Units

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.

Examples

All the pieces in Chess and Stratego (except the king and the flag respectively) are Units since there is not 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.

Computational power makes it possible to have many Units in a game, even if they may only partly under the player's 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. Defense of the Ancients 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

Agents Freedom of Choice

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.

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.

Enemies Algorithmic Agents

The amount of Units available to players is 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, these Units are Renewable Resources and can be rewards for completing sub goals or be produced from Resource Generators or Converters that are under the player's control. The Units themselves may be part of a neutral pool of Resources, which the player 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. Upgrading Producers, or gaining control over new ones, may allow players to give New Abilities to their Units, as players may gain New Abilities as a whole through succeeding with Gain Ownership of enemy Units through Transfer of Control. Population 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 outproducing 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 the Right Level of Complexity and avoid Analysis Paralysis. In games with Population Caps, increasing or decreasing the number of Units allowed can be used as Rewards or Penalties.

The abilities of the 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 Unit 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 Tradeoffs, 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 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).

The values of units relative to each other is also worth considering. The may typically effect the cost to create them with Producers and be linked to their power and any Privileged Abilities. However, Orthogonal Unit 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

Providing players with sufficient information about the current state of the Units can require the use of a Game State Overview 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 a God's Finger to allow the players to navigate the Game World in order to locate and select which Units to use.

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.

Consequences

Alarms Real-Time Games Agents Avatars Algorithmic Agents Turn Taking Stimulated Planning Enemies Freedom of Choice Enforced Agent Behavior

Combos

Units are a form of Resource in games, and often acquiring them represents a form of Investment. Units allow the players to have multipleFocus Loci where they can affect the Game World without affecting Consistent Reality Logic. However, this may make it difficult to attain the Right Level of Complexity due to Attention Swapping. This is especially likely if the game does not support a Game State Overview, which shows relevant information about each player's Units. Units are often targets of the Damages from Deadly Traps and Combat motivated by other players' Eliminate goals, resulting either in the destruction of the Units or in Decreased Abilities of those Units. The Penalties of losing the Units are often Ability Losses, and the player controlling the Units may have Evade and Survive goals.

Various Units can have different Limited Set of Actions by making use of Orthogonal Unit Differentiation, so using them can require the players to make Tradeoffs between different types of Units. Performing the Attention Swapping between Units is most commonly enabled by another Focus Loci, a God's Finger. Different stages of the gameplay can further require different types of Units, allowing Varied Gameplay. The different abilities of the Units do not have to be inherent; the use of Tools can explain various Privileged Abilities.

Units let the players simulate Team Play so they can set up complex actions as well as Extended Actions by coordinating the individual actions of several Units. This allows Stimulated Planning and allows the players to do Resource Management on a higher level than using Avatars, as the destruction or death of the 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.

History

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