Game Mechanics

Game Mechanics

When we play games, typically we are engaging with a system that allows us to interact with the game. Even the simplest of games like "rock, paper, scissors" has a structure and pattern to it in the form of a game mechanic, and the incredibly complex games found on the market today undoubtedly contain similar complex systems comprising of multitudes of functions and mechanisms for the player to use. However, an issue arises as to what exactly constitutes a game mechanic. Lacking from the game industry is what could be described as a solid, "unified definition of game mechanics that gives... a practical base upon which to build" (Cook, 2006, p. 1) and design games. Currently, there are various definitions that offer similar, but varying explanations as to what a game mechanic is; in order to best determine how SRK Framework can be applied to game design; some clarification of what defines a game mechanic is needed.

Lundgren and Björk (2003) offer the definition that a game mechanic is a simple construct that specifically covers a single type of interaction within the larger rule system present within a game, or is a much larger collection of game mechanics that follow similar constructs under the watch of a primary mechanic. In this sense, the rule system of a game may have multiple game mechanics, covering either a general or specific aspect of the game. An example of this would be a trading mechanic in a strategy game; the aspect of that mechanic would be that players can possibly trade with each other during a game. More specific mechanics would cover the specifics of what, when, and how players can trade, (Lundgren and Björk, 2003). Sid Meier's Civilization IV follows along this game mechanic definition; players are able to trade resources with each other or AI-controlled players, the act of trade representing the general mechanic/collection, and then various mechanics control what can be traded at what time. Specific mechanics within the general mechanic of trade in the game control exchanging of resources, technology, cities, and units amongst players; this can be done provided certain requirements are met. A player wishing to trade maps of the game world with other players need to have a specific technology to do so, and in order to trade in-game resources, players must have trade routes established with each other (Firaxis Games, 2005). A game mechanic is more or less a rule of the game and based on how a player interacts with the game rules.

Similar definitions, such as game designer Daniel Cook's definition of game mechanics being "rule based systems / simulations that facilitate and encourage a user to explore and learn the properties of their possibility space through the use of feedback mechanisms" (Cook, 2006, p. 1) continue on with the discussion of game mechanics being a rule or set of rules in regards to the game environment, but also considers the player's relationship with the mechanics as well. First, a player performs an action in the game environment. This in turn causes an effect within that environment, providing the player with feedback as to the results of the initial action. Using that feedback, the player can then perform another action to cause another effect and in turn gain more feedback, and so on and so forth. The key aspect of Cook's offered definition of a game mechanic is that exploration of the game environment through action and feedback is a primary requirement in order for a game to be considered a game. Cook provides an example:

I can put a black box on the table with a hidden button. Unbeknownst to a potential user, pressing the button enough times and the black box will spew out a thousand shiny silver coins. This is not a game. This is a bizarre gizmo. (Cook, 2006, p. 3)

Under Cook's definition, three criteria need to be fulfilled in order for a game mechanic to be considered a game mechanic. First, a mechanic needs to instruct the player as to what actions to take, enable the player to ability to clearly see the impact they have on the game environment, and provide information as to the possible end result of their interactions. A "system that encourages learning through strong feedback mechanisms" (Cook, 2006 p. 4) and meets those three requirements can be considered a game with developed game mechanics.

Sicart (2008) in his article "Defining Game Mechanics" offered a formal definition of game mechanics, based off an examination of previous and current research into both game mechanics and game design: "Game mechanics are methods invoked by agents, designed for interaction with the game state" (Sicart, 2008, p. 5). In breaking down this definition, methods are the behaviors, actions and functions available within the constraints of a game environment to the 'agents' , which are any involved parties in the game; a human player, an AI or a part of the computer system can be considered agents that can interact with mechanisms present within the game. Sicart states that in including AI/Computer systems under the umbrella of being 'agents', it helps provide information to the stability of the game system as a whole; if the actions of an AI controlled character aren't bound to the constraints of the game world just as a player's actions and behaviors are, it may cause instability in the game's other mechanics. The same can be said in the case of the AI having access to actions or behaviors unavailable to the player (Sicart, 2008) and considerations aren't taken to ensure that the AI-only actions do not disrupt the overall game system.

For the purposes of this thesis, Sicart's (2008) definition of game mechanics will be used in comparison to Rasmussen's SRK Framework, with some modifications made in regards to focusing on human players as the agents in the definition, and taking into account their cognitive behavior. The measurement of AI players and computer systems is unfortunately beyond the scope of this thesis. Lundgren and Björk's (2003) division of how there are general and specific types of mechanisms present in a game environment will also be used in conjunction with terms of dividing types of game mechanisms into three separate categories: core, primary and secondary game mechanics.


In game design literature, game mechanics are often categorized without a clear description of which concept of game mechanics is being used (Sicart, 2008). Most game mechanics can be described as "usually just a function...given a certain input" (Sigman, 2009) to create a certain result, but given how common versus how rare a game mechanic can be in a game environment, and how multiple game mechanics can be used to achieve the same end state, or the actions/behaviors available in a mechanism, it is necessary to draw lines between certain types of mechanics so as to differentiate between their place and influence over a game environment. Following along with Sicart's (2008) definition of game mechanics, for the most part game mechanics can be split into three separate categories.

Core mechanics are mechanisms that are repeatedly used throughout a game environment by an agent in order to complete an overall objective of the game or achieve an "end-game state" (Sicart, 2008). In essence, these can be described as basic, commonly available mechanics; moving forward, backward, and left to right in a first person shooter such as in Infinity Ward's Modern Warfare 2 can be considered a core mechanic because without movement the player cannot accomplish any of the goals of the game's single or multiplayer campaigns. The same could be said for looking around and jumping, which are additional actions that can and sometimes need to be repeatedly used in MW2 (2009) to accomplish goals and achieve an end-game state. Other examples of core mechanics could include the gathering of resources in a real-time strategy game; a common aspect of the genre, this action in conjunction with other mechanics (described below) gives players the means in which to defeat opponents or complete objectives through spending those resources.

Primary mechanics can be understood as core mechanics that can be directly applied to solving challenges that lead to the desired end state. They are "readily available, explained in the early stages of the game, and consistent throughout the game experience" (Sicart, 2008, p. 10). Like core mechanics, primary mechanics are always available to the player, but usually with the exception of a basic requirement (or requirements) being met first. In order to fire a weapon and attack opponents, a primary mechanic in Modern Warfare 2, a player must first have one equipped in order to engage in this action (Infinity Ward, 2009). Some primary mechanics may also require the use of core mechanics at the same time; Electronic Arts' survival-horror game Dead Space, for the Xbox 360, Playstation 3 and PC, has an example of a game mechanic that includes this type of prerequisite. In the game, the player (as engineer Isaac Clarke) is faced with the task of defeating a variety of undead monstrosities called 'necromorphs', who can only be killed by using "strategic dismemberment" (Pellet, 2008) to remove the limbs of attacking enemies (EA Redwood Shores, 2008). The player can use the commonly available core mechanics of looking and aiming in the game, and provided, they have a weapon equipped, also use the primary mechanics of dismembering to defeat enemy necromorphs in order to progress and complete objectives (and therefore the game).

Secondary game mechanics are any kind of mechanism that can "ease the player's interactions with the game towards reaching the end state" (Sicart, 2008, p. 10), but aren't necessarily needed or are only available during certain points within the game environment. They may also only be available for use in conjunction with primary game mechanics. While aiming and firing weapons at opponents is considered to be a primary mechanic in Modern Warfare 2 (2009), the player also has access to a short-range melee attack (using a combat knife) for use in dispatching enemies. The knife and its corresponding melee-attack could be considered a secondary mechanic as it is not required of players to use it solely for reaching an end-game state, and can be used in combination with the primary shooting mechanic of the game. And since it's a melee attack, only in certain circumstances, i.e., a close quarter's battle, can the knife be used to attack enemies. Dead Space (2008) also has a similar secondary mechanic available to the player; Melee-attacks can be performed to push enemies back or to injure them, however the melee option falls short of enabling the player to destroy attacking enemies as efficiently as does the primary mechanic of using weapons. The option is available to the player, but fits the criteria of being a secondary mechanic since it "cannot be used exclusively to solve the main challenges" (Sicart, 2008, p. 10) of Dead Space. In addition, several games in the Role Playing Game genre have multiple examples of secondary mechanics; in both Blizzard North's popular action-RPG Diablo II (200) and more recent post-apocalyptic-themed Fallout 3 (Bethesda Game Studios, 2008), there are secondary mechanics in the form of optional 'side-quests' outside of the main story objectives of the game either presented alongside the main objectives or needing to be 'found' by the player. Players are not required to complete side-missions in order to reach an end-game state, but in doing so, can earn rewards through the form of RPG standards such as unique items or additional experience. This allows the player to use optional quests as secondary mechanics to assist them in their interactions with the main objectives of the game, but not requiring it of them.

Currently, most varieties of games on the market today try to include multiple game mechanics from all three categories within their design. However, given the complexity of games on the market today versus games developed one or two decades ago, it could be argued that the concepts of core, primary and secondary mechanics are no longer sufficient enough to contain all of the potentially definable game mechanics. Several of the best-rated games of 2009, such as Modern Warfare 2, Braid or Empire: Total War (Dietz, 2009) all include game mechanics that could potentially fall beyond the three categories discussed previously, and the vast number of mechanics used in games with expansive game worlds such as Fallout 3 or Grand Theft Auto IV could lend weight to the argument that some constructs of game mechanics are useless (Sicart, 2008). More detailed analysis of this concept is needed but is outside the scope of this thesis.

Mechanics Analysis

The heart of the gameplay design in the document is the mechanics analysis section. It is equally important for video games, board games, major AAA titles, indie games, and class projects. Pen-and-paper RPG manuals, such as the AD&D Player's Handbook, give a good idea of what the mechanic descriptions in this section should look like. Economics textbooks give good examples of how to analyze, model, and balance mechanics.

Mechanics, also known as game mechanics, are small groups of rules that outline a strategic conflict, inspire a particular emotion in the player, or move the game forward. They are perhaps best understood through some examples.

Racing is a classic mechanic. Get to the finish line before your opponents. Racing puts time pressure on the player, creating stress and motivation. It is inherently both fair and balanced; the achievement scale is defined by the ratio of fastest to slowest racer. The racing mechanic need not be as explicit as cars on a track. For example, in a capture-the-flag game, a race mechanic begins as soon as a flag is taken and both sides are trying to reach the goal (or intercept the carrier) as fast as possible.

Shooting is a popular mechanic. It involves reflex actions, strategy in setting up a shot before the enemy appears, and leading the target when projectiles are slow. Shooting doesn't have to involve guns. Various games have used shooting mechanics to fire oneself out of a cannon, take pictures of wildlife, or successfully throw and catch a ball in sports.

Describe the mechanics in your game. Mechanics are typically shared between large numbers of games and are the primary definition of genre. Indicate what other games use similar mechanics and describe the differences. Motivate the gameplay reason for each mechanic. Does it prevent an undesirable strategy, simulate some aspect of the game's setting, or exist to deepen strategy in an otherwise too simple game? Explain alternative mechanics that could have been employed to address that need and why this one is better. What is the strategy that arises from the mechanic?

Give guidelines for making the mechanic balanced and useful for gameplay. Support these arguments in text, graphs and diagrams, and probability and mathematics.

Other common mathematical tools for evaluating and balancing mechanics are outcome matrices and unit databases. Outcome matrices are for evaluating competitive situations where one kind of unit is up against another kind. The matrix lists the first unit type along the rows and the second unit type along the columns. Each entry in the center describes the outcome for the combination of unit types (think of a multiplication table from school or a road map that shows the distance between cities). Unit databases are tables with the unit types listed down a column and adjacent columns describing their statistical properties, like hit points and movement speed.

For each measurable property of the game (e.g., points, gold, health), give a target graph of how it should ideally vary over time. See Chapters 7, 8, and 10 for further discussions of the mechanics analysis section.