RPCs - Example Uses

RPCs are how you trigger ephemeral events across clients. The patterns below are the ones you will reach for most often. This page assumes familiarity with RPC Basics.

Client → Server Requests

Clients do not own game state - the simulation server does. So when a client wants something to happen, it packages intent as a broadcast RPC and lets the master client (the server) validate and act on it.

Typical requests:

Spawn a character with a chosen payload - loadout, class, cosmetics. The master receives the request, validates it and spawns on behalf of the requester.
Loot a nearby pickable - the client that walked into range sends a loot request; the server checks proximity and availability, then applies the effect.

The full spawn-request pattern with working code is already documented in the Quick Start Guide (Step 5) - use that as your template.

Server → All Clients Notifications

RPCs are not cached. A player who joins after the call will not see it. That makes RPCs a good fit for short-lived notifications that late joiners do not need to know about:

A hit flash or kill-feed entry
A round-start siren or countdown tick
A one-shot VFX burst triggered by a server-side event

Anything that needs to survive late joins belongs in a replicated property instead - a late joiner will receive the latest value on spawn. Use RPCs only for the ephemeral half.

Common Patterns

Text Chat

Chat is a textbook fit for broadcast RPCs: one client sends, everyone receives, nothing needs to survive late joins.

GDScript

func _ready():
    Fusion.register_broadcast_receiver(self)

func _exit_tree():
    if Fusion:
        Fusion.unregister_broadcast_receiver(self)

@rpc("any_peer", "call_local")
func chat_message(sender: String, text: String):
    $ChatPanel.append_line("[%s]: %s" % [sender, text])

func send_chat(text: String):
    Fusion.rpc(chat_message, local_player_name, text)

For production-grade chat, consider Photon Chat - a separate Photon product with turnkey features like AI moderation and word filtering via compatible third-party integrations, out of scope for raw RPCs.

UI and One-Shot Effects