Games where the gameplay is clearly divided into clearly defined parts where players can plan and select actions
Many games separate gameplay into easily understandable units where some actions are allowed and others not allowed. Most traditional games follow this pattern by letting one player plan and then execute an action as a turn and then letting another player do a turn, alternating until the game is finished. Turns are in this way typically used to describe periods of gameplay when one player can plan without risk of interruption to select and perform one action. However, this can challenged in various ways in games while still having them be perceived as having turns, e.g. by having several players do turns simultaneously, being able to do several actions, introducing time limits to make the actions, or letting other players have the possibility of interrupting turns.
Games with more complex structures of organizing gameplay can have turn-like structures on many levels. To distinguish between these rounds, phases, and segments are often introduced as concepts, while turns typically signify when players make important choices that need several steps to evaluate or get to make an uninterrupted series of actions. The players' perception of the gameplay is often the determining factor if a game is called turn-based rather than its internal structure. This is the case why not all computer games have seen as turn-based, even if they do have clearly defined states at all points due to being programs.
In Chess and Go, the players take turns to move or place their pieces on the board. In the basic variant, there is no strict time limit for the players to execute their turns apart from social pressure exerted by the other player while in tournaments this may be enforced due to practical reasons. Diplomacy is an early example of letting players simultaneously have turns, alternating between letting them negotiate with each other for a predetermined period of time and then executing their chosen actions. Roborally is a newer example where players simultaneously decide the next five actions for their robots and then execute them in parallel. Ricochet Robots uses a similar structure, with each turn letting all players participate in a time-limited bidding in how few moves they can solve a movement puzzle, and then letting the lowest bidder show his or her solution in an proving phase.
The computer games Laser Squad Nemesis and the Combat Mission series offer the players modes for hot-seating, switching the player whose turn it is, and sending the turn information via e-mail to the other player. The Civilization video game series has a turn-based structure in which a player may move all his or her units based upon an action point system, showing an example of more complex division of how to separate gameplay. Bloodbowl does the same but enforces that one unit's actions are finished before activating the next unit.
The two-person board game Space Hulk also has a similar structure, but also has strict time limits on the player controlling the human marines. By introducing a time limited planning phase and an execution phase which replenishes the time limit, the single-player computer-based version can be seen as removing the turn-based structure since enemy actions also take place within the execution phase. Similarly, the board game Space Alert has a real-time planning phase followed by a execution phase when they are executed. By separating all the planning and all the execution into two phases, the game also challenges the turn-based structure.
Puerto Rico lets the active player chooses one action which then every player gets to perform, although the choosing player get a bonus. In this fashion, the game has a turn-based structure which is associated with one player but no player needs to wait long between being able to act in the game.
Wikipedia has a section on Turn-Based Games. The pattern Turn Taking discusses the effects of letting players alternate between being able to influence the game and different options on how to limit the actions possible within a turn.
Using the pattern
A primary choice when considering having turns in games is if this should be done in conjunction with Turn Taking or not, since this can give rise to Exaggerated Perception of Influence and Stimulated Planning as well as Downtime and Analysis Paralysis. Private Game Spaces is an alternative to allow Stimulated Planning but makes Combat more difficult and Conflict less direct. These consideration is of primary interest for Multiplayer Games since the "problems" of Downtime and Analysis Paralysis does not typically affect Single-Player Games.
An important aspect of Turn-Based Games is what determines how a turn ends. Besides simply waiting until a player has finished (see Turn Taking for options), one can introduce Time Limits which although not possible on an overall scale, shows how Turn-Based Games can have part that work like Real-Time Games. For the Time Limits to serve a purpose, failing to finish ones actions before the given time need to be connected to Penalties, which can range from enforced No-Ops through pre-determined or randomized actions to forfeiting the game. Another possibility is to have a turn end as a Penalty, e.g. used in Bloodbowl when failing to catch passed balls or critically failing when attacking.
Avoiding Turn Taking requires that rules exists concerning all players rather than just one player to determine when turns end. This can simply be when all players have finished their possible actions according to any of the possibilities above, but this also makes Downtime and Analysis Paralysis a possibility (although mostly mitigated if common Time Limits are used). However, some purely group-based alternatives exist. Firstly, where Bidding and Trading are typical examples, one can provide actions which have Diminishing Returns structures until all players prefer to do No-Ops. Secondly, which can be discussed if it avoids Turn Taking or not, one can let a player choose what type of action to do but then let all players in turn do that action (as in Puerto Rico). Thirdly, which is typically a consequence of all players just done Action Planning in a common turn, is to have a turn consist purely of Excise (found both in Diplomacy and Space Alert).
Regardless of Turn Taking, Time Limits effectively turn Turn-Based Games into Tick-Based Games. However, unless there are Dedicated Game Facilitators it is easy for extra moments of planning time before the next turn begins unless the players have divided some of their attention from the actual gameplay.
Turns are not always easy to explain diegetically. Possibilities include seeing them as actions and re-actions, e.g. attacks and defenses, or as ways to model specific parts of the diegetics while avoiding otherwise, e.g. combat in role-playing games such as Dungeons & Dragons or GURPS. Turns can however work well as the mechanic that progresses time in the game world, see Narrative Aspects.
The interface for games need to clearly indicate what actions are possible and which are not during any specific turn, and in many cases also show who's turn it is. This is actually even more important in Self-Facilitated Games since mistakes can be difficult to undo and may have revealed planned players actions, and some games provide special game tokens just to keep track of this (e.g. the governor card in Puerto Rico). In this way, the way turns are indicated in games are similar to how game modes are indicated. However, switching between game modes are typically voluntary (e.g. between a main interface and an inventory) while changes between different types of turns are results of game events.
Turns can easily be mapped to the progress of time to link gameplay to a narrative, and is commonly done in games with strategic or historic perspectives. These can have linear relations, e.g. each turn being half a year in Diplomacy or one hour in the Hearts of Iron series, or change as gameplay progresses as in the Civilization series. While the latter does so independently of the actual gameplay that has taken place, Origins does not make an exact mapping (it state that one turn is approximately 10,000 years in the rules but this is not kept track of during gameplay) but instead puts players in different developmental categories.
Many goals and activities are fundamentally different depending on if the gameplay is Real-Time or Turn-based. Combat and Capture in Turn-Based Games allow players to use more of their cognitive skills in compared to Real-Time Games, as they have more time to think, and the Timing of actions require more Puzzle Solving skills than skills in Dexterity-Based Actions.
Turn-Based Games can easily give rise to Downtime, especially in Synchronous Games, either due to waiting for other players in games with Turn Taking or, for Tick-Based Games, having completed their planning and actions well in advance of a fixed Time Limit. This Downtime can provide Stimulated Planning if the game supports Predictable Consequences or Private Game Spaces (e.g. Chess and Puerto Rico respectively), but the presences of Predictable Consequences can also be the cause of Analysis Paralysis in the acting player. These effects are often less drastic in Asynchronous Games than in Synchronous Games, as players have possibilities of non-gameplay related actions while waiting for other players to complete their turns. Those games without Turn Taking may have the consequences mentioned above, but is less likely to since all players as the start of a turn have something to do. A possible disadvantage is however that the same player may be the cause of Downtime repeatedly.
Turn-Based Games make Game Pauses easy to introduce since there are clear break points, and it is easy for every player to be aware exactly where in the gameplay one was when game is to be continued. For the same reason, they are the basis for most Asynchronous Games.
Can Be Instantiated By
Can Be Modulated By
Potentially Conflicting With
A revised version of the pattern that was part of the original collection in the book Patterns in Game Design.
- Wikipedia entry on Time-keeping systems in games
- Björk, S. & Holopainen, J. (2004) Patterns in Game Design. Charles River Media. ISBN1-58450-354-8.