作者：Lennart Nacke

欢迎来到本课程的第四节课：关于游戏设计的基本介绍。务必确保在继续阅读前先了解教学大纲和课程信息。今天我们将讨论游戏中的系统动态。本文将严格遵循我们的教科书（《Game Design Workshop》第5章，《Challenges for Game Designers》第2章以及《Salen and Zimmerman Rules of Play》的第13，14，16，17和18章）。我们之前曾讨论过规则的使用。作为游戏设计师，我们会使用规则去决定玩家所采取的行动以及这些行动的结果。在数字游戏中，游戏逻辑经常能够提供游戏的部分规则。你的游戏的视听表现（甚至是游戏的故事）并不是游戏形式元素的组件。当视听元素影响着你的游戏的形式结构时，它将被当成游戏规则的元素。Salen和Zimmerman便区分了基本规则和操作规则以及隐含规则。

基本规则是关于游戏的内部事件。它们是游戏背后的主要逻辑。在数字游戏中，这些规则是直接包含于游戏代码中。

操作规则是允许游戏所需要的所有规则（不只是组成事件或内部事件），包含了所有与你的游戏相关的外部事件，如游戏输入和输出，你在游戏中传达选择的方式以及如何向玩家传达结果等等。

隐含规则是游戏的未声明假设（通常与玩家的荣誉守则相似，但同时也与你的游戏所运行的计算机平台的属性相关）。隐含规则经常与我们认为理所应当的游戏的环境相关。然而这一环境是用于试验游戏设计的创造性。

作为系统的游戏

就像我们之前所谈到的，理解游戏的一种有效方式便是将其分解为不同系统。系统本身是由一套相互影响并因此形成一个整体的元素进行定义。我们已经意识到这一定义与我们对于游戏是带有界限（将其与外部世界隔离开来）的魔法阵的理解非常相近。为了创造更棒的系统，我们需要理解基本的系统元素，如互动质量，系统发展以及系统随着时间的改变。当系统开始运行时，系统中的元素将相互影响以实现共同目标。系统中的元素将引导着其互动质量。同样地，在游戏中，形式（和戏剧化）的元素将在运行时创造一种复杂且动态的玩家体验。在着眼于系统在运行时如何做出回应前，我们首先需要理解它们的基本元素。这些元素的一些组成部分将决定系统在运行时的表现。然而当系统与其它功能区分开来时，它们的功能将对其状态产生影响：

由以下内容定义的对象或元素：

结构或属性

行为

关系

对象

对象是系统的基本构件。系统拥有一些相互联系的组块，并且这些组块是系统的对象或元素。它们可以是实体的。例如：游戏组块，网格面板上的方块，体育场上的线，玩家自身。也可以是抽象的。如游戏中的概念。也可以是这两者的结合。例如：玩家的表现可以是抽象的也可以是实体的。

在《卡坦岛》中，你便拥有许多不同的游戏对象。《卡坦岛》中的对象包括玩家和强盗，道路和殖民地/村庄组块，开发或资源卡片，特殊点数（最大的军队，最长的道路），带有资源的地形砖块，地形数和筛子。桌面游戏中的所有这些对象组成了游戏系统。它们都带有属性，行为和关系。如果遗漏了任何对象，游戏便不能完成设计。例如，如果不存在殖民地组块或道路，玩家便不清楚自己在创建某些内容。如果遗漏了资源砖块，游戏也就失去了意义，因为玩家将不清楚如何收集新资源，或者哪个玩家将收集一种特定的资源。如果没有筛子，游戏也就失去了机会元素，并且会因此发生巨大的改变（尽管筛子元素可以被基于技能的玩家挑战所取代）。

属性

以下例子向我们呈现了《卡坦岛》中的一些对象（如道路，骑士，殖民地和城市扩展等等）是如何拥有一些附加成本。这是关于游戏属性价值如何发挥作用的一个简单的例子。例如一条街道需要花费1个木头和1个砖块。那么这不仅是道路对象的价值成本，它们同时也建立起了道路和资源之间的关系，即木头和砖块。

对象形式是由实体或概念属性所定义。属性是定义游戏对象性质的价值集合。例如在角色扮演游戏中，角色（和道具）能够拥有价值，如优势，生命力或经验值。游戏对象的视听媒体代表同样也被当成一种属性值（如与游戏对象相关的图像精灵）。游戏元素的属性形成了一个数据块，并且能够描述游戏系统中与游戏对象可能出现的互动。游戏系统中的对象越复杂，那么与这种游戏对象之间的互动也就变得更加难以预测。

在上述的例子中，我们可以看到游戏对象是由其属性所定义（就像《边境之地》中的武器）。想象如果你需要在数据库中设置“枪支”对象，你便需要明确所有的这些属性，如名字，武器类型，牌子，破坏力，精确度，射速，增强功能，弹夹大小，货币价值，图像或可视模型。当你在设计一款游戏时，你可以根据对象的重要性去考虑它的所有细节。之后你将花些时间去调整并平衡这些价值。许多游戏设计师更习惯将这些数值保存在电子表格中（或者数据库软件中），从而基于游戏内部互动去估算数值的变化。特别是游戏内部的战斗主要是依赖于属性将创造游戏系统中的不同关系（例如属性将决定战斗中的单位的性能）。破坏力估算经常包含于游戏对象属性和与机会相关的规则。

行为

我们可以在游戏中面向非玩家角色（NPC）而执行的人工智能（AI）脚本中看到这些行为。此外我们也可以在《卡坦岛》的卡片（例如指导玩家“当你创建这个殖民地时，你便能够将命运卡片翻过来”的殖民地卡片）中看到行为。行为指代的是游戏对象能够在特定游戏状态中执行的潜在行动。

游戏对象的行动更多，游戏对象的行为便更难预测。游戏的基本规则能够告诉我们游戏中的可能行为是什么，但操作规则却仍然能够影响行为，并引起意外的游戏玩法动态。关于行为复杂性我们需要记住的一点是，更多游戏玩法复杂性并不总是等于更多游戏乐趣。

关系

明确彼此间的关系是系统中元素的一种本质特征。如果我们拥有一套带有属性和行为的随机性对象集，但是它们彼此间却没有关系，那么我们所拥有的便不是一个系统，而只是一个集合罢了。在游戏中，我们很容易表现出关系。例如，在游戏面板中定义对象的位置或在纸牌游戏中明确纸牌数量。关系可以由固定关系，线性关系，松散的对象关系或在游戏玩法过程中可能发生改变的关系组成。卡片集的数量层级将决定桥牌中的卡片间的逻辑关系。系统元素间的关系定义是由系统运行时所呈现的动态体验所决定。有些对象可能与对象接近它们或游戏元素基于某种特定状态时所触发的系统中的其它对象具有松散的关系。关系间最有趣的一面便是它们能够基于玩家选择或在基于机会的事件中发生改变。

机制，动态，美学

在2011年GDC大会上的演讲中，Clint Hocking提出了一个问题，即游戏如何为玩家创造意义，并通过动态去解释游戏创造的意义而回答了这一问题。他将这一理念与Hunicke，LeBlanc和Zubek名为《MDA: A Formal Approach to Game Design and Game Research》的研讨论文联系在一起。该论文是最先尝试形式化游戏设计的内容之一，并得到了许多游戏设计师的采纳。它认为游戏系统包含了：

机制。这指的是核心层面的特定游戏组件（例如数据表达或算法或规则层面）。

动态。这是指在玩家与游戏互动的时候开启机制和机制的运行时间行为。这同样也是随着时间的发展玩家和游戏系统的输入和输出内容的价值改变循环。

美学。这指的是玩家的体验，在感知到游戏外观和感觉并与之互动时的理想情感回应。

Clint Hocking将MDA改成RBF从而让这一理论结构的意思变得更加清楚：

规则。机制是等价于游戏规则。

行为。动态是游戏玩家系统的运行时间行为。

感觉。美学是游戏唤醒玩家的感觉。

该演讲之后讨论了一个关于将MDA付诸实践的例子，就像Stephen Lavelle在游戏《洞穴探险》中所讨论的那样。

我们可以通过着眼于《洞穴探险》中的鞭子武器去审视MDA的行动。武器机制是指它拥有一个附加动画，能够在使用前提升鞭子的准确度，这同样也意味着鞭子的命中区在玩家身后和上方。这便是鞭子机制。

鞭子的动态在于它是一种缓慢的武器，玩家如果使用它便很难攻击到飞翔的敌人。然而，如果谨慎使用的话，鞭子便能够准确打到玩家上方的敌人。

最终氛围和体验是，《洞穴探险》让人觉得比枪战游戏聪明点。这指的是玩家在玩游戏时的感觉。Hocking在演讲中提的问题是，来自规则的意义将控制鞭子或者玩家如何使用鞭子。理解动态的运行的麻烦是源自我们尝试着将玩的意义当成一个动词。在游戏环境以外，玩可以作为一个动词，例如玩音乐。从数据看来玩是否只是一种执行行为（例如乐谱上的注释或游戏中的规则），或者它是否能够提供更深入的意义，如你个人如何执行这一行动？关于玩家执行行动的数据的感觉和鉴别是指该行动最终为他们创造了怎样的体验。Hocking认为游戏设计师可以强调作者驱动的游戏，即大多数意义都是源自机制，玩家不能获得过多的解释（例如《特殊行动：一线生机》），或玩家驱动的游戏，即设计师将把决定权让给玩家。

系统的复杂性

“复杂性并不只是拥有多个部分的系统问题，这是基于某种并不简单的方式的相互关系。”—-Jeremy Campbell

游戏系统是可能性空间（例如“井字游戏”的可能性空间可以被创造成树形结构）。你所作出的选择将决定系统的动态。在系统的动态中，系统的复杂性将变成一个重要元素。Christopher Langton是基于如下4个层面理解系统的复杂性：

固定的系统并不会发生改变。系统中的元素关系是相同的（就像黑白电视的屏幕）。

定期的系统会不断重复同样的模式。如果你拥有一个信息系统，那么信使将在两个派系间来回奔跑，但前提是你拥有一个定期的系统。

混乱的系统在元素关系中并不是随机且动态的，它们反而比定期的系统更加复杂且难以预测。

“意外是超出于依赖环境的互动产品之外。”—-John Holland

复杂系统非常稀有，并且经常依赖于许多条件去创造复杂性。简单的规则集经常可以成就复杂的游戏玩法体验。当系统基于简单的规则生成复杂且难以预测的行为模式时，我们将其称为意外。

关于意外的一个典型例子便是Conway的生命游戏（游戏邦注：英国数学家John Horton Conway在1970年发霉的细胞自动机），它遵循了细胞网格中的一个非常简单的规则集：

1.细胞的诞生。如果三个相邻的细胞活着，那么细胞便会存活于下一代中（既算式的下一循环或阶段）。

2.因为孤独而导致的细胞死亡。如果细胞周围有少于2个活着的细胞，它便会在下一代死亡。

3.人口过剩而导致的细胞死亡。如果细胞周围有超过4个活着的细胞，它便会在下一代死亡。

意外系统将为游戏设计师提供一个有趣的复杂性作为简单的规则，并通常能够创造出华丽且复杂的游戏场景。另一方面，这些系统总是很难达到平衡。

经济系统的例子

我们通过创造稀缺的游戏对象或使它们成为对玩家非常有用的内容去创造它们在游戏中的价值。有些游戏也允许我们在玩家间交换资源。在游戏中允许玩家进行简单的交易便形成了大多数游戏的基本经济。通常情况下交易都是有限的，并且游戏经济是受控制的，并不像任何现实生活中的经济那样。为了创造一个基本的经济，你应该允许玩家进行交换：

道具。这些都是可被交换的对象。通常情况下它们是指游戏资源以及游戏中其它可收集的事物。

资源。它们是引导着交易的实体。通常情况下它们是指玩家或某种形式的银行，或者游戏中的拍卖行。

方法。这些都是交易的机遇。它们可以是游戏中的市场。

为了促进交易，经济可以使用货币。对象的价格是取决于游戏设计师所设定的市场控制。同样地，游戏中的交易机遇也可以进行调节，或允许完全的自由交易。

物物交换

游戏中的物物交换系统既可以简单也可以复杂。简单的物物交换例子有游戏Pit，在这里你的目标便是垄断市场。游戏中的卡片数是固定的。这为经济系统提供了数量稳定的产品。卡片的价值同样也不会发生改变。游戏中的所有交易都必须是基于同等数量的卡片，这意味着经济系统中的价值具有固定的价格。游戏中的这些市场规则意味着游戏中经济是不可能得到发展的。还有一个更复杂的物物交换系统例子，即《卡坦岛》。在这里，资源的价值是取决于生产出的资源数量（这与筛子的随机性以及游戏一开始的资源数相联系）。这同时也会改变经济中的资源总量。尽管4:1的交易系统（伴随着游戏银行）是作为通货膨胀控制，但根据常态分布，手上握有较多资源卡片的玩家最有可能遭到惩罚。任何带有超过7张卡片的玩家必须将手上一半的卡片还给银行。

市场

市场系统将为了交易使用货币。这使得他们会比物物交换系统更加复杂。让我们列举一个简单的市场例子，即桌面游戏《大富翁》，在这款游戏中，不动产的数量是有限的，但是不动产的价格是随着玩家的目标而波动。一开始玩家都是拥有固定数量的钱，但他们每个回合在通过Go后将会有稳定的收入。银行所提供的钱没有上限。市场的有趣元素在于它能决定不动产的价值。首先，玩家能够购买房地产，但如果他们拒绝在那时候购买，那么该房地产将被放到拍卖行让其他玩家进行拍卖。这里的市场价值是由玩家的目标以及已经被购买的房地产的竞争性所决定（因为拥有同样颜色的房地产具有很大的好处）。

我们可以在MMORPG的拍卖行和虚拟经济中看到一些更复杂的市场例子。玩家一开始只拥有少量的资源，并需要基于这些经济花费时间去收集虚拟资源。玩家与游戏系统之间可以进行交易。在这一经济中，供需将影响市场的价值。

系统反馈

反馈循环是游戏系统中的重要组成部分。它们可以帮助你平衡游戏系统并提升它的竞争性。例如，如果你拥有一个游戏系统，那么不管何时玩家获得一个点数，他们便能够获得像一个额外的回合等奖励，然后你便能够增强奖励的正面影响并为玩家创造一个优势。好人总是能够更快地变得更好。这便是所谓的积极反馈循环，它能够推动游戏玩法，因为玩家能够更快地朝着目标前进，并因此导致其他玩家更难追上他们。根据你的游戏是否依赖于分数评价，这一循环将快速将玩家引向游戏终点。积极反馈循环能够增强玩家系统的关系。

另一方面，消极反馈循环能够增强玩家之间的凝聚力。让我们想象在一款游戏中，每次当你获得一个点数，你都需要将自己的机会让给其他玩家。这一系统告诉玩家不要获得与你一样多的点数，并削减了你获得点数的优势。在这里，消极并不等于坏事，但它却与减去某些内容的理念相似。你的可变增益将变成损失。在《马里奥赛车》中，当你不能如期完成一场比赛时你将能够使用一些更厉害的道具，如果你能够有效使用它们，它们将帮助你平衡游戏并追赶上其他玩家。在桌面游戏或回合制数字游戏中，这也能够用于平衡第一个移动优势。此外，消极反馈循环还能够平衡玩家系统间的关系。

（本文为游戏邦/gamerboom.com编译，拒绝任何不保留版权的转功，如需转载请联系：游戏邦）

Introduction to Game System Dynamics

Lennart Nacke

Welcome to the fourth week of class in the course: Basic Introduction to Game Design. Make sure to read the syllabus and course information before you continue. Today, we are going to discuss system dynamics in games. This text follows closely from our textbooks (Game Design Workshop, Chapter 5, Challenges for Game Designers, Chapter 2, and Salen and Zimmerman Rules of Play chapters 13,14,16,17,18). In previous lectures, we have discussed the utility of rules. As game designers, we use rules to determine the actions players can take and the outcome of those actions. In digital games, the game logic often provides parts of the rules of your game. The audiovisual manifestation of your game (even the story of your game) is however not considered a component of the formal elements of games. When audiovisual elements influence the formal structure of your game, this should be considered as a factor of your game rules. Salen and Zimmerman distinguish between constituative rules and operational rules as well as implicit rules.

Constituative rules are all about a game’s internal events. They are the main logic behind your game. In a digital game, these are contained directly in the code of your game.

Operational rules are all the rules needed to run the game (not just the constituative or internal events) including all external events related to your game, such as input and output of the game, the way that you express choice in your game and how outcomes are defined for players.

Implicit rules are the unstated assumptions of a game (often similar to a player’s honour code, but also relating to the nature of the computing platform that your game runs on). Implicit rules often relate to the contextual situation of a game that we are taking for granted. However, this contextual situation can be played with, to experiment with innovations in game design.

Games as Systems

As we have discussed in class before, a good way to understand games is to break them down into systems. Systems themselves are defined as a set of elements that interact with one another to form an integrated whole. A system has a boundary and surrounding elements. We already see that this definition comes close to our understanding of games as a magic circle with a boundary that delineates it from the outside world. To create better systems, we need to understand basic system principles, such as interaction quality, system growth and the change of the system over time. When a system is set in motion, the elements of the system will interact to produce a common goal. The elements of a system guide its interaction quality. Similarly, in games, the formal (and dramatic) elements that we have discussed before will create a complex and dynamic player experience when set in motion. Before looking at how systems react when set in motion, it is important to understand their basic elements. Several factors of these elements determine how the system will behave when set in motion.
However, there is even more to systems as they are distinguished by their features that all influence the state of a system:

Objects or elements, which are defined by all of the below items

Structure or properties

Behaviour

Relationships

Objects

Objects are the basic building blocks of a system. Systems have pieces that relate to one another and these pieces are the objects or elements of the system. They can be:
Physical. For example: game pieces, the squares on a grid board, the lines on a sports field, the players themselves.
Abstract. For example: In-game concepts.

Both. For example: Player representations that can be both abstract and physical.

In Settlers of Catan, you have many different game objects. The objects in Settlers of Catan are the player and robber pawns, roads and settlements/village pieces, cards for development or resources, special points (largest army, longest road), terrain tiles with resources, terrain numbers and dice. All these objects in the board game make up the game system. They all have properties, behaviours and relationships. If any of the objects were missing, the game would not proceed as designed. For example, if there were no settlement pieces or roads, the players could not indicate that they have built something. If the resource tiles were missing, play would be meaningless, because it would not be clear how new resources would be gathered or which player would earn a specific resource. Without a dice, the chance element of the game would be missing and the game would change completely (although the dice element could be replaced with a skill-based player challenge).

Properties

The below example shows us how some Settlers of Catan objects (e.g., a road, a knight, a settlement and the city expansion) has some costs attached to it. This is a very easy-to-understand example of how game property values work. For example, a road costs 1 wood and 1 brick. Not only are these the cost values of the road object, but they already establish the relationship (another system feature) between roads and resources, such as wood and brick.

Object forms are defined by attributes that are either physical or conceptual in nature (see above). Properties are the sets of values that define the nature of game objects. For example, in role-playing games, characters (and items) can have values, such as strength, vitality or experience level. The audiovisual media representation of a game object is also considered a property value (e.g., the sprites or the artwork associated with the game object). The properties of a game element form a data block that is able to describe the interactions that are possible with a game object in the game system. The more complex an object is in a game system, the less predictable the interactions with this game object become.

In the above example, we can see how a game object – in this case a weapon in Borderlands – is defined by its attributes or properties. Imagine if you had to put this “gun” object into a database, you would need to specify all these properties. For example: a name, what type of weapon it is, what make, damage, accuracy, fire rate, enhancements, clip size, money value, an image or visual model representing it. You can see how important it is to think about all the details of your game objects when you are designing a game. You will later spend a lot of time tweaking and balancing these values. Many game designers prefer to have these values saved in a spreadsheet (or – sometimes – database software) to be able to calculate the changes of values on in-game interactions. Especially, in-game combat relies heavily on how properties create different relationships in your game systems (e.g., properties determine how effective units are in combat). Damage calculations often involve rules relating to game object properties as well as chance.

Behaviours

We can see behaviours most commonly in artificial intelligence (AI) scripts executed for non-player characters (NPCs) in games. However, behaviours can also be seen on cards in the above example of Settlers of Catan (e.g., the settlement card instructs players: “When you build this settlement, you may flip over the destiny card.”). Behaviours refer to the potential actions that game objects could perform during a given game state.

The more actions are possible for a game object, the less predictable the behaviour of the game object. The constituative rules of our games inform what behaviours are possible in a game, but the operational rules can still influence behaviours, often leading to emergent gameplay dynamics. One thing to keep in mind regarding behaviour complexity is that more gameplay complexity does not always equal more fun of playing.

Relationships

Having relationships among one another is one of the defining characteristics of elements in a system. If we have a random set of objects with properties and behaviours that do not relate to one another, we have a collection, but not a system. In games, relationships are easy to express. For example, by defining the location of objects on a game board or numbering the cards in a card game. Relationships can consist of fixed, linear relations, loose object relationships, or relationships, which can change during gameplay. The number hierarchy of a card set determines a logical relationship between the cards in a deck. The definition of the relationships of system elements is largely responsible for the dynamic experience that occurs when a system is set in motion. Some objects might only have loose relationships with other objects in a system that are triggered when an object is close to them or when a game element is set to a specific state. One of the most interesting aspects of relationships is that they can change based on player choice (as determined by the operational rules of the game) or through chance-based events.

Mechanics, Dynamics, Aesthetics

In a GDC 2011 talk, Clint Hocking asked the question of how games create meaning for players and answered the question by explaining that games create meaning through their dynamics. He relates this idea back to a workshop paper from Hunicke, LeBlanc and Zubek titled MDA: A Formal Approach to Game Design and Game Research (PDF). The paper was one of the first attempts to formalize game design and has since been adopted by many game designers. It defines a game system as consisting of:

Mechanics. This refers to specific game components at the core level (i.e., the level of data representation or algorithms or rules).

Dynamics. This is the putting in motion of the mechanics, the run-time behaviour of the mechanics when the player interacts with the game. It is also value-changing loop of inputs and outputs of player and game system over time.

Aesthetics. This refers to the experience of the player, their desired emotional response when they perceive the look and feel of the game system and interact with it.

Clint Hocking re-appropriates MDA as RBF to make his (and many other game designers’) interpreted meaning of this theoretical structure a bit clearer:

Rules. Mechanics are equivalent to the rules of a game.

Behaviours. Dynamics are run-time behaviours of the game-player system.

Feelings. Aesthetics are the feelings that the game evokes in the player.

The talk then discusses an example of MDA put into action as discussed by Stephen Lavelle in the game Spelunky.

We can examine MDA put into action by looking at the whip weapon in Spelunky. The mechanic of the weapon is that it has an animation attached to it that raises the whip before its use, it also means that the hit box of the whip goes behind and above the player character. This is the whip mechanic.

The dynamic of the whip is that it is a slower weapon that makes it harder to attack flying enemies. However, if deliberately used, the whip can be deadly as it hits enemies above you.

The resulting atmosphere and experience of deliberation is that Spelunky feels a bit smarter than shoot ‘em up games. This refers to the feelings that the player has when playing the game. The question that Hocking asks in his talk is whether the meaning (and the feeling of of premeditative deliberation in Spelunky) comes from the rules governing the whip or from how the player uses the whip. The trouble of understanding how dynamics work comes from trying to understand what exactly play means as a verb. Play can be used outside of a gaming context as a verb, too, for example when playing music. Is play just the act of performing on data (e.g., the notes on a sheet of music or the rules in a game) or does it give deeper meaning exactly by how you perform this as an individual? The feeling and appreciation of the data that a player performs on is what ends up creating the experience for themselves (and potentially others). Hocking thinks that game designers can emphasize either author-driven games, where most of the meaning comes from the mechanics and not much interpretation is allowed for the player (Spec Ops: The Line comes to mind again) or player-driven games where designers abdicate authorship as much as possible to their players. In the video below, you can see an interesting example of how an extremely rare reward (remember that value is tied to scarcity) in a game like World of Warcraft can influence player experience (make sure to listen to the sound in the video).

Complexity of Systems

“Complexity is not just a matter of a system having lots of parts, which are related to one another in nonsimple ways.” (Jeremy Campbell)

Game systems are possibility spaces (e.g., the possibility space of Tic Tac Toe can be modeled as a tree structure). The options that you chose determine the dynamics of the system when it falls into place. Complexity of a system becomes an important factor in the dynamics of a system. Christopher Langton (as mentioned in Chapter 14 of our Rules of Play textbook) understands the complexity of systems at four levels:

Fixed systems do not change. The relationships of the elements in the system remain the same (like a black TV screen).

Periodic systems repeat the same patterns over and over again. If you had a messaging system, where a single messenger just runs back and forth between two factions, you have a periodic system.

Chaotic systems have elements that are constantly changing, but are random in their object states and relationships.

Complex systems, finally, are not random and dynamic in their element relationships, but they are more complex and less predictable than periodic systems.

“Emergence is above all a product of coupled, context-dependent interactions.” (John Holland)

Complex systems are quite rare and often depend on a lot of conditions working in tandem to create the complexity. Simple rule sets can often lead to complex gameplay experiences. When systems generate complex and unpredictable behaviour patterns based on simple rules, we call this emergence.

A good example of emergence is Conway’s game of life, which follows a very simple rule set on a cell grid:

1.Cell birth. A cell becomes alive in the next generation (next round or phase or step in the algorithm) if three of the neighbouring cells are alive.

2.Cell death by loneliness. A cell is dead in the next generation if it has less than two alive surrounding cells.

3.Cell death by overpopulation. A cell is dead in the next generation if it is currently surrounded by more than four alive cells.

The glider is a walking variant of the game of life rules.

Emergent systems provide an interesting complexity for game designers as simple rules can often lead to beautiful and complex gameplay scenarios. On the other hand, these systems can be very hard to balance.

Economic System Examples

We create value in games by making game objects either scarce or making them really useful for players (principles of scarcity andutility). Some games also allow us to exchange resources among ourselves (between players) and with the game system. Allowing simple trades in games forms the basic economy of most games. Often the trades are limited and the economy in a game is controlled and does not resemble any real-life economy. To create a basic economy, you should allow the exchange through:

Items. These are the objects being traded. Often they are game resources and other collectible things in games for which you can barter.

Resources. These are the entities conducting the trades. Often they are players or some form of a bank or a game auction house.

Methods. These are the opportunities for trading. These can be in-game markets, for example.

To facilitate trading, economies can use currencies. The prices of objects depend on the market controls that game designers put into place (e.g., things can be free, fixed price or controlled by the market). Similarly, trade opportunities in games can be regulated or allow complete freedom of trade.

Bartering

Bartering systems in games can be simple or complex. A simple example of bartering is the game Pit, where the goal is to corner the market. The number of cards in the game is fixed. This provides a stable amount of product for the economic system. The values on the cards also do not change. All trades happening in the game must be for equal numbers of cards, which essentially means that the value objects in the economic system have a fixed price. These market regulations in the game mean that economic growth in the game is not possible. A more complex bartering system example is Settlers of Catan (again). Here, the values of resources fluctuate depending on how much of a resource is produced (which is tied to the randomness of the dice and the assignment of numbers to resource tiles at the beginning of the game). This also changes the total amount of resources (i.e., the product) available in the economy. While the 4:1 trading system (with the game bank) serves as inflation control, the high likelihood of a seven (according to a normal distribution) being rolled with the dice punishes players holding too many resource cards on hand. Any player with more than seven cards will have to return half their hand to the bank.

Markets

Market systems employ currencies for their trades. This makes them more complex than bartering systems. A simple market example is the board game Monopoly, where the number of real estate available in the game is finite, but the prices for the real estate fluctuate significantly based on player goals. Players start with a fixed amount of money, but have a steady income by passing Go (the starting square) every round. There is also no cap on available money from the bank. The interesting aspect of the market is how the value of real estate properties are determined. First, a player may purchase the property at the title deed, but if they decline to purchase at that point, the property goes up for an auction among the remaining players. The market value here is determined by player goals and by the competition arising from already purchased properties (since there are significant benefits to having properties of the same colour).

More complex market examples can be found in MMORPG auction houses and virtual economies. Players start out with little resources and will have to put time into gathering virtual resources (a process that also relates to gathering experience and is called grinding) within those economies. Trading is possible between players and with the game system (in shops). Supply and demand influence the market values in this economy. See also the above video about virtual inflation.

System Feedback

Feedback loops are important parts of the game system. They can help you to balance your game system or make it more competitive. For example, if you have a game system, where whenever a player scores a point, they get a reward like an extra turn, then you are reinforcing the positive effects of your reward and create an advantage for that player. This promotes divergence in the game. Good people will become better much faster. This is called a positive feedback loop and it can be used to accelerate gameplay, because players are able to move faster toward their goal and it makes it harder for other players not doing so well to catch up. Depending on whether your game depends on a scoring evaluation, this loop can lead to the endgame quickly. Player-system relationships are reinforced by a positive feedback loop.

On the other hand, negative feedback loops exist to promote cohesion among players. Imagine an example, where every time you score a point in a game you have to pass your turn to another player. This system would favour people not scoring as many points as you and subtract from your advantage gained by scoring a point. Negative is not equivalent with bad here, but it relates to the idea of subtracting something. Your variable gain is turned into a loss. The blue shell (see video below) in Mario Kart games is a very well-known item that facilitates a negative feedback loop. In general, in Mario Kart, many higher power items only become available to you when you are behind in the race and if you use them well, they can help you balance out the game and catch up to the other players. In board games or turn-based digital games it can also be used to balance out the first move advantage (see other video below). Player-system relationships are balanced out by a negative feedback loop.(source:gamecareerguide)