Actions that can be interrupted before their effects on the game state have been completely taken place.
Just because players have performed, or started to perform, actions does not mean that they will affect the game state. Games that allow actions to be interrupted before they affect the game state, either partially or fully, have Interruptible Actions.
Fighting games such as the Tekken series allow players to block opponent's attacks, effectively making the attacks interruptible.
In RoboRally, players choose how their robots should move by deciding a sequence of programming cards. These are the actions the robot will perform, but since other robots' movement may push the robot around, the intended actions are interruptible.
Several actions in the Left 4 Dead series, e.g. healing other players or helping them up when they are hanging from a ledge, can be disturbed by attacks of the enemies in the game, the infected.
Using the pattern
In Real-Time Games, Interruptible Actions are either Extended Actions, so that the actions can interrupted before their effects takes place, or actions with Delayed Effects (e.g. some cases of Capture) so that other actions may nullify the effect of the action. In Turn-Based Games, Turn Taking can in itself make Extended Actions interruptible but if actions can be interrupted during the acting player's turn special Turn Taking sequences may instead be necessary to describe in rules for how actions can be interrupted, even though these sequences may not be used for most turns. When the effects of the Interruptible Actions take so long time to materialize that they support Encouraged Return Visits, they force players into Risk/Reward calculations on how long they can stay away from the game.
While the name Interruptible Actions implied that it is the actions of Agents that can interrupted, the pattern can also be used to interrupt the progress of series of events, e.g. Scripted Information Sequences, controlled by the game system. Actions that cause Irreversible Events can be modulated with Interruptible Actions so that a period of time exists for agents to stop the action. This can provided Balancing Effects in games, e.g. fighting games where players can block attacks or interrupt Combos, so not only the actions available and how they are performed are important but also how one counters them.
Being able to interrupt an action can be a Privileged Ability. This is most common in card games but can also be found in situations where judges are used to modulate Negotiation. Depending on the game, it may be allowed to interrupt Storytelling and this can be used to make the story into a collaborative action.
Performing Interruptible Actions quite naturally provides players with an Anticipation, but can also create Tension since it may not success due to the influence of others and ruin the Value of Effort regarding the already invested effort. The Tension can be increased if the acting player is temporarily unable to affect the gameplay through Downtime or Turn Taking. When the action interrupted is part of another player's turn, this makes the pattern Interruptible Actions be a modulation of how Turn Taking is done.
Interruptible Actions are Ephemeral Events in that they exist only until the action is completed, and they provide Ephemeral Goals in that they can be interrupted but only for a short time. As completing an Interruptible Action can be a goal in itself, all Interruptible Actions spawn Interferable Goals. When the Interruptible Actions only are so until their Development Time has passed, this creates Time Limits for those trying to interrupt them. In a case where players have multiple Focus Loci, Interruptible Actions that are also Extended Actions may require players to perform Risk/Reward choices on how much Attention Swapping is necessary to ensure completion of the actions.
Making Extended Actions into Interruptible ones is a form of Balancing Effect as long as the Extended Actions are more powerful than other types of actions. If can be a Balancing Effect in another fashion also; it allows a means for players to Beat the Leader. It also increases Tension more and gives the Continuous Goal of completing the actions once one has started.
Since many actions are also Abilities, making an action into an interruptible one is likely to modify an ability as well.
with Development Time
with Extended Actions
Can Be Instantiated By
Can Be Modulated By
Possible Closure Effects
Potentially Conflicting With
An rewrite of the original pattern named Interruptible Actions in the book 'Patterns in Game Design' (Björk & Holopainen, 2004).
Björk, S. & Holopainen, J. (2004) Patterns in Game Design. Charles River Media. ISBN1-58450-354-8.