Remote procedure calls in Unity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Remote Procedure Call (RPC) in Unity?

An RPC in Unity is a way to call a function on another computer or player over the network, making multiplayer games work smoothly.

beginner

How do you mark a method as an RPC in Unity's networking system?

You mark a method with the [PunRPC] attribute when using Photon, or use [ClientRpc] in Unity's Netcode for GameObjects to indicate it can be called remotely.

intermediate

What is the difference between a ClientRpc and a Command in Unity networking?

A Command is called by a client to run code on the server, while a ClientRpc is called by the server to run code on clients.

intermediate

Why should RPCs be used carefully in multiplayer games?

Because RPCs send data over the network, using too many or large RPCs can cause lag or slow down the game experience.

beginner

Give an example of a simple RPC method in Unity using Photon.

Example:<br>

[PunRPC]
void Jump() {
  // Make the player jump
}

What does an RPC do in Unity multiplayer games?

A Calls a function on another player or server over the network

B Saves game data locally

C Draws graphics on the screen

D Handles user input only

RPCs let you run code on other players' computers or the server, enabling multiplayer interaction.

Which attribute is used to mark a method as an RPC in Photon Unity Networking?

A [ClientRpc]

B [PunRPC]

C [Command]

D [Remote]

Photon uses [PunRPC] to mark methods that can be called remotely.

In Unity's Netcode for GameObjects, what does a ClientRpc do?

A Runs code on clients from the server

B Runs code on the server from clients

C Saves player preferences

D Handles physics calculations

ClientRpc methods are called by the server to execute code on all or specific clients.

Why should you limit the number of RPC calls in your game?

A RPCs slow down graphics rendering

B RPCs use too much memory locally

C Too many RPCs can cause network lag

D RPCs are not supported on mobile devices

Excessive RPC calls increase network traffic and can cause lag.

Which of these is NOT a typical use of RPCs in Unity multiplayer?

A Synchronizing player actions

B Triggering animations on other players

C Updating game state across players

D Loading local game assets

Loading local assets is done locally, not via RPCs.

Explain how Remote Procedure Calls help multiplayer games in Unity work.

Think about how players see each other's actions in real time.

Describe the difference between ClientRpc and Command in Unity networking.

Who calls whom in each case?