How to Fix a Godot RPC Failing With an Authority Mismatch

Godot 4 RPC routing depends on each node's multiplayer authority being consistent across peers. If a client calls an authority-only RPC, or authority differs between machines, the call is silently rejected.

How to fix it

1. Set authority identically on all peers

Assign set_multiplayer_authority(id) at the same point in spawn logic on every peer (commonly the spawner does this) so the node agrees on who owns it everywhere.

2. Match the rpc annotation to the caller

Use @rpc("any_peer") for client-to-server calls and @rpc("authority") for server-to-client. A client calling an authority RPC is dropped; flip the annotation or route through the server.

3. Add call_local when the caller must run it too

If the sending peer should also execute the function, include call_local in the annotation, otherwise the RPC runs only on the remote side.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Godot error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.