作者：Eric Schwarz

我们经常讨论游戏的难度，比如是否太难？哪部分会让玩家感到麻烦？是否过于容易从而显得乏味无趣？但是我们很少将注意力放在难度的不同基本类型上，正是这种种难度铸就了我们的游戏体验，让我们对游戏所提供的挑战有一定的认识。在这篇文章中，我想列举某些最基本的难度类型以及与这些难度类型的执行等相关问题。阐述游戏中重要的不仅仅是那些挑战，挑战的本质也同样重要。

反复尝试寻找解决方法

游戏中最显而易见的难度类型就是反复尝试以寻找解决方法，这也是目前最为普遍使用的类型。简单地说，这种反复尝试贯穿在玩家开展任务的过程中，通过实验（游戏邦注：比如“没有其他的路可以走了，或许我可以试试这条路”）或建议（游戏邦注：“这些是你要执行的命令，士兵们，马上前往执行吧！”）的形式。至少从理论上来说，这种方式为玩家呈现的主要难度是挑战的程度（游戏邦注：比如敌人的类型和数量）往往会略高于玩家感到舒适的程度，也就是说玩家必须得到提升才能够克服挑战，这种提升包括尝试新的战术、冒着更大的风险做事和拥有强大的意志力或运气等。

正如我们中许多人已经证实的那样，反复尝试这种难度类型有着明显的两极分界线。通常来说，过多的失败会让玩家产生挫败感，但是过多的成功又会让玩家觉得好像游戏对他们而言不够难。除了基本的平衡性之外，这种难度的主要问题在于，难度对不同玩家有着不同的门槛。休闲玩家只是想要享受游戏的故事性，他们并不喜欢游戏中会出现猝不及防的死亡。然而，硬核玩家更为喜欢那些“疯狂的”场景，他们希望每个回合都能够面对挑战，依靠自己的努力去取得每个胜利。最后，开发者便会陷入如下情形：他们要平衡的是同一款游戏中的3或4个愿景，因为不同玩家对游戏难度的需求不同。

当然，步调也是难度衰退和流动中主要关注的东西，通常也是反复尝试的本质。玩家需要游戏中含有各个步调不同的部分，这些部分之间切换迅速而且不会产生过多的问题，比如游戏中让人觉得不具挑战性的战斗和紧张的游戏体验交替出现。在考虑不同的游戏玩法偏好时，将这些构建到游戏中是个很困难的过程。毕竟，虽然平衡游戏中的某个事件并给予玩家他们希望获得的体验较为简单，但是在整个游戏背景之下实现这个目标与前者完全不同。

有适应力的难度设置是种可以解决这个问题的方法。在最基础的层面上，通常的做法是改变提供给玩家的资源（游戏邦注：如生命值和弹药等）数量，或者根据玩家的行为来协调强大和弱小道具的出现频率（游戏邦注：比如玩家在困难环境中会拾到更多“生命值全满”的道具）。这种功能在游戏中极为普遍，原因或许是开发者不愿意去设计不同的难度等级（游戏邦注：作者认为这不是个好想法），或许是因为玩家总有好奇的想法，会选择并不适合他们的难度等级（游戏邦注：每个玩家对“普通”难度等级的理解都各不相同）。

半条命2(from orange.half-life2.com)

可适应性难度既可以清晰明显，也可以隐藏起来。比如，《Prey》将可适应性难度选项添加到游戏的选项界面中，这样玩家可以根据自己的偏好决定是否启用。而《半条命2》在提供三种不同的难度等级（游戏邦注：简单、普通和困难）的同时，还设置了一层可以用来分析玩家在游戏中的行为过程、资源层次和某些事件完成的简易程度等方面的代码，随后游戏会调整敌人掉落的道具和打破箱子后获得的资源数量等，确保玩家总是能使用数量刚好的生命值和弹药完成遭遇战，但是在此过程中资源的数量又不会让玩家觉得自己完全是安全的或者让玩家的武器装满弹药。有些游戏以更微妙的方式执行这种设计方法，比如在玩家濒临死亡时让其更快地击败BOSS，创造出一种动态的紧张感。

对我而言，可适应性难度可能产生的最大问题是，当作为内置功能添加到游戏中且不可关闭时，玩家就对游戏失去了控制力。尽管我时常从那些单纯为了提升难度而设计得较为困难的游戏中获得极好的体验，但是我完全理解某些玩家并不希望自己希望获得的东西掌控在别人手上。而且，可适应性难度还能够让人产生可预测和内容贫乏的感觉，遭遇战就失去了人为制造的感觉（游戏邦注：人们对《上古卷轴4：湮灭》的批评主要是这个方面）。这样看来，我认为可适应性难度最好的设置就是像《Prey》那样，做成选项菜单中的可选项或者只在某个难度等级中使用这项设置，在最高难度的模式中去除所有的帮助，这会使上述问题得到缓和，让玩家对自己所选取的难度有更为合理的理解（游戏邦注：比如玩家会产生“我选择了最困难的模式，我应该知道这个模式对我来说过于困难”的想法）。

忍耐和消耗

另一种测试玩家的方式着眼于长期而不是短期。从最基本的层面上来说，所有形式的忍耐都围绕资源管理来开展，玩家被给予数量有限的有价值或重要道具，其分配的控制极为精细。在所有游戏中，资源的控制主要通过以下三种方法：

1、“随机”掉落。惯常用法是敌人被打败时会掉落贵重物品，或者玩家打开箱子获得补给品等。根据难度、玩家在游戏中的经历、玩家已经拥有的资源数量、玩家的能力、角色等级、队友数量来控制补给，这样就可以精确地调控游戏的难度，从而提供某种挑战。

2、消耗率。在不同的游戏中，玩家消耗补给的速度也大不相同。比如，在射击类游戏中，战胜较为困难的BOSS或许无需耗费过多的弹药，但是可能需要消耗大量的生命值。相反，在面对大量较小的敌人时，玩家可能需要消耗大量的弹药，但是生命值却不会大幅下降。学会预测玩家继续游戏所需的东西很重要。如果游戏使用的是可适应性难度系统，这或许并不是个大问题，但是即便如此，细致考虑玩家消耗某些资源的速度也会改善遭遇战设计，使得游戏显得更为鲜活，并且能够满足玩家的娱乐需求。战略性地消除某些资源与战略性地提供资源同样重要，因为这可以构建起紧张感，调控玩家进程的步调。

3、玩家的智慧。这种方法较常用于角色扮演类游戏中，聪明的玩家通常会在面对困难的遭遇战之前先期购买药物和弹药等有用的道具。玩家在野外逗留的时间很大程度上受玩家自身的行为影响，以及玩家在购买补给后外出所遇到的事件。游戏很难对这个方面进行控制，坦诚地说，也不应当对其进行控制。应当关注的是玩家能够和不能够做什么事情，然后围绕这个方面来构建挑战，比如负重和疲劳系统，这会轻微限制玩家能够携带的道具数量。但是，强制使用不合理的硬性限制（游戏邦注：比如规定玩家每次最多只能携带3个生命药剂）并非合适的管理方法。

长期消耗可能对许多游戏并不适用，但是以不同的方式来审视消耗可能揭露处某些游戏机制中的有趣成分，或许之前并未察觉到。比如，《俄罗斯方块》之类的解谜游戏中有很强大的消耗元素，玩家的行为、难度等级和提供给玩家的方块会导致游戏界面中可用的空间逐渐减少。在此之上，游戏的速度也是玩家必须细心掌控的资源，因为在游戏过程中方块的掉落会越来越快。尽管没有生命值和弹药等内容，但是《俄罗斯方块》对空间和时间的掌控确实很独到。你应当意识到，消耗和忍耐可以应用的方面不仅仅是实物资源，这种设计会让现有的机制更有深度。

“伪造”难度

这种难度属于反复尝试难度的范畴内，我所说的“伪造难度”普遍存在于游戏行业中，但是颇为依赖游戏题材。伪造难度使用方式多种多样，但总结起来通常都是通过欺骗玩家或者扭曲游戏规则以达到产生挑战性的目的。无论玩家是否在意这些欺骗，这种设计通常都会让玩家产生极大的挫败感和愤怒。

伪造难度最为普遍的形式也可以归到可适应性难度类别，也就是说，通过改变游戏情形中的规则来向玩家提供更大的挑战，通常被称为“橡皮条选择”。关键的区别之处在于，可适应性难度偏向于玩家的喜好（游戏邦注：比如玩家在生命值较低时获取生命恢复道具的可能性提升50%），但是伪造难度更偏向敌人或玩家的对手。然而，因为敌人很少以公平的状态与玩家进行战斗，事实上还经常使用完全不同的规则，这意味着玩家的对手总是瞬间变成了超人，比如突破限制提升速度、攻击力暂时大幅提升、施展出原本无法克制玩家的技能等。

Mario Kart(from nintendo.com)

《Mario Kart》便是这种类型难度的绝佳例证，事实上，该系列作品正是因此而备受诟病。尽管游戏橡皮条选择的目标是为玩家提供紧张且令人兴奋的体验，确保每次竞速结束时对手都很接近玩家，但是对于那些更有经验的玩家而言，这种形式的难度带来的只有轻蔑。游戏所产生的错觉足以愚弄技能较差的玩家，因为这些效果都很微妙而且通常会迎合玩家的喜好，但是当同样的系统被应用到足以凌驾于高难度游戏之上的玩家身上时，为跟上玩家的速度，电脑就要被强迫做出令人难以置信的举动，比如使用无耻的作弊、获得比玩家更厉害的道具和能力甚至违反物理学原理。

还有种伪造难度的形式是不真实的挑战。在不真实挑战中，玩家通常被要求做出标准的行为——打败某些敌人或者在规定的时间内跑到终点等。但是，刚开始属于相对常规的任务迅速转变成对玩家反应和能力的测试，因为玩家会不断地被各种无法预测的障碍、陷阱和强大的敌人所困扰。关键在于，在所有这些情形中，玩家毫无防备，根本无法做充分的准备。通常，最后的结局是快速和令人沮丧的死亡，因为玩家认为自己即将取得成功而毫无防备。更为糟糕的是，通常克服这种类型挑战的唯一方法是再次尝试，时常都是从关卡的起点开始，玩家需要铭记前方隐藏的挑战。当这些挑战重重叠加时，最终可能导致玩家极为愤怒。

《侠盗猎车手》系列游戏在这个方面尤为突出。尽管游戏基于任务的架构暗示即将面对的挑战是独立且相对直观的，但是游戏中设置的难度很经常出乎玩家意料之外。以《侠盗猎车手：罪恶都市》为例，我经常提及的一个任务就是玩家需要在规定的时间内到达一连串的检查点。这不像是个很难的任务，不是吗？看起来似乎如此，但是事实上游戏设置其他的卡车等车辆会忽然出现在街道拐角处，如果玩家以全速通过，那么势必会撞上这些车辆，从而导致任务失败。玩家只有预先放慢速度让这些车辆先行通过，才有可能完成。这种情况并非只出现一次，在这次竞速任务过程中会出现5到6此，也就是说即便玩家的做法完全正确，游戏的设计仍然让玩家有失败的可能。《英雄本色》中也有同样的情况发生，敌人会精确地向玩家投掷手榴弹，如果没有经历过几乎不可能避开攻击。

坦诚地说，虽然伪造难度的形式多种多样，但是对玩家而言并不有趣，即便其是以最好的意图构建到游戏中。尽管如此设计的目标通常是为了提供无视玩家技能程度的不可预测或充满挑战的体验，但是往往产生的却是适得其反的效果。最糟糕的情况是，这有可能让玩家觉得游戏中的竞技不合常理，从而离开游戏。与多数难度形式不同的是，开发者应当避免使用这种类型的难度，除非你的目标是让玩家讨厌你的作品。

随机数值

尽管这种难度类型通常在战略和角色扮演游戏中使用，但是随机机制也出现在其他的游戏题材中，包括敌人在战斗中的行为、武器的影响范围和精准度等。

我偶尔会遇见某些被众人嘲笑的基于随机元素的机制，这些人声称此类设计将成功寄于不可预测的可能性而不是玩家技能之上。需要理解的关键之处在于，利用随机数值生成器来构建难度时，挑战并非被“运气”所替代。反而，难度的增加迫使玩家需要对那些完全无法预测的新情况拟定更为睿智的反应，重要的是整个过程的行动而不是个别行动。反复尝试通常测试的是玩家的反应和协调能力，但是构建于随机元素之上的系统测试的是玩家对改变做出响应和新情况的能力。

正如之前所提过的那样，随机元素会出现在所有类型的游戏中，无论这些游戏的难度来源于反复尝试、可能性掌控还是伪造难度。比如，在竞速模拟游戏中驾驶汽车，车辆的操作或者路况中总是有些随机的效果。如此设计并没有什么错，因为通常情况下玩家的技能足以应付任何情况下的随机元素。而且，随机并不一定意味着不可预测，它的意思只是游戏过程中可能出现某种程度的干扰，防止每次发生的事情都完全相同。否则，我们在玩《俄罗斯方块》时就会看到方块总是以同样的顺序重复出现，这就会让游戏显得乏味。

不幸的是，使用随机数值生成器构建系统很容易产生一个问题，尤其是在角色扮演游戏和战略游戏中，这个问题不在于机制本身，而在于玩家对机制的认知和理解。这种事情通常被称为赌徒的误解。最简单的例子便是抛硬币。尽管硬币正面或背面朝上的概率都是50%（游戏邦注：假定硬币按照合理的方法抛掷），但是我们仍然会想象这种相同的概率只适用于系列事件的结果，而不是单独的某个事件。换句话说，我们认为随着硬币一遍遍地被抛出，我们不会将硬币的抛掷当成某个独立的事件，而是看做整体事件的一部分。正因为此，我们也会认为之前的事件对将来可能发生的事件会造成影响。或者简单地说，硬币正面朝上的次数越多，我们就越认为下次抛掷背面朝上的概率会越大。

在游戏行业中，可以将这种情形套用到基于回合制的角色扮演游戏中。某技能使用成功的概率为70%，但是当我们发现技能连续数个回合失败之后就会产生挫败感，我们最终会因尝试改变这个问题而浪费时间和资源。究竟为什么会这样呢？我们可能会认为游戏机制篡改了数值！事实上，情况并非如此。玩家的想法时，由于技能成功的几率是70%，所以使用10次就应该会有7次成功。当然，情况并不一定会如此准确。每次使用技能成功的概率都是相同的，因而有可能出现上述连续数回合都失败的情况。

这个问题并没有简单的解决方案，因为你的对手不是数值，而是玩家的愿景。对于这个问题的解决，许多开发者采用的方式是制定度量，确保随机的概率更具预测性。比如，如果我设定技能的成功率是70%，那么我会在游戏中添加某个技能必定会击中的时间短，即便这在数学逻辑上根本与随机概念不符。情况确实如此，通常情况下，多数玩家会觉得他们所依赖的随机可能性完全不具有随机性，这种随机性被操控来满足玩家的愿景。而颇具讽刺意味的是，如果首先确保数学逻辑的正确性，那么玩家只会认识到游戏可能存在问题。很显然，这是个颇具争议的决定，或许并非所有人都能够认同这种做法，但是满足玩家的愿景总比让这些玩家因游戏不公平或者可能性不正确而产生挫败感要强。

展示是最重要的东西

这个章节的标题可能会引起某些人的愤怒，但是我觉得这个部分在游戏设计中并没有为人所关注，但是这却是需要学习的最重要的方面。就像我已经说过的那样，难度有着各种各样的形式，而且极具主观性。但是，重要的是还要认识到，将难度展示给玩家的方法同样很重要。如同赌徒的误解一般，有时出现问题的并非机制本身，而是玩家认知难度的方法出了偏差。

dead money(from blackcheezegaming.com)

让我们以近期发布的游戏《Dead Money》为例，这是《辐射：新维加斯》的最新可下载内容。游戏受到了玩家和媒体的攻击，他们认为其难度曲线并不合理。在《Dead Money》中，奴隶凌驾于《辐射》系列作品原本无尽的自由之上，玩家被爆炸物驱赶到某个非常特别而且几乎是线性的路径中，如果玩家过于深入人迹罕至的地区，就会不断遭到伤害。游戏中的许多挑战是摧毁不断播放爆炸声波的广播发射机，而这些东西通常隐藏在桌下、壁橱中和许多难以企及的地方。如此设计的目标在于为玩家创造出某种紧张感，玩家需要在自己被炸弹炸死之前迅速找到广播发射机。

从局外人的角度来看，可以很清晰地明白为何这个机制会让玩家产生挫败感。在即将爆炸时，炸弹线圈会产生某种高音调且持续的哔哔声，玩家需要迅速学会避开。还有个让玩家觉得特别卑微的是，他们被对手以这种方式奴役。其他使用这种设计的游戏通常会让玩家可以迅速地重获自由，尽管培养玩家对对手的怨恨是个很不错的做法，但是如果处理不当，这种怨恨反倒会转移到开发者自己头上。最后，这种强迫性的限制与多数玩家对新《辐射》游戏的愿景（游戏邦注：即开放性的角色扮演游戏，每个情形都可以有多种解决方案）相反。而在《Dead Money》，很多关卡只有唯一的解决方案，而这往往是玩家不喜欢的东西。

但是，《Dead Money》的问题并不在于机制本身。从基本层面进行分析，游戏的任务仅仅是玩家同时间赛跑，去移除环境中的威胁，即在角色被炸死之前关闭开关。就故事线路而言，爆炸循环机制固然很有效，但是本可以被许多相似的机制所替代，而且能够发挥同样的效能。更为重要的是，替换之后就不会像这样让玩家产生挫败感。比如，辐射和毒素威胁在《辐射》的世界中极为常见，那么，为何Obsidian不选择使用辐射的形式在表达同样的威胁呢？有趣的是，这种解决方式确实有在《Dead Money》中使用，但是使用的次数很少。用功能相似但较符合《辐射》设计方式的游戏机制来替代爆炸，我想抱怨游戏难度的人就会少得多，因为在这种情况下，玩家会认为挑战与《辐射》的游戏世界契合度更高，而且从整体上来说限制性更小。

看看周遭熟悉的游戏，我觉得你还会找到更多难度认知成为比难度本身更大问题的实例。我马上就能想出几个来，比如《杀出重围：人类革命》中BOSS不断发出的刺耳讥笑声给对玩家神经的挑战已经超过了BOSS战斗本身。事实上，当将角色与某种类型的难度联系起来时（游戏邦注：比如Boswer和《超级玛丽兄弟》中的城堡），如果角色令人烦恼或者当游戏机制本身并不有趣，就会迅速让玩家产生挫败感。

结论

尽管并不完整，但是这个分析应该会让大家了解不同类型的难度，并且理解为何人们在不同类型的游戏、不同场景和不同难度种类中会变得烦躁不安。创造和精致难度总是处在不断发展中，让所有的玩家都接受设计是件特别难的事情。即便如此，我也希望这篇文章能够让众开发者明白为何会出现这种情况，要在基础设计中采取何种步骤才能够确保游戏有趣且充满挑战性，同时避免让玩家产生挫败感。（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）

Understanding Difficulty

Eric Schwarz

Although we frequently have discussions about difficulty in games – is it too hard? which parts did you have trouble with? was it too easy and therefore boring? – we rarely direct our attention to the different fundamental types of difficulty which make up our experiences and colour our perceptions of the challenge a game provides. In this article, I’d like to go over a few of those most basic types of difficulty as well as the problems associated with implementing them, as well as bring out that it’s often not just the sheer challenge of a game that matters, but the nature of those challenges that matter.

Trial and Error

The first, and most obviously identifiable type of difficulty that we find in games, and by far the most common, is trial and error. Put simply, trial and error revolves around getting the player to perform a task, either through experimentation (i.e. “I don’t have anywhere to go, maybe I’ll try this”) or outward suggestion (i.e. “these are your orders, soldier, now move out!”). At least theoretically, the main difficulty this presents to the player is that the degree of challenge (types and numbers of enemies, for instance) will always be slightly higher than what the player is comfortable with, meaning that he or she will have to rise to the occasion in order to come out on top, either by trying out new tactics, by taking greater risks, or through sheer force of will and/or dumb luck.

As many of us can attest, trial and error difficulty treads a very fine line. Typically, too many failures, and players will become frustrated, while too many successes and players will feel as if the game isn’t going hard enough on them. The main issue with this, aside from basic balancing, is that different players have different thresholds for difficulty. Whereas a more casual player who’s just enjoying a game for its story will find that more than the occasional death is a turn-off, the hardcore player who plays on the “insane” setting will want to be challenged at every turn and made to work for every single victory. Ultimately a developer might run into a situation where they’re balancing not just one, but three or four versions of the same game, due to the different needs of different players.

Of course, pacing is also a chief concern by and large governed by the ebb and flow of difficulty, usually of the trial and error nature. The player needs to have portions of the game which fly by quickly and without too much issue, breaks in combat to absorb the world and feel unchallenged, and nail-biting experiences that are tense and have a feeling of urgency to these. Building these into a game when taking different gameplay preferences into consideration is a difficult process; after all, while it can be easy to balance a single encounter out to give the player the desired experience, doing so within the context of a full game is another thing entirely.

Adaptive difficulty settings are one way to get around this problem. On the most basic level, this will typically change the amount of resources (health, ammo, etc.) provided to the player, as well as the proportion of powerful versus weak items based on the player’s performance (i.e. more “full heal” pickups if the player is struggling). This feature is actually extremely common in games, either because developers want to avoid providing separate difficulty levels (a poor decision in my mind), or because players have a curious habit of selecting difficulty levels that aren’t appropriate for them (everyone has a different understanding of what “normal” should be).

Adaptive difficulty can be both explicit and hidden from plain sight. Prey, for example, has adaptive difficulty as a toggle option in the game’s options screen, and so it can be disabled based on the player’s preferences. Half-Life 2, on the other hand, while providing three difficulty settings (easy, normal and hard) also has a layer of code dedicated to analyzing the player’s progress in the game, level of resources, the ease at which certain encounters are completed, and so on; the game will then adjust the items enemies drop, the amount of resources available in breakable crates, and so on in order to make sure the player is always kept on edge by having “just enough” health and ammo to get through an encounter, but never quite enough to feel completely safe or fully-loaded. Other games will implement it in still subtler ways, like allowing the player to finish off a tough boss monster just a little bit more quickly than normal if the player’s death is imminent, creating a dynamic feeling of getting through by the skin of his or her teeth.

The biggest issue for me with adaptive difficulty is that, when left as a built-in feature that can’t be disabled, it removes control from the player’s hands.

Although I’ll usually take an entertaining and engaging experience over one that’s simply difficult for the sake of difficult, I also fully understand that some players don’t want hand-holding provided that they explicitly ask for it. Furthermore, adaptive difficulty can also lead to a feeling of predictability and sterility, without a hand-made feel to encounters (which was a major source of criticism for The Elder Scrolls IV: Oblivion). To this end, I feel that adaptive difficulty is best left as it is in Prey – a toggle switch in the options menu – or specific to a difficulty level, with the hardest mode taking off all assists, which mitigates the problem of too much challenge by allowing the player to rationalize it as his or her own choice (i.e. “well, I picked hardest, I should have known it would be too much for me”).

Endurance & Attrition

Another way to test the player focuses on the long term rather than the short term. All forms of endurance, at their most base level, revolve around resource management, with the player given a limited quantity of a valuable or vital item, its distribution carefully controlled. Resources are controlled in three main ways in just about every game:

1) “Random” drops. It’s quite common for enemies to part with valuables when defeated, or for the player to uncover supplies in crates, chests and so on. By tinkering with the tables that control those supplies, based on difficulty, the player’s progress, the amount of resources the player already has, and the player’s level of ability, character level, number of party members/companions, and so on, difficulty can be precisely controlled and monitored in order to provide a degree of challenge.

2) Attrition rate. Depending on the game, the rate at which a player burns through supplies can be highly variable. For instance, in a shooter, going up against a tough boss monster might not consume too much ammunition, but may consume a huge amount of health. Conversely, going up against many smaller hordes of enemies will end up with a player ill-equipped to proceed, but chances are, a healthy one. Learning to anticipate what the player needs in order to continue in the game is important. If a game uses an adaptive difficulty system, this might already be handled, but even so, careful consideration of how quickly the player goes through certain resources will lead to better encounter design and a game that feels more alive and responsive to the player’s needs. Strategically denying certain resources can be just as important as strategically providing them, too, in building tension and pacing the player’s progress.

3) Player ingenuity. Most common to role-playing games, smart players will often stock up on useful items like potions and ammunition before heading out into a difficult encounter; the duration the player can stay out in the wild before returning to stock up on supplies again is by and large controlled by the player’s prior action, as well as whatever the player might uncover during his or her outing. This is one thing that is hard to control in a game, and frankly, shouldn’t be. Keeping aware of what players can and can’t do, and building challenges around that is a good thing, as are systems, such as encumbrance and fatigue, which can provide a soft limit on how much the player can carry. However, imposing unreasonable hard limits (i.e. “you can only hold three health potions at once”) rarely feels like a fair way of managing this.

Long-term attrition may not be suitable for many games, but looking at attrition in different ways can actually reveal interesting opportunities for mechanics that may go unnoticed with a casual glance. For example, a puzzle game like Tetris has a strong element of attrition in the sense that the available space on the game board is continually shrinking based on the player’s performance, the difficulty level, and which puzzle pieces the player is provided with. On top of that, game speed is another gradually-depleting resource the player must carefully manage as things move quicker and quicker over the course of the game. There is a veritable economy of space and time in Tetris, even though there is no health bar, ammunition counter, etc. to speak of. Recognizing that attrition and endurance can exist as more than just basic physical resources will help flesh out and provide depth to existing mechanics.

“Fake” Difficulty

A subset of trial and error difficulty, what I’ll term “fake difficulty” here is something which is actually quite common in the games industry, but depends a good deal on the genre in question. Fake difficulty is a fairly broad spectrum of difficulty, but in common with all of the various permutations is the fact that they typically revolve around tricking the player or bending the rules of the game in order to provide their challenge – often causing significant frustration and annoyance for players, whether they’re keen to those tricks or not.

One of the most common forms of fake difficulty actually fits within the category of adaptive difficulty – namely, it revolves around manipulating the rules of a situation in order to provide the player with increased challenge, usually referred to as “rubber-banding”. The key difference is that while adaptive difficulty works in favour of the player (for example, you’ll find 50% more health kits if you’re low on health), fake difficulty tends to work in favour of the enemies or opponents.

However, since enemies rarely compete on fair terms with the player, and in fact tend to use an entirely different set of rules, this usually means that the bonuses given to the player’s opposition fall into the realm of super-human – increased speed beyond normal limits, temporary damage boosts, the ability to negate the player’s own abilities when normally they can’t, and so on.

A great (and persistent) example of this type of difficulty can be found in Mario Kart – in fact, the series is somewhat infamous for it. While the goal of the game’s rubber-banding is to provide a tense and exciting experience for the player, making sure that each race is as close a finish as possible, and that enemies are able to always keep players on their toes, in the long run, or for more experienced players, this form of difficulty tends to only breed contempt. While the illusion created is often enough to fool players who are of a lower skill level, as the effects are much more subtle and can often work in the player’s favour, when that same system is put up against players who are able to make a mockery of even the high difficulty levels, the computer is forced to go to incredible levels to try and keep up with the player, to the point of blatant cheating, gaining items and abilities far in excess of the player, and even defying the laws of physics (or whatever analogue exists in the Mushroom Kingdom).

Another form of fake difficulty that rears its head is that of the false challenge. In the false challenge, the player is typically asked to perform a standard feat – defeat some enemies, race to the finish in the allotted time, etc. However, what starts out as a relatively routine task quickly turns out to be an extreme test of reflexes and ability, as the player is beset with all manner of unpredictable obstacles, traps and powerful enemies. The key thing is that in all of these situations, the player is caught off guard, and unable to sufficiently prepare. Usually, this results in a quick and frustrating death, as the player likely felt he or she was successful up until that point. Worst, usually, the only way to surmount this type of challenge is to try it again, often from the very beginning of the sequence, armed with the foreknowledge of the hidden challenge ahead. When these are compounded one after the other, it can lead to rage-inducing moments for the player.

One game series which is notorious for this is Grand Theft Auto. While the game’s mission-based structure suggests that the challenges faced are relatively self-contained and straightforward, it’s very common for the games to prey on the player’s expectations in the worst way possible. One example from Grand Theft Auto: Vice City I frequently cite is a race sequence where the player has to reach a number of checkpoints in a set time. No big deal, right? That would be the case, if it wasn’t for the fact that other cars, trucks etc. are scripted to pull out around difficult corners and immediately as the player passes by at full speed – the player is almost guaranteed to hit these cars and ruin his or her attempt outright, unless he or she is able to slow down and let them pass instead. This just doesn’t happen once, but close to five or six times throughout the race, meaning that even if the player does everything right, there’s still a huge statistical probability that he or she will fail anyway, solely due to the designers pulling a fast one. A similar occurrence can be found in Max Payne, where enemies are scripted to throw grenades at the player at certain triggers, and these are literally impossible to avoid without prior knowledge.

Suffice is to say, fake difficulty, no matter the variety, isn’t fun for players, even if it’s built into the game with the best of intentions. Although often the goal is to provide an unpredictable or challenging experience regardless of the player’s skill level, more often than not it just comes across as mean-spirited, and at worst, can completely turn a player away from the game by rendering attempts at competition null and void. Unlike most forms of difficulty, this type is actually best avoided altogether, unless your goal is to make players hate your guts.

Random Number Gods

Although this is typically a type of difficulty reserved for strategy and role-playing games, random mechanics do exist in a wide variety of genres, whether they manifest in terms of how enemies behave in combat, the spread and accuracy of weapons, or whether or not the player is able to sneak by a foe successfully.

I’ve occasionally seen mechanics based on random elements derided by people, claiming that it takes away from the skill of the player to hinge success upon unpredictable odds. The key thing to understand about building difficulty out of a random number generator is that challenge is not substituted for “luck”, as some might claim. Rather, difficulty arises as the player is forced to respond intelligently to new developments that aren’t entirely predictable – it is the culmination of actions over a period of time that are important, not the individual actions themselves. Unlike trial and error, which typically tests reflexes and coordination, systems built on random elements test the player’s ability to respond to change and to cope with new situations.

As mentioned above, it’s also important to mention that random elements are often a staple in all types of games, regardless of whether or not difficulty is provided by trial and error, by manipulation of odds, or, ahem, fake difficulty. Driving a car in a racing simulation, for instance, there’s bound to be some random effect in the vehicle’s handling, or on varying types of terrain, even if it’s only a small piece of the overall picture. There is absolutely nothing wrong with this, because usually player skill is able to account for random elements anyway. More to the point, random doesn’t necessarily mean unpredictable – it just means that there can be a certain degree of noise or interference in playing the game, to prevent things from playing out exactly the same way every single time. Otherwise, when playing Tetris, we’d see the same blocks always become available in the same order, and that wouldn’t be nearly as fun to play, as the game itself is based wholly around bringing a degree of order to that randomness.

Unfortunately, building systems out of random number generators, particularly in role-playing games and strategy games, it’s easy to fall prey to a problem – not in the mechanics themselves, mind, but in the player’s perceptions and understandings of them. This usually manifests as what’s commonly called the gambler’s fallacy.

The simplest example is a coin flip. Even though a coin only ever has a 50/50 chance of landing heads or tails (assuming it’s a fair toss), we tend to assume that the 50/50 probability applies to all instances of the event in sequence, rather than the isolated event. In other words, we form a narrative as we flip that coin over and over again, perceiving each coin toss not as a single incident, but part of a larger whole – and as such, we also tend to assume that prior events have an influence on future events, or, put simply, that the more the coin lands heads, the greater the chances we think it has of landing tails.

In gaming terms, this can be described in the context of a turn-based role-playing game. A skill might have a 70% chance of success when used, yet we become frustrated when, turn after turn, the skill misses and we end up wasting both our time and resources trying to rectify the problem. What just happened? Surely, the game is fudging the numbers! Well, no, not really. We assume that, because the skill has a 70% chance of working, it should (or will) succeed seven out of ten times, like clockwork. This is, of course, not at all the case, as each individual attempt has the same odds as the last, and therefore, it’s possible to chalk up a huge string of losses despite what should be good odds.

There’s no easy solution for this problem, because you aren’t battling the numbers, you’re battling player expectations. Many developers actually get around this problem by instituting measures to make sure that random odds are, in fact, more predictable. For instance, if I have that 70% chance of success, I might program a clause into the game where it’s impossible to miss more than one time in a row – even if ultimately the math is completely off. That’s right, often, the random odds most players feel they rely on aren’t actually random at all, but instead manipulated to fulfill the expectations players have. The irony of all this is that usually the player only ever notices that there’s a “problem” if the math is correct in the first place. Obviously this is a controversial decision, and not everyone will agree with it one way or the other, but in the end it’s probably better to fulfill player expectations than it is for those same players to wind up frustrated over what they feel are unfair and incorrect odds.

Presentation is Everything

The header here might draw some ire, but I think that this is a lesson that is very much unsaid when designing games, and yet at the same time one of the most important to learn. Difficulty, as I’ve outlined, comes in many flavours and is highly subjective – however, it is also important to recognize that the way difficulty is presented to the player is also just as, if not more important. Similar to the gambler’s fallacy, sometimes it’s not a particular mechanic that’s the problem, it’s the way that players perceive it that’s at fault.

Let’s take a recent example in Dead Money, the Fallout: New Vegas DLC add-on. The game came under attack from both players and press alike for what they perceived as a steep difficulty curve. In Dead Money, the normal endless freedom of Fallout gives way to slavery, as the player is thrust into a very specific and mostly linear path through the game by way of a bomb collar, which will instantly kill the player if he or she strays too far for the beaten path. Many of the challenges in the game rely on destroying the radio transmitters that broadcast the detonation frequency, which are often hidden underneath tables, inside closets, or are otherwise difficult to reach. The goal in this situation is to create tension for the player as he or she desperately rushes to find the radio transmitter before his or her head is explosively removed.

It’s pretty clear, from an outsider’s perspective, to see why this mechanic would be frustrating to players. The bomb collar produces a high-pitched, persistent beeping when under threat of detonation, which players quickly learn to avoid like the plague, for one. There’s also something particularly demeaning about being enslaved in such a way by the antagonist. Other games that do this typically do so in such a way as so that the player regains his or her freedom quickly – while it’s a good way to breed contempt for the villain, draw it out too long and that contempt falls onto the game developer instead. Last, this kind of enforced limitation goes against what most players take the newer Fallout games for, namely, open-ended role-playing games with a variety of solutions for every situation; in Dead Money, frequently there is only one solution, and it’s often the one players aren’t happy with.

However, the problem with Dead Money isn’t the mechanic itself. Analyzed at a basic level, all it is a simple race against time to remove an environmental threat – turn off the switch before you die. The bomb collar mechanic, while effective in terms of the storyline, could have been replaced with any number of similar mechanics and still would have been just as effective. More importantly, it wouldn’t have been nearly as frustrating to players. For example, radiation and toxic hazards are extremely common in the Fallout world – why, then, didn’t Obsidian choose to instead implement the same threat in the form of radiation and, say, vents to clear it up? Interestingly, this variation actually exists in Dead Money, but is used to a much lesser degree. Had the bomb collar been replaced with a game mechanic which was functionally identical, but less at odds with Fallout’s design tenets, I think there would have been far fewer complaints about the game’s difficulty, because in that case, the challenge would have been perceived by players as fitting far better into Fallout’s world, and less limiting overall – after all, if it’s just radiation or acid blocking your way, that’s a much more incidental threat than the villain’s scheming, which if anything comes across as deliberate griefing.

Looking around, I think you’ll find more and more examples of perception of difficulty being a bigger problem than the difficulty itself. I can already think of a few off the top of my head – the jarring and repetitive taunts made by the bosses in Deus Ex: Human Revolution, for instance, are extremely grating on the nerves even if the boss fights themselves aren’t overly challenging with a little preparation. Usually, in fact, associating a character with a given type of difficulty (say, Boswer and his castles in Super Mario Bros.) can quickly cause players to become frustrated and annoyed in situations when that character is either already rather annoying, or when the game mechanics themselves aren’t enjoyable – it gives people a face to yell at.

Conclusion

This analysis, while far from complete, should have given a pretty good overview not only of a few different types of difficulty, but it should also have made understanding why people get upset at different types of games, different scenarios, and different sorts of difficulty a bit clearer. Creating and fine-tuning difficulty is always an ongoing process, and it’s extremely difficult to get it right for all players. Even so, hopefully this piece has shed some light on exactly why that is, and what steps can be taken at a more fundamental design level, in order to ensure that your game is fun to play, and challenging, without being frustrating as well. (Source: Gamasutra)