Persistent and shared state

Ask Ziva: "Add multiplayer to my simple board game. Save the board and whose turn it is, so players can leave and return later."

The relay stores the room's saved game data, so it can survive everyone disconnecting, including the first player. There is no player host to lose. It can keep one saved-world snapshot and shared values such as the current turn. Your game must choose what to save and rebuild from it; a running scene is not saved automatically.

This suits turn-based, card, board and small persistent-world games. It is not Godot scene replication and is not meant to be combined with MultiplayerSpawner/MultiplayerSynchronizer networking. For real-time movement in a temporary co-op session, see Multiplayer. Compare both in Multiplayer limitations.

Before you use itCopy Anchor Link

• Access and bandwidth: the relay is included on Pro and Ultra. Bandwidth counts toward your account's monthly limit: a warning email arrives at 50 GB, and past 500 GB new connections are refused until the next calendar month (UTC). Players already connected stay connected.
• Limits: at most 32 connections per room and about 4 MB of saved room data with the connection code Ziva writes. Keep saves small, not full of artwork.
• Competing changes: any connected player can read and write room data. If two write the same value, the last write accepted by the relay wins.
• Privacy: shared data is sent to the hosted relay, stored there, and sent to players joining the room. Do not include secrets or private account information.