Persistent Game Worlds

Game worlds that exist independently of players' game and play sessions.

Through having people or servers dedicated to them, some games can have game worlds that are always available for players to enter them. This means that these Persistent Game Worlds exist independently from players' game and play sessions. This does not necessarily mean that everything that happens in them affect its future, parts of the entirety of them can be reset but this does not change that they are available continuously (with the exception for temporary server restarts).

Examples

Each Tabletop Roleplaying Game (e.g. Call of Cthulhu and Hârnmaster) spawn many different Persistent Game Worlds as game masters start campaigns. These game world can easily survive changes in player composition and even changes in whom does that game mastering.

MUDs (e.g. Kingdoms and DragonMud) and Massively Multiplayer Online Games (e.g. Ultima Online, World of Warcraft, and Entropia Universe) have complex and dynamic Persistent Game Worlds where players' game sessions with a single character can last for years. Minecraft servers supporting several players can be created with similar properties. Similarly, Massively Single-Player Online Games such as FarmVille continue updating for all players regardless of which players are playing. The life time of game instances for these kinds of games are mainly determined by how popular or commercially successful the games are, and these Persistent Game Worlds can even survive software generations.

Alternate Reality Games such as Prosopopeia and Conspiracy for Good hide in the real world and thus makes it part of them. This of course means that these parts continue to exist independent of game and play sessions.

Using the pattern

Persistent Game Worlds are basically Game Worlds that have Dedicated Game Facilitators maintaining them so they are available when players wish to enter them. This is most easily done by computer Game Servers but human Game Masters can also provide this service, although the accessibility may be more restricted and this adds Excise for them. The latter is the norm in tabletop Roleplaying games such as Call of Cthulhu and Hârnmaster although players often help with some of the task involved. Persistent Game Worlds make most sense for Multiplayer Games, especially Massively Multiplayer ones, but are also needed for Massively Single-Player Online Games that are Tick-Based or support Visits.

One typical requirement of Persistent Game Worlds is to keep track of Characters and Game Items, but not all Game Items need to be persistent (e.g. Power-Ups). For Tick-Based Games this means updating them whether or not players interact with the game system between ticks. This may include activating Resource Generators and Spawn Points but this may also require other functions to avoid creating too many instances or to Encourage Return Visits more frequently. The latter can for example be to have Budgeted Action Points that are Regenerating Resources which replenish over time. The handling of Resource flow needs to be handled for other purposes as well, including balancing the value of the various kinds of Resources against each other and ensuring that there are not too little of any type. This means considering overall how Producers and Consumers can interact in Producer-Consumer chains to create Emergent Gameplay, and how specific issues such as Spawning and Crafting should be handled. One solution is to try and create Closed Economies (which was tried for Ultima Online but didn't find a stable equilibrium) or a Faucet/Drain model (e.g. World of Warcraft or FarmVille). In general, Persistent Game Worlds need to have all Resources as Renewable ones rather than Non-Renewable ones.

Existing independently of players' play sessions is rather pointless if players need to synchronize when they should all interact with the Persistent Game Worlds. For this reason, use of the pattern implies supporting Late Arriving Players and Drop-In/Drop-Out gameplay. This also makes Persistent Game Worlds partly support Asynchronous Gameplay with all the requirements and possibilities on gameplay actions that this can have. Private Game Spaces strengthens this since it limits the amount of interaction possible between the players. While the Freedom of Choice to play may lessen the feeling of having to play these games, Construction and other forms of Creative Control (up to making the worlds Player Constructed Worlds) can increase the wish to play them since the creations continue to exist after the players' play sessions end; that is, they can provide players with a Value of Effort sensation. Although games with Persistent Game Worlds may easily have enough skill requirements to support Gameplay Mastery and can let players play long enough to develop it, this ability to train may make it difficult to provide Higher-Level Closures as Gameplay Progresses for these players without resolving to Red Queen Dilemmas. This can to some extent be countered by Grinding but risks making players lose a sense of Value of Effort. MUDs such as DragonMud and Kingdoms introduces Construction and other forms of Creative Control to these expert players to provide Varied Gameplay and thereby other types of possible closures. Other types of Varied Gameplay can be introduced by Dedicated Game Facilitators through Expansions or Evolving Rule Sets for similar reasons.

Nearly all Multiplayer Games have some possibility for Social Interaction but Persistent Game Worlds let these interaction develop over time. This allows for formalized structures such as Guilds to appear if supported, as well as informal ones such as Game-Based Social Statuses and Internal Rivalry. These various forms of Social Interaction may often be the main source why games with Persistent Game Worlds have Encouraged Return Visits - this can be increased by design options such as Altruistic Actions, Delayed Effects, Development Time, Events Timed to the Real World, and Delayed Reciprocity. Encouraged Return Visits can also be constructed from Ephemeral Events but only if players are aware of them, e.g. through Extra-Game Broadcasting or by being seasonal.

Given the many aspects of Resources, and possibly Construction or Character Development present in Persistent Game Worlds, there are often opportunities to include Trading in the design, both in-game and as Extra-Game Actions with Extra-Game Consequences. For games with Game Items is may be more or less impossible to avoid Game Element Trading, and through this Purchasable Game Advantages although in the latter case the game facilitators can be the sellers of the Game Items.

Diegetic Aspects

As mentioned below in the section of narrative aspects, Persistent Game Worlds can have problems with Thematic Consistency unless using Never Ending Stories.

Narrative Aspects

Games with Persistent Game Worlds cannot have fully Predetermined Story Structures but must instead rely on Never Ending Stories, or accept to break the Thematic Consistency by Spawning Quests and Instances that contain small Predetermined Story Structures. Providing the content of Never Ending Stories may be left to the Randomness of Resource Generators used (arguably used in Minecraft), Game Masters, or the players through giving them Creative Control for this through Storytelling. This kind of Storytelling is usually based on the players doing Roleplaying with their Characters and as the Storytelling does not have an immediate effect on the state of the Game Worlds, worlds supporting this type of gameplay typically generate significant amounts of Extra-Game Actions and Extra-Game Consequences.

Related to the developing of a narrative is if the events caused by gameplay have persist or simply get removed due to Spawning. While some games like Minecraft support the former through Persistent Game World Changes this is difficult to combine with re-occuring Quests in Massively Multiplayer Online Games like World of Warcraft. Player Constructed Worlds are also typically easy combined with Persistent Game World Changes as are games with human Game Masters. Although supporting these permanent changes pose problems with generating content these changes are at the same time often necessary for Creative Control to have a Value of Effort.

Consequences

Persistent Game Worlds can encourage players to view Character Development, and especially Player-Planned Development, as Investments having a Value of Effort that they feel Ownership of, this since these can be developed over a long period of time and there is no predetermined point in time when they will stop being valuable. By doing so, the persistence of a Game World may change how Roleplaying is conducted (e.g. not taking the risky chances often since the law of averages will make this a bad strategy). Examples of these kinds of attachments are common in games such as Ultima Online or World of Warcraft that have strong foci on Characters, but do often spill over to Factions or what is created through Construction (examples of that latter can be found in FarmVille and multiplayer servers for Minecraft). In general, these effects are strengthen the more Creative Control players are given up to the level where the worlds are Player Constructed Worlds.

The support for Late Arriving Players and Drop-In/Drop-Out gives players a Freedom of Choice when to play games with Persistent Game Worlds, especially when they contain Private Game Spaces. However, this may be countered by Encouraged Return Visits. Even if Persistent Game Worlds can provide Drop-In/Drop-Out gameplay, this does not automatically translate to a support of Interruptibility since players may be negatively affected by not participating in the game.

When the Investments players have done in Persistent Game Worlds are recognized by other players as having Value of Effort this can lead to the Extra-Game Actions of Purchasable Game Advantages, that is the Game Element Trading of Characters and Game Items using real world currencies.

Since Persistent Game Worlds need to either maintain the effects on Game Items or the Development that Characters have had, it is impossible to have full Reversibility in Persistent Game Worlds and they typically strive to have Temporal Consistency. This also means that small effects tend to escalate over time. Because of this it may be very difficult to avoid Emergent Gameplay of some sort and possibilities for Crafting, Abstract Player Construct Development, or Character Development can easily lead to ruining Player Balance.

Persistent Game Worlds can initially support Game World Exploration just as well as other Game Worlds, but for the same reasons as above the need for this decreased as gameplay time accumulates. This is however not the case in games that combined the pattern with either Evolving Rule Sets or Expansions (as for example World of Warcraft does).

Relations

Can Instantiate

Asynchronous Gameplay, Emergent Gameplay, Excise, Extra-Game Actions, Extra-Game Consequences, Freedom of Choice, Game-Based Social Statuses, Internal Rivalry, Social Interaction, Temporal Consistency, Trading,

with Altruistic Actions, Delayed Effects, Delayed Reciprocity, Development Time, or Ephemeral Events

Encouraged Return Visits

with Budgeted Action Points and Regenerating Resources

Encouraged Return Visits

with Character Development or Player-Planned Development

Investments, Value of Effort

with Construction

Value of Effort

with Construction or Creative Control

Varied Gameplay

with Evolving Rule Sets or Expansions

Game World Exploration

with Game Items

Game Element Trading, Purchasable Game Advantages

Can Modulate

Characters, Character Development, Factions, Game Items, Game Worlds, Massively Multiplayer Online Games, Multiplayer Games, Player-Planned Development, Roleplaying, Resource Generators, Spawn Points, Tick-Based Games

Can Be Instantiated By

Dedicated Game Facilitators, Game Masters, Game Servers

Can Be Modulated By

Closed Economies, Construction, Consumers, Crafting, Creative Control, Drop-In/Drop-Out, Encouraged Return Visits, Ephemeral Events, Expansions, Faucet/Drain, Grinding, Guilds, Instances, Never Ending Stories, Late Arriving Players, Persistent Game World Changes, Player Constructed Worlds, Predetermined Story Structures, Private Game Spaces, Producers, Producer-Consumer, Purchasable Game Advantages, Quests, Regenerating Resources, Renewable Resources, Roleplaying, Spawning, Storytelling

Possible Closure Effects

-

Potentially Conflicting With

Higher-Level Closures as Gameplay Progresses, Interruptibility, Non-Renewable Resources, Predetermined Story Structures, Reversibility, Thematic Consistency

Player Balance when Crafting, Abstract Player Construct Development, or Character Development exists in the game

History

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

Acknowledgements

Peter Lönnqvist