Capture

The elimination or change of ownership of an game element.

Many games contain events that remove game elements from play. Traditionally this is called to Capture the pieces, even if this may mean removing them or transforming them to so they become another player's pieces.

Note: While Board Games typically use the term Capture, Real-Time Games instead uses Eliminate. For this pattern collection, Eliminate is seen as a more specific form of Capture due to being a newer form of the same phenomena.

Examples

Board Games show many different ways to Capture enemy pieces: Hnefatafl by surrounding a piece from two opposing sides (four for the king), Go by completely enclosing an enemy group of stones, and Chess and Stratego by replacing a piece with ones own. It is also worth noticing that Go allows players to make their own groups be captured for larger tactical reasons while there exists specific rules for which pieces can Capture which pieces in Stratego.

Qix allows the player to catch computer-controlled units by enclosing them in the smaller area of the two areas that are created by outlining a path in the unmarked part of the game area.

Priests in Age of Empires series can convert pieces controlled by other players as their main offensive action.

Using the pattern

Three main decisions need to be done for each type of Capture allowed in games: which game elements can perform the Capture, which game elements can be the targets, and what actions are required to activate the Capture. Traditionally Units have been the game elements that can capture with rare appearances of Avatars through King pieces in for example Chess (Units will be referred to mostly in the following but unless explicitly noted this could be replaced by Avatars). Many games, e.g. Chess, Go, and Draughts, make no distinction of which game elements can Capture, but the Bombs in Stratego cannot move and therefore not actively try to Capture other pieces. Likewise, most pieces can be the target of Capture actions but Hnefatafl has special requires for capturing the king piece and Stratego as special rules for which Units can Capture which. Combined with the Imperfect Information in Stratego, this makes capturing there have an element of Risk/Reward.

Parlett describes in some detail 7 ways to Capture in board games: Custodianship, Displacement, Enclosure, Intervention, Leap, Approach, and Withdrawal. Custodianship consist of flanking a target by placing Units in Contact with it. This example of Combos can be found in ordinary Captures in Hnefatafl. Displacement is simply using Movement to enter the space occupied by the target and remove it, as is done for example in Chess. Enclosure, used in Go, requires placing Units in all spaces adjacent to the target or target group (the capture of the king in Hnefatafl can be seen as an example of this as well, or a double case of Custodianship). Intervention is the inverse of Custodianship but Parlett provides no examples. Leap is capturing by moving over the target, as for example is done in Draughts (line leaps allow several target to be capture simultaneously; long leaps do not require that either the starting or stopping space is adjacent to the target). Approach is capturing by moving adjacent to the target while Withdrawal is capturing by moving away from it (Parlett mentions Fanorona as an example of both). More ways are possible (e.g. Reflection and Telekinesis) but have rarely been used.

Even given one of these ways of Capture, the game design must support some action that facilitates it. In the case of Real-Time Games, this typically is Combat, Maneuvering, or Aim & Shoot, all that promoting skills in Dexterity-Based Actions. Turn-Based Games favor the use of Movement, promoting Puzzle Solving as well as Tactical and Stimulated Planning, but can also make use of Investment or Bidding. Real-Time Games usually has the subgoal of Contact (but Qix shows as an example of using Enclosure) while Turn-Based Games commonly have subgoals such as Alignment, Enclosure, Configuration, or Connection in additional to Contact.

Parlett also mentions Conversion, which is the Transfer of Control of a game element to another players and which can be used as a modifier to any of the Capture methods listed (Reversi is an example of this), and makes conflates Capture with Gain Ownership. Another possible modifier is Huffing, allowing Units that could have captured but did not to themselves be captured. Parlett also notes that a Capture can be immediate (the most common case), or be a Delayed Effect that can open up for making it an Interruptible Action (as is argued to exist by those reconstructing the rules of Ludus Latrunculorum).

The goal pattern Eliminate is a more specific form of Capture and typically used for Real-Time Games, especially those using Aim & Shoot. It can be used to instantiate Capture but using other means allows less aggressive diegetic explanations of why game elements are removed, and what happens to them after they are removed. Designing Capture can for most cases be seen as choosing between whether to use Eliminate or Gain Ownership, but can in both cases be seen as a struggle over Ownership.

Interface Aspects

To provide Smooth Learning Curves, game interfaces can use Game State Indicators to show which Units are under threat to be Captured.

Consequences

Capture goals are very often related to Overcome goals in the Hierarchies of Goals. It also typically causes Preventing Goals such as Evade for those controlling the targeted Units. The control of a new game element through Transfer of Control after a Capture can give New Abilities, possibly Privileged Abilities, but can also trigger retaliating Capture goals by an original owner to regain control. How all these related to each other depends primarily on their individual Reward structures and on players' tactics. However, since Units can typically Capture each other, all Units belonging to one players can work against another play and thereby work as Enemies.

Capture depends on Timing in Real-Time Games but for Turn-Based Games Puzzle Solving is more often required, as players have to take other Agents actions into consideration due to Turn Taking. Capture combined with Eliminate of game elements that are Non-Renewable Resources can quicken gameplay as fewer game elements remain and promote Higher-Level Closures as Gameplay Progresses since each element represents a greater part of players' Resources.

Quite naturally, successful captures can lead to Game Element Removal especially when Capture is instantiated through Eliminate.

Relations

Can Instantiate

Combos, Enemies, Evade, Hierarchies of Goals, Overcome, Preventing Goals

with Bidding, Movement, Investment

Puzzle Solving, Stimulated Planning, Tactical Planning

with Combat, Maneuvering, or Aim & Shoot

Dexterity-Based Actions, Timing

with Delayed Effects

Interruptible Actions

with Game State Indicators

Smooth Learning Curves

with Non-Renewable Resources

Higher-Level Closures as Gameplay Progresses

with Imperfect Information

Risk/Reward

with Transfer of Control

Gain Ownership, New Abilities, Privileged Abilities

Can Modulate

Ownership, Transfer of Control

Can Be Instantiated By

Alignment, Avatars, Configuration, Connection, Contact, Eliminate, Enclosure, Movement, Units

Can Be Modulated By

Aim & Shoot, Bidding, Combat, Contact, Delayed Effects, Game State Indicators, Investment, Maneuvering, Movement, Non-Renewable Resources, Risk/Reward

Possible Closure Effects

Game Element Removal

Potentially Conflicting With

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History

An updated version of the pattern Capture that was part of the original collection in the book Patterns in Game Design.

Acknowledgements

Karl Bergström, Martin Eriksson, Peter Ljungstrand