Games can be complex in many ways: requiring the understanding of many rules, being able to understand the consequences of immediate actions in the long run, or being able to plan many actions ahead. All these forms of complexity in games together give an overall complexity for every game, and for games to offer the right level of challenge---and the right type of challenge---the Right Level of Complexity needs to be achieved for the intended game design.
Example: The size of a Go board determines the number of possible combinations that a single game session can take and thereby the complexity of the game.
Example: Real-time strategy games and advanced simulations such as Europa Universalis II are only playable because computers can handle the complexity of the rules and interactions between huge amount of game elements. Some also allow players to modify how much complexity they should have to handle by offering ways of automating certain actions.
The Right Level of Complexity of a game depends on the intended gameplay style. Games that strive to have Cognitive Immersion through Stimulated Planning have higher complexity but also risk Analysis Paralysis. Games that wish to minimize the risk for Downtime among players or simply make the game easy to play usually have less complexity, but this may give Limited Planning Ability if the game also does not provide Predictable Consequences. The complexity of the game often also affects the influence players can have and thereby the Illusion of Influence they have. Effects of actions that require a certain level of complexity to be possible at all include Experimenting and Creative Control.
The level of complexity affects all types of actions, but the Right Level of Complexity can most easily be set for Rhythm-Based Actions, by increasing tempo or number of required actions, and Puzzle Solving, by increasing the number of game elements that need to be considered. Combos can be used to control the complexity in a game, since the difficulty of combining actions does not have to depend completely on the difficulty of performing the individual actions.
The prime way of modulating complexity is through modulating the number of game elements that players have to interact with or the number of relations between game elements that players have to consider. The relationships can easily become more complex through the use of Converters or Producer-Consumers, modulating the complexity of Resource Management. This information about the game elements can further be used to modulate the Right Level of Complexity through either Direct Information or Extra-Game Information.
Besides simply increasing the number of game elements or how they affect evaluation functions, complexity can be modulated through Attention Swapping, Indirect Control, or Ability Losses. Attention Swapping increases the complexity, as players must shift their attention from one area to another and create an impression of the local game state. Indirect Control is an example of how both the number of game elements and relations increase, since players need to consider both the game elements they control and those they do not control but can indirectly affect, as well as what relations the game elements have to each other. Ability Losses may not remove complexity but can make it irrelevant since players cannot affect it!
Another way to modulate the complexity in the game, which may or may not affect how difficult the game is to play, is through the Narrative Structure of the game. This can be done through Red Herrings and Role Reversals, and can make Puzzle Solving based upon the story more complex.
Having the Right Level of Complexity in a game usually strongly influences if the Right Level of Difficulty is achieved in a game design. When the complexity increases with the increase in player skill, providing the Right Level of Complexity gives the game a Smooth Learning Curve and thereby makes Game Mastery easier to achieve.
The Right Level of Complexity in a game can be one that gives Limited Foresight of long-term effects of actions even though they have short-term Predictable Consequences. This level of complexity supports Experimenting, and can promote Constructive Play, as it gives players a form of Creative Control within the vastness of potential game spaces given by the complexity of the game.
Instantiates: Cognitive Immersion, Constructive Play, Smooth Learning Curves, Experimenting, Creative Control, Game Mastery, Analysis Paralysis, Limited Planning Ability, Right Level of Difficulty
Modulates: Predictable Consequences, Limited Foresight, Stimulated Planning, Rhythm-Based Actions, Downtime, Puzzle Solving, Illusion of Influence
Instantiated by: Narrative Structures
Modulated by: Attention Swapping, Producer-Consumer, Red Herrings, Resource Management, Converters, Decreased Abilities, Perfect Information, Role Reversal, Ability Losses, Indirect Control, Extra-Game Information, Combos
Potentially conflicting with: