Guardians is an open-source cooperative multiplayer game written by David A Smith using the Croquet Worldcore game engine.
It features massive numbers of AI bots, taking advantage of Croquet’s Synchronized Computation Architecture that uses only client-side code, and where additional bots do not incur additional network traffic or server load. From a Croquet programmer‘s point of view, there is no server. All the multiplayer code is contained in this repository and Worldcore's, yet you won't find networking or server code in either.
This is the Web version of Guardians, there is also a Unity port.
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install dependencies
npm i -
edit apiKey.js with your API key from croquet.io/keys.
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run it
npm start
The game is implemented using Worldcore.
- game.js: imports actors, pawns, and api key, starts session
- src/Actors.js: the shared simulation – bots, tanks, etc.
- src/Pawns.js: 3D models and UI
- src/Pawns-Avatar.js: tank controls
- src/Pawns-HUD.js: HUD widgets
The Lobby is implemented using plain Croquet (not Worldcore).
The lobby is a separate Croquet session. It shows a list of ongoing games. When entering a game, it is loaded in an iframe inside the lobby.
The game will periodically send "croquet-lobby" window messages to its parent iframe, which the LobbyView will use to publish "in-app-session" events to its shared Lobby model. That game-session will be added to the Lobby's sessions Map by its name so other lobby users can see and join it. After a timeout the session will be removed from the map, unless another "in-app-session" event was received.
For a given game session, only one of its user will be "elected" to relay messages to the lobby (see LobbyRelayActor in src/Actors.js and LobbyRelayPawn in src/Pawns.js). All other users will leave the lobby session, and if one of them is elected, only that user will rejoin the lobby session. This ensures scaling for the lobby.
Please ask questions on our discord.