How to build a multiplayer game with unity

build multiplayer game with unity
April 11, 2025
5 min read
By Cojocaru David & ChatGPT

Table of Contents

This is a list of all the sections in this post. Click on any of them to jump to that section.

index

Building a Multiplayer Game in Unity: A Comprehensive Guide

Creating a multiplayer game in Unity unlocks a world of engaging player experiences. From fast-paced shooters to collaborative adventures, Unity’s robust tools empower you to bring your multiplayer vision to life. This guide provides a clear, step-by-step walkthrough of the essential aspects of multiplayer game development, covering networking setup to performance optimization.

Why Unity Stands Out for Multiplayer Development

Unity has become a leading engine for multiplayer games, celebrated for its flexibility, powerful networking capabilities, and a vibrant, supportive community. It accommodates diverse networking approaches, including Unity’s own Netcode for GameObjects (NGO) and popular third-party solutions like Photon.

Here’s what makes Unity ideal for multiplayer projects:

  • Cross-Platform Compatibility: Seamlessly deploy your game across PC, consoles, and mobile devices, expanding your reach.
  • Integrated Networking Tools: Simplify complex tasks like data synchronization and player management with Unity’s built-in features.
  • Scalable Architecture: Design your game to handle a wide range of player counts, from small groups to massive online communities.
  • Asset Store Ecosystem: Access a vast library of pre-built assets and tools to accelerate your development process.

Project Setup: Laying the Foundation

Before you begin implementing multiplayer features, setting up your Unity project correctly is crucial:

  1. Install Unity Hub and an LTS Version: Download Unity Hub and select the latest Long-Term Support (LTS) version for optimal stability and reliability.
  2. Create a New Project: Choose a 3D or 2D project template based on your game’s design.
  3. Import Essential Packages: Utilize the Package Manager to import necessary packages, such as Netcode for GameObjects (NGO), which streamlines networking functionalities.

Maintain a well-organized project structure with dedicated folders for scripts, assets, and scenes. Consistent organization will greatly improve your workflow.

Implementing Multiplayer Networking with Netcode for GameObjects

Unity offers several networking solutions; here’s how to get started with Unity Netcode:

1. Install Netcode for GameObjects (NGO)

Open the Package Manager (Window > Package Manager) and search for “Netcode for GameObjects”. Install the package. This package provides the fundamental components you need to manage players, objects, and Remote Procedure Calls (RPCs).

2. Configure the NetworkManager

Create an empty GameObject in your scene and add the NetworkManager component to it. The NetworkManager is responsible for managing connections, spawning players, and handling overall network synchronization. Configure its settings, such as the transport protocol (e.g., UDP).

3. Create and Configure Player Prefabs

Design your player character as a prefab. Add a NetworkObject component to the player prefab to enable network synchronization. Write scripts for player movement and input, inheriting from NetworkBehaviour instead of MonoBehaviour. This is crucial for network-aware behavior.

4. Synchronize Game State and Implement RPCs

Use NetworkVariable<T> to automatically synchronize data like player health, score, or position across the network. For real-time actions and events, use Remote Procedure Calls (RPCs):

[ServerRpc]
public void ShootServerRpc()
{
    // Server-side logic to handle shooting, such as reducing ammo or damaging targets.
}
 
[ClientRpc]
public void PlaySoundClientRpc()
{
  //Client-side logic to play the shooting sound.
}

Testing and Debugging Your Multiplayer Game

Thorough testing is vital for a successful multiplayer game. You’ll need to simulate multiple clients to identify and fix issues:

  • Utilize ParrelSync: Employ ParrelSync to create cloned instances of your Unity project for local testing, simulating multiple players on a single machine.
  • Host and Join Sessions: Actively host and join game sessions to verify connectivity, player synchronization, and overall game flow.
  • Monitor Network Traffic: Use Unity’s Profiler (Window > Profiler) to analyze network traffic, identify bottlenecks, and optimize data transmission.

Address common issues like lag, desynchronization, and incorrect authority handling early in the development process. Frequent testing is essential.

Optimizing Multiplayer Performance for Smooth Gameplay

Optimizing performance is key to ensuring a smooth and enjoyable multiplayer experience for all players:

  • Reduce Bandwidth Usage: Compress network data and only synchronize essential information to minimize bandwidth consumption.
  • Implement Client-Side Prediction: Employ client-side prediction techniques to compensate for latency and create a more responsive feel.
  • Employ Object Pooling: Utilize object pooling for frequently spawned objects like projectiles or particle effects to reduce garbage collection and improve performance.
  • Optimize Scene Complexity: Reduce the complexity of your scenes by minimizing the number of objects and using efficient rendering techniques.

Publishing Your Multiplayer Game: Reaching Your Audience

Once your game is polished and thoroughly tested, prepare it for launch:

  1. Choose a Hosting Solution: Select a suitable hosting solution based on your game’s requirements, such as Unity Relay, a dedicated server provider, or a cloud-based solution.
  2. Conduct Beta Testing: Release a beta version to a small group of players to gather feedback, identify remaining issues, and fine-tune the gameplay.
  3. Deploy on Platforms: Distribute your game on platforms such as Steam, itch.io, or mobile app stores to reach your target audience.

Conclusion: Embrace the Challenge

Developing a multiplayer game with Unity is a rewarding endeavor that requires dedication and creativity. By mastering Unity’s networking tools, optimizing performance, and rigorously testing, you can create a compelling and engaging multiplayer experience that captivates players worldwide.

“The heart of a great multiplayer game lies in the shared experiences it creates. Focus on fostering meaningful connections and memorable moments for your players.”