# How to Implement Real-Time Multiplayer in Godot
Real-time multiplayer functionality can take your Godot game to the next level, allowing players to compete or cooperate in the same world. However, implementing multiplayer networking requires careful planning and execution.
In this guide, we’ll cover:
– **Godot’s built-in networking tools**
– **Setting up a basic multiplayer game**
– **Synchronizing player actions**
– **Handling latency and prediction**
– **Best practices for multiplayer optimization**
—
## **1. Understanding Godot’s Networking System**
Godot provides a high-level networking API through the `ENetMultiplayerPeer` and `WebSocketMultiplayerPeer` classes, which handle peer-to-peer (P2P) and client-server communication.
### **Key Concepts:**
– **Peer:** A connected player or server.
– **RPC (Remote Procedure Call):** A function executed on another peer.
– **Network Authority:** Determines which peer controls an object.
– **Replication:** Synchronizing game state across clients.
Godot supports:
– **Authoritative Server Model** (recommended for competitive games)
– **Peer-to-Peer Model** (good for small, cooperative games)
—
## **2. Setting Up a Basic Multiplayer Game**
### **Step 1: Create a New Project**
Start a new Godot project and set up a simple 2D or 3D scene with a player character.
### **Step 2: Configure Network Settings**
Add a `MultiplayerAPI` node or configure networking in code:
“`gdscript
extends Node
var peer = ENetMultiplayerPeer.new()
func _ready():
# Host a server (default port: 8910)
if “–server” in OS.get_cmdline_args():
peer.create_server(8910)
multiplayer.multiplayer_peer = peer
print(“Server started on port 8910”)
# Connect as a client
else:
peer.create_client(“localhost”, 8910)
multiplayer.multiplayer_peer = peer
print(“Connecting to server…”)
“`
### **Step 3: Spawn Players Across Clients**
Use `@rpc` annotations to synchronize player spawning:
“`gdscript
@rpc(“any_peer”, “call_local”)
func spawn_player(id):
var player = preload(“res://player.tscn”).instantiate()
player.name = str(id) # Unique name for each player
add_child(player)
“`
Call this function when a player joins:
“`gdscript
func _on_peer_connected(id):
spawn_player.rpc(id)
“`
—
## **3. Synchronizing Player Actions**
To keep players in sync, use **RPCs** for movement and actions:
### **Sending Input Over the Network**
“`gdscript
func _physics_process(delta):
if multiplayer.is_server() or is_multiplayer_authority():
var input = Input.get_vector(“move_left”, “move_right”, “move_up”, “move_down”)
move_player.rpc(input)
@rpc(“any_peer”, “call_local”, “reliable”)
func move_player(input):
position += input * speed * delta
“`
### **Handling Ownership**
Set the **multiplayer authority** (who controls an object):
“`gdscript
func _ready():
if multiplayer.is_server():
set_multiplayer_authority(1) # Server controls NPCs
else:
set_multiplayer_authority(multiplayer.get_unique_id()) # Player controls themselves
“`
—
## **4. Dealing with Latency and Prediction**
### **Client-Side Prediction**
To reduce lag, clients predict their movement before the server confirms it:
“`gdscript
var pending_inputs = []
func _physics_process(delta):
var input = Input.get_vector(“move_left”, “move_right”, “move_up”, “move_down”)
move_player(input) # Local prediction
pending_inputs.append({“input”: input, “time”: Time.get_ticks_msec()})
send_input.rpc(input) # Send to server
@rpc(“any_peer”, “call_remote”, “unreliable”)
func send_input(input):
if multiplayer.is_server():
move_player.rpc(input) # Server validates and broadcasts
“`
### **Server Reconciliation**
The server corrects incorrect predictions:
“`gdscript
@rpc(“authority”, “call_remote”, “reliable”)
func correct_position(correct_pos):
position = correct_pos
# Replay pending inputs after correction
for input in pending_inputs:
move_player(input[“input”])
“`
—
## **5. Best Practices for Multiplayer Optimization**
1. **Use `unreliable` RPCs for frequent updates** (e.g., movement).
2. **Use `reliable` RPCs for critical actions** (e.g., shooting, scoring).
3. **Limit bandwidth** by sending only necessary data.
4. **Interpolate movements** to smooth out network delays.
5. **Test with high ping** to ensure robustness.
—
## **Conclusion**
Implementing real-time multiplayer in Godot requires:
– Setting up a server/client architecture
– Using RPCs for synchronization
– Handling latency with prediction and reconciliation
– Optimizing network traffic
With these techniques, you can create smooth, responsive multiplayer experiences.
**Next Steps:**
– Experiment with **lag compensation** (e.g., backward reconciliation).
– Try **WebSocket multiplayer** for browser-based games.
– Explore **Godot’s High-Level Multiplayer API** for simplified networking.
Happy networking! 🚀