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游戏设计课程之设置游戏平衡性技巧(16)

作者:Ian Schreiber

资深玩家或游戏设计师玩游戏,不论表现很好,还是很差,他们都会评论游戏的平衡性。和“有趣”这个词一样,平衡性的种类纷繁多样,我们今天的主题是探究游戏平衡性的含义及其重要性所在。(请点击此处阅读本系列第1第2、第3、第4、第5、第6、第7第8、第9第10第11第12第13第14第15第17、第18课程内容

平衡未能达标的游戏完全就是浪费时间,调整完核心机制后,你需要再次平衡游戏。现在我们手中握有的是经过多回合测试的半成品,是时候该进入下个步骤。

什么是游戏平衡性?

在双人游戏中,“平衡”通常指所有家都不具有任何不公平优势。但此词也也出现于单人游戏中,其中游戏玩家未面临任何除游戏本身外的对手,游戏可能存在的“不公平优势”可以视作挑战。我们也许会说《Magic: the Gathering》的个人纸牌具有“平衡性”,即使是在所有玩家都能接触这些纸牌的情况下,这样任何个人都未存在任何有利条件。这里出现什么情况?

Magic the Gathering from wizards.com

Magic the Gathering from wizards.com

就我的经验来看,通常我们谈论“游戏平衡性”主要指下列4种情况。具体情境通常能够清楚呈现我们谈论的是哪种情况:

1. 在单人游戏中,我们以“平衡性”形容挑战水平是否适合用户;

2. 在非对称多人游戏中(游戏邦注:即玩家起始位置和资源不同),我们以“平衡性”形容某玩家的起步是先于其他玩家。

3. 若游戏存在多种获胜策略或路线,我们以“平衡性”形容某种策略是否优于其他策略。

4. 在包含若干类似物件的游戏机制中,我们以“平衡性”形容物件本身,尤其是判断不同物件是否具有相同成本/效益比例。

下面我们就来详细分析各点内容,然后我们会重温平衡游戏的若干实际技能。

单人游戏的平衡性

在单人游戏中,我们以“平衡性”形容挑战水平是否适合用户。

注意通过体验游戏,用户最终会变成熟练玩家。这就是为什么电子游戏的后期关卡要比前期困难得多。形容单人游戏难度随时间而变化的专有名词是:节奏。

游戏设计师此时面临一个明显问题:我们如何把握什么是“合适”挑战水平?当然我们知道瞄准成人的逻辑/谜题游戏要比同类儿童游戏复杂很多,但除此之外,我们如何知晓什么太难,什么太简单?最明显的答案就是:游戏测试。

但这依然存在另一问题:不是所有玩家都一样。即便就小范围的目标用户而言,他们依然呈钟型曲线分布,有些玩家非常老练,而有些则相反。在进行游戏测试时,你如何知晓玩家分布在钟型曲线的何处?若你只是涉猎测试,最理想的方式是覆盖大面积的测试者。当你获得大量用户的反馈信息时,你就能够大致知晓总体分布。随着设计经验的增多,你对用户的了解就会越多,此时你只需通过少量用户便能得到同等有效信息。

即便你清楚如何调整游戏难度,目标用户置身何处,面对用户多元化的情况,你如何选择游戏挑战水平?无论你采取什么措施,游戏总是在某些人看来太难,而在某些人看来太简单,所以你将处于必输局面。若你必须选择某种水平的关卡,根据概测法,你通常会瞄准曲线的中间部分,因为这样你能够囊括最多用户。另一方式通过提供多种难度水平、障碍或系列规则组简化或强化内容,从而起到支持两端用户的目的。

非对称游戏的平衡性

在非对称性多人游戏中(游戏邦注:玩家未基于同等位置和资源出发),我们以“平衡性”形容某起点位置是否更易于获胜。

围棋 from appjidi.com

围棋 from appjidi.com

真正对称的游戏很少。在我们看来,国际象棋、围棋之类的经典游戏具有对称性,因为每个玩家都以相同棋子数量开始游戏,遵照相同规则,但这里存在一个不对称情况:有个玩家可以先走!若你修改游戏,让两个玩家悄悄在纸上写下自己的操作,使得移动能够同时进行,游戏就具有完全对称性。

这带来一个有趣问题:若游戏具有对称性,你是否就无需担心游戏的平衡性?毕竟两位玩家都以相同资源和初始位置开始,所以从定义来看,没有玩家具有不公平优势。这完全正确,但设计师需考虑其他类型的平衡性,尤其是游戏是否存在优势策略。只是让所有玩家处在同等位置无法令你摆脱困境。

纵然游戏具有非对称性,你为何要费神进行平衡?一个简单的答案是:玩家通常希望在其他条件都相同的情况下,游戏不会给予某玩家任何天然优势或劣势。

非对称游戏通常更难于进行平衡。越是不对称,测试过程就越要谨慎进行。达到此种平衡的一个最简单方式是建立各玩家间的资源联系。若你设定在游戏玩法中,1个苹果等于2个橘子,那么以1个苹果开始游戏的玩家就与以2个橘子着手的玩家就保持平衡。

有时,玩家间的差异很大,无法进行直接比较。有些游戏不仅给予玩家不同起步资源和位置,还提供不同体验规则。有些玩家能够特别享有某些资源或技能。游戏常见的一个不对称情况就是向玩家呈现不一致的目标。直接比较玩家的难度越大,游戏测试的工作量就越艰巨。

游戏策略的平衡性

若游戏具有多种获胜策略或路线,我们以“平衡性”形容某策略是否优于其他策略。

也许有人很好奇为什么要费心于此?若游戏顾及各种策略,但某策略比其他策略强大,利用最佳策略不就等于让玩家获得胜利?只要没有任何玩家具有不公平优势,游戏转变成“找到最佳策略便胜出”模式有何不可?

这里的问题是,只要找到优势策略,聪明的玩家就会忽略所有次佳策略。所有非优势策略组成要素的内容瞬间就会变得无关紧要。嵌入单一制胜策略的游戏本身并未存在任何问题,但在这种情况下,设计师应该移除次佳策略,让游戏变得更合理。若你融入次佳选择,这些就会变成错误决定,因为游戏只有一个解决方案。

若融入多个潜在获胜策略很有必要,那么这些策略富有平衡性会让游戏更有趣。而这些归根到底都在于游戏测试。在这种情况下,当玩家体验你的作品时,查看是否存在某策略的运用频率超过其他策略的情况,哪种策略更倾向带来胜利。若游戏有若干道具供玩家购买,是否有哪些道具玩家会优先购买,而其他道具则鲜少有人问津?若玩家在每个回合都具有行动选择,每次测试的赢家是否进行某操作的次数比其他玩家多?

单凭游戏测试无法证明某策略缺乏平衡性,但这清楚说明你需要就游戏的某些内容进行深入剖析。有时,玩家采取某策略是因为它非常显眼或简单,而非由于它是最佳选择。有些玩家会回避那些过于复杂或需要技巧的内容,即使这些内容长久来看作用显著。

游戏物件的平衡性

在包含若干相似物件的机制中(游戏邦注:例如集换纸牌游戏的纸牌,角色扮演游戏的武器),我们以“平衡性”形容物件本身,尤其是不同物件是否具有相同成本/效益比例。

这种平衡性主要瞄准给予玩家若干物件选择的游戏类型。下面是几个例子:

* 集换纸牌游戏的纸牌。玩家基于所收集的系列纸牌创建牌组。选择添加哪些纸牌是游戏结果的关键,设计师试着让各纸牌保持平衡性。

* 某些战争游戏和即时策略游戏的道具。玩家能够在体验过程中购买道具,不同道具具有不同能力、移动率和战斗优势。设计者需试着让这些道具保持平衡性。

* 角色扮演游戏中的武器、道具和魔力等(不论是桌面,还是电脑/掌机内容)。玩家也许会购买这些内容应用于战争中,这些道具具有不同成本、统计值和能力。设计师需让这些物件保持平衡性。

所有这些情况都要确保达到两个目标。首先就是防止游戏物件过于薄弱,相比其他物件变得微不足道。再次变成玩家的错误选择,因为他们很快就会发现自己得到或购买的物件缺乏使用价值;因此物件完全是在浪费玩家的时间。

第二个目标是防止游戏物件过于强大。任何变成优势策略的游戏物件都会让其他物件在对比之下变得毫无用处。通常若你需选择制作过弱或过强物件,最好还是朝过弱靠拢。

若两个物件具有相同成本/效益比例,他们就具有平衡性。也就是说,你获得某物件的代价应同你从物件中得到的利益相称。成本和利益无需完全一致。但当比较两种不同物件时,成本/收益比例应大致相同。

平衡游戏物件的方式:传递性、非传递性及独特性

我遇到3种平衡游戏物体的基本方式。首先就是所谓的传递关系。用更通俗的话说,就是成本曲线。这是平衡游戏物件最直接的方式。大体就是找到预期成本/收益比例。这也许呈线性分布,也许呈曲线态势,完全取决于游戏,但游戏测试、实验和直觉能够帮你判断它们究竟属于什么关系。

下步就是将所有成本和利益简化至某些能够比较的数值。将物件的所有成本累加起来;同样合计所有收益。比较二者,看看成本是否创造合理的数值回馈。

此方式通常用于集换纸牌游戏。若游戏有既定成本曲线,那么通过既有混合效应创造新纸牌就简单得多。在《Magic: the Gathering》中,若你想要创造包含既有颜色、能量、韧度和系列标准技能的新生物,其中已知某些成本,设计师便能够准确告诉你对应成本是多少。融入更多技能就会带来更多成本,降低成本就需要移除某些统计值或技能。

第二个方式就是游戏物件间的非传递关系,更通俗的说法是石头剪刀布关系。在这种情况下,成本和利益也许没有直接关系,但游戏物件本身存在联系:有些物件本身优于其他物件,但依然比某些物件略低一等。游戏“石头剪子布”就是典型例子;三种出法都没绝对优势,因为每种出法都具有平衡关系,打败其他出法但又输给第三种出法。

剪刀石头布 from wangluohongren.wangluoliuxing.com

剪刀石头布 from wangluohongren.wangluoliuxing.com

这点也体现在某些策略游戏中。在很多即时策略游戏中,各道具间都存在某种非传递关系。例如,常见情况就是步兵比弓箭手强,弓箭手比飞行员强,飞行员比步兵强。游戏的很大部分内容都是对照对手设定道具位置。

注意就如前个例子所述,传递性和非传递性关系能够结合起来。在典型即时策略游戏中,道具具有不同成本,所以脆弱弓箭手依然会被强劲飞行物打败。同类道具存在传递关系,但不同类道具则存在非传递关系。

非传递关系能够通过矩阵和基本线性代数解决。例如,剪刀石头布的解决方案是你设想每种出法的比例与对方相当:那就会出现1:1:1。现在假设你稍微修改游戏,凭借石头胜出能够得到3分,凭借布胜出能够得到2分,凭借剪刀胜出能够得到1分。现在的预期比例是多少?若你希望玩家按一定比例运用某道具,平衡性良好的非传递关系就是很好保障。

第三种平衡游戏物件的关系是让所有物件别具一格,能够进行直接比较。由于物件间无法进行正式数值比较,唯一的平衡方式就是进行额外测试。

这三种方式都存在某些联系。传递关系主要依靠设计师找到正确成本曲线。若你计算错误,游戏的所有物件都会出错;若你发现某块内容缺乏平衡性,你就需要调整所有内容。测试完再创建传递关系要比提早设计简单得多。由于很多东西依赖于正确计算,我们通常要进行反复试验,因此会消耗很多时间。

非传递关系需要解决非常棘手的算术问题。另一缺点就是需要谨慎行事,否则就会给人翻版剪刀石头布的感觉(游戏邦注:这会让玩家丧失兴趣)——很多人觉得非传递关系不过就是猜谜游戏,所有决定都不是基于策略而是靠运气和随机性。

“奇特”关系很难进行平衡,因为在这里你无法运用原本能够实现此目标的工具——数学运算。

3种常见游戏平衡技巧

通常我们能够通过3种方式平衡游戏:

* 运用数学运算。在游戏中创造传递或非传递关系,确保所有内容同成本匹配。

* 运用设计师直觉。调整游戏平衡性直到你“感觉不错”。

* 运用游戏测试。基于测试结果调整游戏(在测试中,老练玩家根据指示在游戏中探索,争取获胜)。

这些方式都有相关挑战性:

* 数学运算很难,而且会出现失误。若公式错误,所有游戏内容都会发生偏离,这不利于快速建模。某些奇特游戏技能或物件若过于罕见也许就无法进行数学运算,需要利用其他平衡方式。

* 直觉常出现人为误差。这并不绝对;不同设计师对于游戏的最佳设计会有不同看法。这在大团队项目中尤其危险,其中某位设计师也许会在项目中离开,而另一设计师不知如何接手。

* 游戏测试取决于测试者的质量。测试者无法发现游戏中的所有平衡问题;某些问题会沉寂几个月或几年都未被发现。更糟的是,有些测试者会有意不向你展示某些规则利用技巧,因为他们计划在游戏发行后将此运用于游戏体验中。

设计师要怎么做?尽自己所能,把握所有平衡技巧的利弊。作为游戏玩家,下次你碰到平衡性糟糕的游戏时,请体谅设计师要做到尽善尽美绝非易事。

更多游戏平衡技巧

下面是若干建议。

把握游戏的不同物件和机制及它们之间的关系。当然你应该在游戏设计初期就完成这些任务,但当你开始锁定细节内容时你很容易就会忘记把握大局。当你打算调整游戏内容时,有两点需要注意:

1. 游戏的美学核心是什么?此调整是否能够支撑核心?

2. 着眼机制的相互关联性。若你调整某内容,需知晓其他内容也会受到影响。独立游戏元素鲜少出现在真空状态,调整某要素通常会带来涟漪效应。通过把握机制和物件间的关系,我们很容易预测机制调整的二级影响。

每次进行一个调整。我们之前就谈到这点,但这需要忍受重复性。若做出调整后某内容出现中断,你就无法获悉这是由哪次调整所引起的。

学会运用Excel。你可以采用任何电子表格程序,但微软的Excel无疑在游戏设计师中颇受欢迎。当我称电子表格在游戏设计中非常重要时,很多人都觉得我有些不可思议。下面是些电子表格的应用体现:

* Excel让我们得以轻松记录和组织内容。罗列所有游戏物件和统计数据。就角色扮演游戏来说,罗列所有武器、道具和怪兽;就桌面战争游戏而言,罗列所有道具及其统计数据。任何你将在指南参照图表中找到的内容也许最初都是在设计师的Excel表格中诞生。

* Excel非常适合记录任务和数据,这对包含众多机制和部件的复杂游戏来说作用很大。若你看到桌上布满涉及大量怪兽及其相关数据的文稿,其中也许还记录怪兽的美工制作是否完成,怪兽数据是否已进行平衡或测试。

* 电子表格有助于搜集和编辑游戏数据。在各玩家拥有众多数据的运动游戏中,是否所有团队都具有平衡性?合计或平均各队的所有数据,你就能够把握各团队的优缺点。在融入传递关系的游戏中,是否所有游戏物件都具有平衡性?在电子表格中合计所有成本和利益。

* 你可以通过电子表格运算模拟数据。通过生成随机数据,我们就能够获悉此类信息:一定范围物件的破坏频率,从而把握总体范围和结果分布。

* 电子表格能够帮你查看游戏调整的因果关系。通过基于特定你希望调整的数值创造公式, 你就能够调整某数值,然后查看其他相关数值会发生什么变化。例如,若你制作的是大型多人在线RPG,你就能够通过Excel计算武器每秒带来的破坏性,然后立即获悉调整基础破坏、准确性或攻击速度将产生的变化。

运用“翻倍规则”。假设你知道游戏有某些数值过高,但你不知道此数值是多少。也许只是有些过高,或者有些不妥。无论是哪种情况,将其减半。同样,若你知道某数值过低,无论低多少,将其翻倍。若你不是100%确定正确价值所在,将其翻倍或减半。

从表面数值来看,这听起来有些荒谬。若宝石成本的偏低程度只是10-20%,翻倍的激烈举措将产生什么影响?在实际操作中,其可行性体现在如下几方面。首先,你也许认为这只是稍微偏离,完全错误;若你只进行微调,而数值需要翻倍,这需要你不断重复方能到达你原本需要达到的标准。

但翻倍规则存在一个更突出的优点。游戏设计是个发现过程。实际情况是,你并不知道平衡游戏的正确数值;若你知道,游戏早已得到平衡。若某游戏数值发生偏离,你就需要找到正确数值,所采用的方式是调整数值,然后查看所出现的情况。通过进行大幅度调整,你就会看到此数值给游戏带来的影响(游戏邦注:也许这只需要小幅调整,但通过翻倍或减半某数值,你将更深入了解自己的游戏)。

有时你会发现较大幅度调整游戏能够以预想不到的方式改变游戏机制,但此变化会让设计变得更杰出。

平衡首回合的优势。尤其在回合游戏中,玩家在开始时存在某细微优势(或劣势)的情况非常普遍。情况并非总是如此,但当出现暗此种情况时,你可以通过系列常见技巧进行弥补:

* 替换初始玩家。例如在4人游戏中,你应在每个完整回合后将下回合的初始玩家替换为左边的用户。这样此回合优先的玩家就会在下回合最后开始。

* 给予劣势玩家额外资源。例如若游戏目标是在游戏结束时争取获得最高分,那么你要让玩家以不同积分开始游戏,让最后进行的玩家获得额外积分补偿。

* 降低发起玩家初期回合的效率。在纸牌游戏中,玩家通常在轮到自己时出4张牌。你可以进行调整,让初始玩家出一张牌,下位玩家出两张牌等,直到所有玩家都出4张牌。

* 对于非常简短的游戏,不妨设置系列游戏回合,让所有玩家都有优先机会。这在纸牌游戏中很常见,其中完整游戏体验通常经由多人之手。

在学习规则时将其写下。设计游戏的过程中总是会有成败。你将从二者中学到东西。当你发现游戏设计“法则”或新游戏平衡技巧时,将其记下,定期翻看笔记。遗憾的是,鲜有设计师能够真正做到这点;因此,他们无法将自己的经验传递给其他设计师,他们有时会在许多作品中犯相同错误,因为他们忘记早前得到的教训。

平衡角色

在早前的设计师生涯中,我非常着迷于游戏平衡。“有趣游戏即平衡游戏,平衡游戏即有趣游戏”是我的真言。我知道我常因不满作品缺乏平衡性,建议即时进行修复而惹恼众多前辈。

虽然我依然认为平衡性非常重要,是游戏设计师不可或缺的技能,但我现在的态度要温和许多,我知道有些作品虽然缺乏平衡性但依然非常有趣。我也发现有些作品之所以非常有趣是因为它们故意融入不平衡因素。而且有些作品虽然极度缺乏平衡性但依然在市场中表现突出。这些都是罕见情况。但需注意的是本文所谈及的观点还是要以遵循游戏终极设计目标为前提。这些技巧只是你的工具,而非主宰因素。(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

Level 16: Game Balance

When veteran gamers or game designers are playing a game, if they are doing too well or too poorly, they will often comment on the game’s balance. This word is important, but I fear it is often overused. Like the word “fun,” there are different kinds of balance, and understanding what game balance is and why it’s important is what we cover today.

Why are we only covering this now and not earlier (like, say, at the start of the Design Project)? As mentioned earlier, balancing the game is something that is best left until after you have a good set of core mechanics. Balancing a game that is simply not meeting its design goals is a waste of time, and when you change the core mechanics you’ll just have to balance the game again. So here we are, with a work-in-progress that has survived multiple rounds of playtesting, and it is time to take it to the next level.

What is Game Balance?

In a two-player game, saying it is “balanced” usually means that one player does not have an unfair advantage over the other. But we also hear the term used in relation to single-player games, where there is no opponent other than the game itself, and any “unfair advantage” the game may have could just be considered a challenge. And then we may talk of individual cards in a game like Magic: the Gathering as being “balanced” even when all players have access to that card, so it does not give an advantage to any individual. What’s going on here?

In my experience, when we talk of “game balance” we are generally talking about one of four things. Context usually makes it clear which one we are talking about:

1. In single-player games, we use “balance” to describe whether the challenge level is appropriate to the audience;

2. In multi-player games where there is asymmetry (that is, where players do not start with exactly equal positions and resources), we use “balance” to describe whether one starting position is easier to win with than another.

3. Within a game, if there are multiple strategies or paths to victory that can be followed within the game, we use “balance” to describe whether following one strategy is better or worse than following another.

4. Within a system that has several similar game objects (such as cards in a trading-card game, weapons in a role-playing game, and so on), we use “balance” to describe the objects themselves, specifically whether different objects have the same cost/benefit ratio.

Let us examine each of these more closely, and then we will go over some practical techniques for balancing your game.

Balance in Single-Player Games

In single-player games, we use “balance” to describe whether the challenge level is appropriate to the audience.

Note that, by simply playing the game and getting experience with it, your audience will eventually become more skilled at the game. This is one reason why the later levels of video games are usually harder than the earlier levels. (Recall that another reason is so that the gameplay matches the dramatic tension in the narrative.) The change in difficulty over time in a single game has a name: we call it pacing.

There is one obvious problem here that we face as game designers: how do we know what an “appropriate” challenge level is? Sure, we can say that a logic/puzzle game for adults is probably going to be harder than a similar game for young children, but beyond that… how are we supposed to know what is too easy or too hard? The obvious answer: playtest!

There is another problem, however: not all players are exactly the same. Even within a narrow target audience, players fall along a bell curve, with a few that will be highly skilled and a few that are the opposite. In your playtests, how do you know where your testers fall on that bell curve? If you are just starting out, the ideal thing to do is to use lots and lots of playtesters. When you have dozens or hundreds of people giving feedback on your game, you can get a pretty good idea of what the overall ranges are. As you gain experience as a game designer, you will get a better feel for your audience, and you will need progressively fewer and fewer playtesters to give you the same good results. (If you’re starting out but you don’t have the time or resources to do lots of playtests, you can sometimes fake it if you have some idea of where your own playtesters fall on the curve. Do they consider themselves above-average or below-average skill level, compared to the other kinds of people you’re making your game for?)

Even if you have a pretty good idea of how to modify the difficulty of your game and where your target audience falls, what do you choose as your challenge level when the audience is diverse? No matter what you do, your game will be too hard for some people and too easy for others, so this appears to be a no-win situation. If you must choose a single level of challenge, a rule of thumb is to aim for the middle of the curve, as you will get the most people (the widest possible audience) that way. Another way around this is to provide support for those at the ends of the curve, using multiple difficulty levels, handicaps, or alternate rule sets to make things easier or harder.

Balance in Asymmetric Games

In multi-player games where there is asymmetry (that is, where players do not start with exactly equal positions and resources), we use “balance” to describe whether one starting position is easier to win with than another.

Truly symmetric games are rare. We think of classic games like Chess and Go as symmetric, since each player starts with the same set of pieces and plays by the same rules, but there is one asymmetry: one player goes first! If you modify Chess so that both players secretly write a move on a piece of paper and then the moves are performed simultaneously, it becomes fully symmetric (and plays very differently).

This brings up an interesting question: if your game is symmetric, do you need to worry about game balance at all? After all, both players start with exactly identical resources and starting positions and so on, so by definition no player can have an unfair advantage. This is true, but the designer must still consider other types of balance, particularly whether there is a dominant strategy. Simply making all players equal does not get you off the hook.

Even if your game is asymmetric, why bother balancing it? The simple answer is that it is a typical player expectation that a game will not give an automatic advantage or disadvantage to certain players, other things being equal. (You can play around with this. The card game The Great Dalmutti, for example, intentionally casts players in unequal roles as a way of showing how life isn’t fair; but that is part of the game, and the instructions and mechanics go to great lengths to set player expectations accordingly. But if your game is not breaking this rule with specific intent, you should be thinking about how to make it as balanced as possible.)

Asymmetric games are, naturally, harder to balance. The more asymmetric, the more carefully the game must be playtested carefully. One of the easiest ways to confirm this kind of balance is to find ways of relating each players’ resources to one another. If you determine that in gameplay, one Apple is always worth exactly two Oranges, then a player who starts the game with an Apple will be balanced against a player starting with two Oranges.

Sometimes, players are so different that direct comparisons are impossible. Some games not only give players different starting resources and positions, but also different rules to play by. Some players may have exclusive access to certain resources or abilities. One common asymmetry in games is to give players different and conflicting objectives (for example, one team’s objective is to survive for some number of turns and the other team’s objective is to eliminate the first team before that many turns). The more difficult it is to make direct comparisons between players, the more you will have to playtest to compensate.

Balance between Strategies in a Game

Within a game, if there are multiple strategies or paths to victory that can be followed within the game, we use “balance” to describe whether following one strategy is better or worse than following another.

One might wonder, why bother with this? If a game allows for multiple strategies but one is more powerful than the others, doesn’t exploiting the best strategy just equate to players trying to win? As long as no individual player has an unfair advantage, isn’t it okay for your game to simply be “whoever finds the most powerful strategy wins”?

The problem here is that, once a dominant strategy is discovered, astute players will ignore all suboptimal strategies. Everything in the game that is not part of the dominant strategy becomes extraneous noise. There is nothing inherently wrong with a game that has a single winning strategy, but in this case the suboptimal ones should be removed to make the game more streamlined. If you include options for players that are suboptimal, these become false decisions, because really there is only one decision (follow the dominant strategy).

If it is worth including several potential winning strategies in a game, then, it becomes much more interesting if those strategies are balanced. Again, much of this comes down to playtesting. In this case, when players are playing your game, make note of whether certain strategies seem to be used more often than others, and which ones seem to win. If several items are available for players to purchase in a game, is there one that seems to always get bought early, while others seem to be used rarely if ever? If players have a choice of actions each turn, does the winner of each playtest always seem to be the one that chose one particular action more often than everyone else?

Playtesting alone is not automatic proof that a particular strategy is unbalanced, but it should give you strong signals that certain aspects of the game need closer inspection. Sometimes, players will use a particular strategy because it is the most obvious or the easiest and not because it is the most optimal. Some players will avoid anything that seems too complicated or requires finesse, even if it is ultimately better in the long run.

Balance Between Game Objects

Within a system that has several similar game objects (such as cards in a trading-card game, weapons in a role-playing game, and so on), we use “balance” to describe the objects themselves, specifically whether different objects have the same cost/benefit ratio.

This kind of balance is specific to games that give players a choice between different game objects. Some examples:

* Cards in a trading-card game. Players build a deck with a set number of cards from their collections. The choice of which cards to add is one of the key factors in the game’s outcome, and designers try to make the cards balanced with one another.

* Units in some war games and real-time strategy games. Players have the ability to purchase units during play, and different kinds of units may have different abilities, movement rates and combat strengths. The designer will try to make the units balanced with one another.

* Weapons, items, magic spells, etc. in a role-playing game, either tabletop or computer/console. Players may purchase any of these for use in combat, and they have different costs and different stats and abilities. The designer will try to make these objects balanced with each other.

In all of these cases, there are two goals. The first is to prevent any game object from being so weak that it is useless in comparison with other objects. This again becomes a false choice for the player, because they might be able to gain or purchase a certain object but they will quickly find that it is not worth using; the object is therefore a waste of the player’s (and designer’s) time.

The second goal is to prevent a game object from being too powerful. Any single game object that becomes a dominant strategy makes all other objects in the game useless in comparison. In general, if you absolutely must choose between making an object too weak or too powerful, err on the side of making it too weak.

Two objects are balanced if they have the same cost/benefit ratio. That is, what you give up to gain access to an object (this includes explicit costs like in-game money or resources, and also opportunity costs like drawbacks, limitations, or exceptions to the object’s capabilities) should be in some proportion to the in-game benefits you get from the object. The costs and benefits do not have to be exactly the same (in fact, usually the benefits are greater, or else you would simply ignore the object). However, when comparing two different objects, the proportion of costs to benefits should be roughly the same for each.

Three Ways to Balance Game Objects: Transitive, Intransitive, and Fruity

I have encountered three general methods for balancing game objects. The first is technically referred to as a transitive relationship. In more colloquial (but still geeky) circles, it is called a cost curve. This is the most direct way to balance objects. The general idea is to find some desired proportion of costs to benefits. This may be a linear proportion (something twice as costly is exactly twice as powerful) or it may be curved in some way (perhaps there is a law of diminishing returns, where you have to pay progressively more for each additional bit of benefit; or perhaps there are increasing returns, where you essentially get a “bulk discount” for paying a lot at once). It all depends on your particular game, but playtesting, experimentation and instinct will help you to figure out what kind of relationship there should be.

The next step is to reduce every cost and every benefit to a single number that can be compared. Take all the costs of an object and add them together; also sum the benefits. Compare the two, and see if the object is giving the correct numerical benefit for the cost.

This method is often used in trading-card games. If the game has an established cost curve, it makes it much easier to create new cards with combinations of existing effects. In Magic: the Gathering, if you want to create a new creature with a given color, power, toughness, and set of standard abilities (say, a White 4/3 with Flying and First Strike), there are already several costs it can be, and designers working on this game (and sufficiently informed players) could tell you exactly what those equivalent costs are. Adding more abilities comes with an increase in cost, and decreasing the cost would necessitate a removal of stats or abilities.

The second method is an intransitive relationship between game objects, better known as a rock-paper-scissors relationship. In this case, there may not be a direct relationship between costs and benefits, but there is a relationship between the game objects themselves: some objects are inherently superior to others and inferior to still others. The game Rock-Paper-Scissors is the canonical example; none of the three throws is dominant, because each throw will draw with itself, beat one of the other throws and lose to the third one.

This can be seen in some strategy games as well. In many real-time strategy games, there is some kind of intransitive relationship between units. For example, one common relationship is that infantry are strong against archers, archers are strong against flying units, and fliers are strong against infantry. Part of the game is managing your particular allocation and positioning of units (in real time) in comparison to your opponent.

Note that transitive and intransitive relationships can be combined, as in the previous example. In typical real-time strategy games, units also have different costs, so a weak (but cheap) archer may still be defeated by a strong (and expensive) flying unit. Within a single class of units, there may be transitive relationships, but the different classes have intransitive relationships with one another.

Intransitive relationships can actually be solved, using matrices and some basic linear algebra. For example, the solution to rock-paper-scissors is that you expect the proportion of each throw to be equal to the others: there should be a 1:1:1 ratio. Now, suppose you modify the game slightly, so that each win with Rock scores 3 points, a win with Paper scores 2 points, and a win with Scissors scores 1 point. What is the expected ratio now? (It turns out the ratio is not what you’d expect; with optimal play on both sides, you would see 1 Rock for every 3 Paper and every 2 Scissors. The math required to do this is outside the scope of this course.) If you are looking for players to use objects in a certain proportion (with some being more commonly used than others), a well-balanced intransitive relationship is a good way to guarantee this.

A third method of balancing game objects is to make each one so different and unique from the others, that direct comparisons are impossible. (I call this “fruity” in the sense that the designer, and later the players, can only compare apples to oranges.) Since formal and numerical comparisons between objects cannot work, the only way to balance this is through excessive playtesting.

There are challenges associated with all three of these methods. For transitive relationships, everything relies on the designer finding the correct cost curve. If your math is wrong, it will be wrong for every object in the game; if you find one thing that is unbalanced, you’ll probably have to change everything. Transitive relationships are much easier to develop in retrospect after playtesting, than developing them ahead of time. Since so much relies on getting the math right, it also tends to take a lot of trial-and-error and therefore a lot of time.

Intransitive relationships, as noted above, take some tricky math to solve. Another drawback is that, unless done very carefully, their presence can make the entire game feel like glorified Rock-Paper-Scissors, which some players find to be a turnoff – many have the perception that intransitive relationships are nothing but guessing games, where every decision is based not on strategy but on luck and randomness. (A full discussion of whether this is or is not the case is also outside the scope of this course.)

“Fruity” relationships are really hard to balance, because one of the most important tools in doing so – mathematics – is no longer available.

Three General Game Balance Techniques

In general, there are three ways to balance games:

* Use math. Create transitive or intransitive relationships in your game, and make sure that everything is in line with the cost.

* Use your instincts as a game designer. Change the balance in the game until it “feels right” to you.

* Use playtesting. Adjust the game based on the results of playtests, where the players are experienced gamers who have been instructed to play to exploit and win.

There are challenges with each of these ways:

* Math is hard, and it can be incorrect. If your formulas are wrong, everything in the game may be off a little bit, which is inconvenient for rapid prototypes. Some really strange abilities or game objects may not have any math to them if they are too unique, requiring other ways of balancing.

* Instinct is vulnerable to human error. It is also not absolute or reproducible; different designers may disagree on what is best for the game. This is particularly dangerous on large team projects, where one designer may leave in mid-project and another cannot take over (or rather, they can, but they will not be able to finish the game in the same way that the original designer would have).

* Playtesting relies on the quality of your testers. Testers may not find every balance issue with the game; some problems will go undiscovered for months or years (even after public release of the game). Worse, some testers may intentionally avoid showing you rules exploits, because they plan to use them after the game is released!

What is a designer to do? Do the best you can, and understand both the strengths and limitations of the balance techniques that you are using. And as a game player, the next time you run into a game that seems horribly unbalanced, have some appreciation for how difficult it can be to get things perfect.

More Game Balance Techniques

Here are a few other random bits of advice I’ve picked up, in no particular order.

Be aware of the different objects and systems in your game and their relationships. You should already have done this during your initial design of the game, of course, but it is easy to forget the big picture when you start focusing on small details. There are two things in particular that you should return to first, whenever you make changes to your game:

1. What is the core aesthetic of your game? Does this change support the core?

2. Look at the interconnections between systems. If you change one thing, you should know what other things will be affected. Individual game elements rarely exist in a vacuum, and changing one thing can have ripple effects throughout the game. By being aware of the relationships between systems and objects, it becomes easier to predict the second-order effects of a mechanics change.

Make one change at a time. We’ve said this before, but it bears repeating. If something breaks after making a change, you know exactly why. If something breaks after making ten changes, you don’t know which change (or combination of changes) caused it.

Learn to love Excel. It can be any computer spreadsheet program, though Microsoft Excel is the most popular among game designers. Often, students look at me like I’m crazy when I suggest that a spreadsheet is useful in game design. (Like, aren’t those things only used by corporate finance dudes or something?) Here are some examples of how spreadsheets are used:

* Excel makes it easy to keep lists of things and organize them. List all of your game objects and their stats. In a role-playing game, list all weapons, items and monsters; in a tabletop war game, list all units and their stats. Anything that you’d find in a reference chart in the instructions (or a strategy guide) probably started off its life in a designer’s Excel sheet.

* Excel is great for keeping track of tasks and status, which is useful for a complicated game with lots of systems and components. If you’ve got a table with a couple hundred monsters and all their stats, it might also have an entry for whether the art for that monster is done, or whether the stats for that monster have been balanced or playtested yet.

* Spreadsheets are good for collecting and manipulating statistics in your game. In a sports game where each player has a list of stats, are all of the teams balanced with one another? Sum or average all of the stats on the team, and you can get some idea of the overall strengths and weaknesses of each team. In a game with transitive relationships, is each game object balanced? Add up the costs and benefits in a spreadsheet.

* You can use spreadsheets to run statistical simulations. By generating random numbers (in Excel you can use the RAND() function and press F9 to reroll), you can generate random die-rolls for things like damage within a range, many times, to see the overall range and distribution of outcomes. (Statisticians call this a “Monte Carlo” simulation, in case you were wondering.)

* Spreadsheets help you to see causes and effects of changes in the game. By creating formulas based on specific values that you want to change, you can change one value and see what happens to the other values that depend on that one. For example, if you’re working on a Massively-Multiplayer Online RPG, you could use Excel to compute the damage-per-second of a weapon and then instantly see how that changes when you modify the base damage, accuracy, or attack speed.

Use the Rule of 2. Suppose you have some number in your game that you know is too high, but you don’t know how much. Maybe it’s just a little bit too high, or maybe it’s quite a bit off. In either case, cut it in half. Likewise, if you have a value that you know is too low, regardless of how much too low it is, double it. If you aren’t 100% sure of what the correct value is, double it or cut it in half. This is the “Rule of 2.”

At face value, this sounds rather ridiculous. If the cost of a gemstone is only 10 to 20 percent too low, what could be gained by taking the drastic measure of doubling it? In practice, there are some reasons why this works. First, you might think that it’s only slightly off, and you might be wrong; if you only make minor adjustments and the value really did need to be doubled, it will take you much iteration to get to where you needed to be in the first place.

There is a more powerful force at work, though, when applying the Rule of 2. Game design is a process of discovery. The fact is, you don’t know what the correct numbers are to balance your game; if you did, the game would be balanced already! If one of the values in your game is off, you need to discover what the correct value is, and you do this by changing the value and seeing what happens. By making a major adjustment, you will learn a great deal about the effect of this value on the game. Maybe it did only need a minor adjustment, but by doubling or halving the value, you will learn so much more about your game.

Occasionally, you will also find that by making such a large change to your game, it changes the dynamics in a way that was unexpected but (accidentally) superior to your original design.

Balancing the first-turn advantage. In turn-based games in particular, it is common for there to be a very slight advantage (or disadvantage) to going first. This is not always the case, but when it is, there are a few common techniques for compensating:

* Rotate who the first player is. In a four-player game, for example, after each complete round (where every player has a turn), rotate the starting player to the left for the next round. In this way, the player who goes first on this round will go last on the next round. (When I was growing up, my game group used a pencil to mark the first player, so we dubbed this the “Pencil of Power” technique.)

* Give the disadvantaged players some extra resources. For example, if the objective of the game is to score the most points by the end of the game, give each player a different number of points to start the game, with the last player having slightly more points to compensate for the disadvantage of going last.

* Reduce the effectiveness of early turns for the first players. In a card game, maybe players typically draw four cards at the start of their turn. You could modify this so that the first player only gets to draw one card, the next player draws two, and so on until all players are drawing four.

* For very short games, play a series of games where each player gets to go first once. This is common with card games, where a complete game is played in a series of hands.

Write down your own rules as you learn them. As you design games, you will have successes and mistakes. You will learn from both (especially your mistakes). When you find a “law” of game design or a new game balance technique, record it and review your notes periodically. Tragically, very few designers actually do this; as a result, they cannot pass on their experience to other designers, and they sometimes end up making the same mistakes on multiple games because they forget the lessons learned from earlier ones.

The Role of Balance

In my early days as a designer, I was very passionate about game balance. “A fun game is a balanced game, and a balanced game is a fun game” was my mantra. I’m sure I annoyed many of my seniors with my rantings on the imbalances in our games and why we needed to fix them immediately. Such is the privilege of youth.

While I still believe balance is important and a key skill for any game designer, I now take a more moderate line. I have seen some games that are fun in spite of being unbalanced. I’ve seen other games that are fun specifically because they are intentionally unbalanced. I have seen some games that have done astoundingly well in the marketplace, despite having egregious imbalances. These are rare and special cases, to be sure. But let this serve as a reminder to you that the techniques and concepts discussed today should never take priority over the ultimate design goals for your game. Let these techniques be your tools, not your master.(Source:gamedesignconcepts


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