power curve for the leading player is not asymptotic, but perhaps the worst case scenario: exponential for the leading player while turning asymptotic for the losing players.  This strategy probably flattens out the leading player’s curve somewhat in the middle of the game, but usually doesn’t really matter.)

2. Resource Caps/Penalties – Munchkin, DC Comics Deck-Building Game

Resource capping is a strategy where, once player reach a certain threshold of (at least one facet of) power, they can go no higher.  Using a resourcing capping method, the game system is effectively saying: “you can make your engine as powerful as you want, but it’s never going to get you past this cap.”  Thus, while the leading player is sitting at the resource cap, the other players are given time to catch up–which is exactly the point of asymptotic power curves!

Munchkin does a fairly good job here by having a hand limit, but perhaps more importantly by limiting the player’s item slots.  In the game, you can have items in your 2 hands, one for your head, one for your feet, and one for your body.  Even though you can trade out current items for new and better ones, this still means that for a player who is sitting on a full set of gear, each card drawn is a minimal improvement.  For a player who doesn’t have a full set of gear, each card drawn can be a huge step up.  Again, this mechanic will definitely form asymptotic power curves.

Note the item slot in the bottom left.

This design strategy can be applied to many games, and I’d heartily recommend applying it to yours, if it fits.  It usually doesn’t add too much complexity, while still helping players finish with close power levels.

1. Engine or Win, Not Both – Dominion, Race for the Galaxy

By far my favorite strategy for ensuring asymptotic power levels is to make the player choose, each turn, whether she wants to make her engine more powerful or whether she wants to make progress towards winning.  On the one hand making her engine more powerful will allow her to make greater strides towards winning in the future.  On the other hand, if she doesn’t start turning her engine’s power into victory conditions (often victory points) soon enough, she might not have enough time to do so before her opponents end the game.

Race for the Galaxy is a fantastic example of this approach.  In the game, the primary resource is the number of cards in your hand.  These are both the engine pieces you play in order to get victory points and more cards in hand, but also the resource with which you pay to play those engine pieces–to play one card in your hand, you often have to discard a handful of others.  Frequently, some of the players’ engine pieces (which they have played in front of them) produce goods.  There are two ways to consume these goods: players can either “Trade” them, which means to get rid of the good and draw a number of cards, or they can “Sell” them, which means get rid of the good and gain a number of victory points.  Trading is vitally important early game, and at specific tactical points in the late game, because you cannot develop your engine without it.  However, if players neglect to sell their goods and try to build the biggest baddest engine, they will probably not win (which is the problem I always run into).

Dominion takes this design strategy a step further.  During her turn, a player can either buy action cards to add to her deck, which will allow her to get more money in future turns to buy more actions, or she can buy a victory point card to add to her deck.  This card will help her win when the game is over, but it actually slows down her engine when she draws a victory point card instead of an action.  This means that when players choose to start trying to win, they are not just forgoing making their engine more powerful, they are actually actively making it less powerful.  Clearly, this allows the other players time to build their engines up and catch up, forming asymptotic power curves.

“I want these Victory Point things, right?”

This mechanic adds an exquisite tension to the game, which I find extremely appealing in gameplay.  That said, while this is a great mechanic to utilize in your euro-style games, it is less amenable to use in more casual games.  As I mentioned in my post about designing games for everyone, casual audiences tend to be turned off by the necessity of making difficult strategic choices every turn.  This mechanic definitely adds one of these choices.

These are only a small taste of mechanics by which power curves are shaped in some already existing games.  Many games leverage their specific systems to implement mechanics to shape power curves in ways that wouldn’t make sense in other games.  If you are designing an engine buidling game, you should think long and hard about how you want to shape your players’ power levels, because when done well it improves the players’ play experience.(source:mostdangerousgamedesign)