From gdp3
Jump to: navigation, search

Disposable game elements under the control of the game system or players that are either interacted with on a group level or have no individual distinguishing features from a set of other game elements.

Units is the term for game elements whose influence on gameplay is often considered from a group perspective, and whose uniqueness is not relevant for said gameplay. The Units may have different actions and attributes associated with them but as players controls or interacts with many Units simultaneously, the loss of single units is seldom the cause of losing a game.


All the pieces in Chess and Stratego (except the king and the flag respectively) are Units since there is no difference between members of the same category (e.g. Rooks, Bishops, and Pawns) and any may be lost without that causing the game to be immediately lost. In Bloodbowl, players control teams playing a version of American football in a fantasy setting and the team members (except star players) start indistinguishable from each other.

In the board game Space Hulk, one of the players controls an essentially unlimited amount of Units, called genestealers, which are replenished endlessly. The opposing player has a preset number of Units, called space marines, which are not replenished once lost. The X-COM series and the Jagged Alliance series are examples of computer games putting players in charge of small groups. In contrast, roleplaying games such as Dungeons & Dragons have players controlling one character of their own but these are typically outnumbered in combat situations by inferior enemies controlled by game masters.

Computational power makes it possible to have large amounts of Units in a game, but typically do so by letting them be only partly under the players' direct control. Pik-Min, a more or less real-time puzzle game, and Lemmings are examples of games that make heavy use of Units and the goo balls in World of Goo can to a lesser extent be seen as an example as well. Real-time strategy (RTS) games such as the StarCraft series and the Age of Empires series make heavy use of Units, where the choice and use of the different available types of units is one of the strategic skills of the games. The Defense of the Ancients series is similar, but players have no control over the Units (referred to as creeps). Computer can of course also be used to expose players to many enemies - this is especially common in zombie games, e.g. the Left 4 Dead series, the Dead Rising series, and Zombiepox.

Using the pattern

A stereotypical Unit in a game is a Diegetically Tangible Game Items or Generic Adversaries that can perform Movement actions, some other type of action affecting other Units or the environment (most often related to Combat), and which others can Eliminate through giving it Damage. A basic requirement for Units to exist is that the game system or the players have control over more than one game element, since having only one game element gives rise to the Avatars patterns instead. The patterns are however compatible, as for example in Defense of the Ancients where each player in a Team has a Character but have no control over the many creeps that also fight on their side. Units can be used also as Companions to the players' Avatars (or Characters); in this case, they can be given various degrees of autonomy or be directly controlled through the Avatars. For games using Line of Sight, a basic decision regarding this is if Units should block Line of Sight or not.

Several design choices have to be made when using Units. Maybe the most fundamental is if the units are supposed to be under players (including AI Players) control or be under control of the game system. Their prime use when directed by the system is to be Enemies, and their behavior is in this case the result of being Algorithmic Agents or having Game Masters. The agency can also be used to make Units take some Initiative, e.g. so that Units in Warcraft or StarCraft attack enemies found after having moved to a location specified by a player. The complexity and skills of these Units can be designed to support both Casual Gameplay and Challenging Gameplay, especially when used as Companions and Enemies respectively. Quite often these types of Units have clearly different modes the operated in, for example going from a passive to active mode when an Alarm is triggered.

The amount of Units available to players is also one of the most fundamental choices. The number of the Units may be preset so that the players have Limited Resources or it may be determined by Randomness, or depending on the player actions, during the set-up phase. When the players can affect the number of Units they may have during the gameplay through Construction, these Units are Renewable Resources put into gameplay through Game Element Insertion. In other cases, the Units may instead be Non-Renewable Resources. New Units can be rewards for completing sub goals, be produced from Resource Generators or Converters that are under players' control, or be acquired through succeeding with Gain Ownership goals of enemy Units through Transfer of Control actions. The Units themselves may be part of neutral pools of Resources, which players can take control over through succeeding with Gain Ownership goals. In most cases, the lifetime of Units is governed by a Producer-Consumer pattern. For example in the Civilization series, the production of Units is done in cities, and the Units can be consumed in Combat through Game Element Removal. Using Converters, or gaining control over new Producers, may allow players to Upgrade Units to give them Improved or New Abilities. When New Abilities as given to the Unit classes, this give players as a whole New Abilities while when done on individual Units instead created localized Orthogonal Differentiation but may turn Units more into Characters than Units. Competence Areas for Units may arise from providing them with New or Improved Abilities but this may also be achieved simply by making several different types of Units available. Resource Caps can be used to limit the maximum number of Units available, and by this hindering one form of Positive Feedback Loop related to simply out producing opponents.

Beyond how many Units are available to players is the decision of when the players can start to use them. Making all possible Units available at the start makes them a Non-Renewable Resource and typically speeds up the game if they can be eliminated during gameplay. Portioning the available Units over time or giving them out as rewards for goals can be used to maintain Casual Gameplay and avoid Analysis Paralysis. Alien Space Bats can be used to motivate the introduction both of individual Units but also completely new types of Units during gameplay. In games with Resource Caps on the populations of Units, increasing or decreasing the number of Units allowed can be used as Rewards or Penalties. The number of Units can also be regulated by Game Element Removal, for example through being targets of the Damage from Traps and the Combat motivated by other players' Eliminate goals. Given that they can be present in large number, the destruction of Units or giving them Decreased Abilities does not need to be game breaking events.

The Abilities and Attributes (e.g. Health) of Units can either be identical - in order to stress the use of them as a group - or be Asymmetric to encourage Strategic Knowledge related to Combos (most efficiently promoted through Orthogonal Differentiation). In the latter case, this can increase the value of each Unit as it may not be replaced by another and may promote Stimulated Planning on when and where to use uncommon Units. If the players can control the production of Units, the existence of several different types can promote Varied Gameplay and Trade-Offs, as the players have to decide what types of Units they want to acquire. Although the types of actions Units may have can vary widely, unless Movement or Combat is possible for them they are likely to be interpreted more as Tokens than Units (especially if their other actions do not have some directional component). An example of this can be found in Small World where Units are placed through Tile-Laying rather than by being moved individually; this makes the Units be somewhat more like Tokens. Privileged Movement can be used to modulate Movement further, e.g. to provide access to Safe Havens. However, Combat is a very common ability, even more so than for Avatars, and make it possible to have Capture and Eliminate goals. When Units are to be able to do more than one action per turn, Budgeted Action Points are a common solution and varying how many action points Units have is yet another was to give them Asymmetric Abilities. Invulnerabilities and Vulnerabilities is two other options for making Units have specific differences, most often related to Combat but sometimes also to Movement. Although uncommon, combining the two make it possible to give Achilles' Heels to Units.

Diegetically Tangible Game Items and Obstacles can both be used to influence the possible Movement of Units. The Units themselves can also be Diegetically Tangible Game Items and are then Obstacles to each other, and in Wargames it is common to modify them by giving them Zone of Control abilities (this is also done in the Civilization series). Environmental Effects can also affect Movement but just as well provide Privileged Abilities. The game Lemmings is a good example of how the Movement of Units can be modulated: using both Environmental Effects and Obstacles, and having the Lemmings as Diegetically Tangible Game Items. Laning is another way of modifying the Movement of Units, here by creating multiple different lanes which the Units use to move towards a goal area.

The value of units relative to each other is also worth considering. This may typically affect the cost to create them with Producers and be linked to their power, especially if the Units have different Limited Set of Actions available or if any Privileged Abilities exist. For game designs that make use of Line of Sight, this is a possible area of providing varying levels of abilities. The different abilities of Units do not have to be inherent; the use of Controllers or Tools can explain various Privileged Abilities as can Location-Fixed Abilities, e.g. Alarms, while Vehicles can explain Privileged Movement. Orthogonal Differentiation between Units may be used to set up Paper-Rock-Scissors power relations so that some weak unique can be powerful in special cases. This is for example done in Stratego, where the weakest Unit, the spy, is the only type to be able to kill the most powerful one, the Marshal. This evens the usefulness of the Units even though they have varying power, and typically also provides more Varied Gameplay.

Looking at a larger perspective, the availability of different types of Units can actively create different gameplay phases and indicate shifts from one to another. For example, Game World Exploration may be only allowed to those with Privileged Movement while those that can construct Bases or Installations may be needed for Expansion. Continuing, Exploitation can be encouraged through Units good at collecting Resources and availability of Units with the best Combat abilities suggest a shift to Extermination phases.

Providing players with sufficient information about the current state of the Units can require either Geospatial Game Widgets to provide information, e.g. their Health, co-located with the Units or the use of Game State Overviews (or a Game World that can be viewed in its entirety all at once). Many games using Units, and especially those where the number of the Units can change over time, make use of a Camera for Third-Person Views, and God Fingers to allow players to navigate Game Worlds in order to locate and select which Units to use.

Units typically have no Characters associated with them since they are most often meant to be indistinguishable from each other. However, the patterns can be combined when most of the player interaction with the Units are on the group level but some individual management occurs intermittently. The X-COM series and the Jagged Alliance series are examples of this. It is however more common that Units are affected by Abstract Player Constructs, either on a individual level to handle a limited range of information (e.g. health, experience, and promotions in the Civilization series) or as modifications due to a country's or civilization's technology level (e.g. modifications of Unit attrition in the Victoria series). Allowing the Naming of Units, e.g. ships in the Europa Universalis series, can be seen as a minimal change to Abstract Player Constructs but can also be used to help ease Micro Management.

Many of the aspects of Units, including the numbers available and which abilities they should possess, can be put partly in a player's control by using Heterogeneous Game Element Ownership so they themselves choose which Units they should have.

Diegetic Aspects

Units that have different abilities are typically distinguished from each other through use of Diegetically Outstanding Features - this to help players understand the game state and more easily navigate to specific units.


Units are common solutions to the problem of having the Thematic Consistency of many individuals or groups that together work towards a goal - but this Thematic Consistency also restricts their appearance and behavior. Units which are under another player's or the game system's control are typically examples of Agents. If compared with single Avatars with the same action repertoire, Units allow a greater Freedom of Choice simply because a choice can be made for each Unit. In addition, having several game elements that can be controlled can allow Combos or Collaborative Actions which would be impossible otherwise, but this may require Attention Swapping. They typically also function as a Limited Resource that can be used to achieve gameplay goals; Avatars and Characters cannot be used in this way although their Lives and Health can. As a potential downside to these effects, having many Units often requires more input to the system which can in effect become Excise. This is especially true in Self-Facilitated Games. In Multiplayer Games that are also Turn-Based Games they may cause Analysis Paralysis, partly because they add complexity and possibility for Combos but also since they provide a form of internal Turn Taking if the movement and actions of each Unit is considered a turn.

Units are Resources in games, and one example of this is that each of them can be a point to disperse Fog of War. For this reason, acquiring or constructing them represents a form of Investment in a Abstract Player Constructs that lead to Abstract Player Construct Development.

For this reason, players controlling Units that are in some form of danger to receive Penalties related to these have the Continuous Goals of trying to Survive, especially when the Penalties for losing Units include Ability Losses and the ability to perform Combos. When the Penalties can be avoided by Movement this results in players having Evade goals. Units with Achilles' Heels or Vulnerabilities can add extra motivation for players to engage in Conceal or Evade goals.

This of course happens in games with Avatars and Characters but since gameplay may continue when Units are lost, or the consequences are not so severe, players may need to live with those effects rather than restarting the game or entering Save-Load Cycles. Units are not only affected by the possibility of Ability Losses in games; they modulate Ability Losses since they may make the Abilities into Limited Resources.

Units allow the players to have multiple Focus Loci where they can affect Game Worlds without breaking their Diegetic Consistency. However, they may create Complex Gameplay due to demands of Attention Swapping. This is especially likely if the game does not have Game State Overviews which shows relevant information about each player's Units, or if the game does not provide enough information through Geospatial Game Widgets about the Units so that players need to select them to get the information.

Various Units can have different Limited Set of Actions by making use of Orthogonal Differentiation, so using them can require the players to make Trade-Offs between different types of Units. Different stages of the gameplay can further require different types of Units, allowing Varied Gameplay as do games using Paper-Rock-Scissors power structures between the different types of Units. Creating a good set of Units that work well together can be seen as Construction besides the activity of constructing individual Units.

Units let the players simulate Teams even in Single-Player Games as they can let Combos appear to be Team Combos. This encourages Stimulated Planning and allows players to do Resource Management on a higher level than using Avatars, as the destruction or death of Units may in some cases even be advantageous and necessary. Thus Units can be seen as a use of Parallel Lives which in contrast to Avatars are more or less dispensable.

Units have compatibility problems with the Non-Player Characters pattern since the former assumes both diegetic individuality and not being under player control.

Units are problematic to combine with Detective Structures since the be necessity provide players with several different viewpoints to Game Worlds.


Can Instantiate

Attention Swapping, Capture, Collaborative Actions, Continuous Goals, Combat, Combos, Companions, Complex Gameplay, Construction, Diegetic Consistency, Eliminate, Enemies, Excise, Focus Loci, Freedom of Choice, Gain Ownership, Investment, Limited Resources, Parallel Lives, Resource Management, Resources, Stimulated Planning, Survive, Thematic Consistency, Tile-Laying, Trade-Offs, Varied Gameplay, Fog of War

with Abstract Player Constructs

Abstract Player Construct Development

with Achilles' Heels or Vulnerabilities

Conceal, Evade

with Asymmetric Abilities

Strategic Knowledge

with Companions

Casual Gameplay

with Diegetically Tangible Game Items


with Enemies

Challenging Gameplay

with Movement and Penalties


with Multiplayer Games and Turn-Based Games

Analysis Paralysis

with New Abilities


with Self-Facilitated Games


with Single-Player Games


Can Modulate

Ability Losses, Expansion, Exploitation, Extermination, Game World Exploration, Game Worlds, Line of Sight, Turn Taking

Can Be Instantiated By

Generic Adversaries

Can Be Modulated By

Abstract Player Constructs, Achilles' Heels, Agents, Abilities, Ability Losses, Alarms, Algorithmic Agents, Alien Space Bats, Asymmetric Abilities, Attributes, Budgeted Action Points, Characters, Combat, Competence Areas, Construction, Controllers, Converters, Damage, Traps, Decreased Abilities, Diegetically Tangible Game Items, Diegetically Outstanding Features, Eliminate, Environmental Effects, Game Element Insertion, Game Element Removal, Game Masters, Game State Overviews, God Fingers, Geospatial Game Widgets, Health, Heterogeneous Game Element Ownership, Improved Abilities, Initiative, Invulnerabilities, Laning, Limited Set of Actions, Limited Resources, Line of Sight, Location-Fixed Abilities, Naming, New Abilities, Non-Renewable Resources, Movement, Obstacles, Orthogonal Differentiation, Paper-Rock-Scissors, Positive Feedback Loops, Privileged Abilities, Privileged Movement, Producers, Producer-Consumer, Renewable Resources, Resource Caps, Resource Generators, Safe Havens, Thematic Consistency, Third-Person Views, Teams, Tools, Transfer of Control, Upgrading, Vehicles Vulnerabilities, Zone of Control

Potentially Conflicting With

Avatars, Detective Structures, New Abilities, Non-Player Characters


A rewrite of a pattern that was part of the original collection in the book Patterns in Game Design[1].


  1. Björk, S. & Holopainen, J. (2004) Patterns in Game Design. Charles River Media. ISBN1-58450-354-8.