Rooms and Worlds

coherence provides two types of spaces where realtime gameplay can happen: Rooms and Worlds. In addition to these, Lobbies provide functionality for players to meet before a match, and to chat.

Rooms

Rooms are best for session-based gameplay where the match between players takes place in a short-lived environment. You can use the Online Dashboard to configure Rooms.

Use case

A good example is a first person shooter multiplayer match. The match takes place between two teams in a single game session, and players enter through a lobby and matchmaking. When the match is concluded, the multiplayer environment the match took place in (the Room) is closed and players return to a lobby.

This is one example of how Rooms can be used, but it is by no means the only use case. The important distinction between Rooms and Worlds (see below) is that Rooms are relatively short-lived and are meant to be created and closed by the Game Client through the coherence SDK.

See Rooms API.

Worlds

Worlds, as opposed to Rooms, are longer-lived and permanent multiplayer environments provided by coherence. Using the Online Dashboard, your project will easily define and manage your World configurations.

See Worlds API.

Use case

A good example of a World is a permanent environment for an Massively Multiplayer Game (MMO). Regardless of the number of players connected, the environment is always available, and players can connect and disconnect at will.

Entities can be permanently saved in the World so that even if there are no active connections, they still persist when players do connect.

Note that upon shutting down the World or restarting its Replication Server, the state of persistence is lost under current implementation.

Rooms and Worlds together

Your project does not have to choose one or the other. A project in coherence can contain both World and Rooms.

The primary difference in the configuration and usage of Room and Worlds is that Worlds are managed in the Developer Portal, whereas Rooms are created and managed through the SDK.

Use case

A good example of this scenario is again, our MMO. Although players connect to a permanent and persistent World, they may enter a dungeon instance with other players. These dungeon instances can be Rooms.

What about Lobbies?

In coherence, Lobbies work slighlty differently than Rooms and Worlds, and in fact they are not run by a Replication Server.

Lobbies are a convenient way to do matchmaking between player accounts, filter players based on their attributes, and provide a way for them to communicate among each other.

For more info, you can read the Lobbies section.