Building a Multiplayer Endless Runner Game in Unity

Introduction

Endless runner games have become a popular genre in the mobile and PC gaming industry. Their addictive mechanics and simple controls make them appealing to players of all ages. Adding multiplayer functionality to an endless runner takes the excitement to the next level by introducing real-time competition, leaderboards, and cooperative gameplay.

In this blog, we’ll walk through the process of building a multiplayer endless runner in Unity, from setting up core mechanics to integrating networking solutions for real-time gameplay.

Core Game Mechanics of an Endless Runner

Before adding multiplayer, it’s essential to set up the single-player foundation:

1. Character Controller
   • Implement movement logic for running, jumping, sliding, and dodging.
   • Use Unity’s CharacterController or Rigidbody for smooth physics.
2. Infinite Level Generation
   • Create repeating terrain or platform segments.
   • Use object pooling to recycle obstacles and environment elements.
3. Obstacles and Power-ups
   • Add dynamic hazards like walls, gaps, or enemies.
   • Introduce power-ups (e.g., shields, speed boosts, magnet coins) for variety.
4. Scoring System
   • Score based on distance traveled and coins collected.
   • Add multipliers for power-ups to increase engagement.

Adding Multiplayer to the Game

1. Choosing a Networking Solution

Unity offers several options for multiplayer:

• Photon PUN / Fusion – Popular for real-time multiplayer, with matchmaking and room creation.
• Unity Netcode for GameObjects (NGO) – Unity’s official networking solution.
• Mirror – Open-source and easy to integrate.

For real-time endless runners, Photon Fusion is a great choice due to low-latency synchronization.

2. Player Synchronization

• Ensure each player’s character movement is synced across all clients.
• Use network transform components for position, rotation, and animation synchronization.
• Optimize by sending only essential updates to reduce lag.

3. Multiplayer Matchmaking

• Allow players to create or join lobbies.
• Implement random matchmaking for quick play.
• Support private rooms with friend invites.

4. Handling Game State

• Decide on host authority vs. server authority:
  • Host authority works well for casual games.
  • Dedicated server authority prevents cheating and ensures fairness.
• Sync game state: distance traveled, obstacles generated, and leaderboards.

Designing Competitive Features

1. Real-time Leaderboard
   • Show all players’ scores during gameplay.
   • Update dynamically as players progress.
2. Elimination Mechanics
   • If a player hits an obstacle, they could be eliminated while others continue.
   • Alternatively, use “lives” or revival tokens.
3. Spectator Mode
   • Allow eliminated players to watch remaining players until the game ends.
4. Rewards & Progression
   • Add achievements, skins, and coins for long-term engagement.

Optimizing for Performance

• Object Pooling: Reuse platforms and obstacles to reduce memory allocation.
• Lag Compensation: Use client-side prediction to smooth out delays.
• Mobile Optimization: Reduce draw calls, use baked lighting, and compress textures.
• Scalable Networking: Ensure smooth gameplay even with higher player counts.

Testing and Deployment

1. Local Testing
   • Test with multiple instances in the Unity Editor.
   • Simulate network latency and packet loss.
2. Cloud Deployment
   • Use Photon Cloud, PlayFab, or Unity Game Server Hosting for matchmaking and sessions.
3. Cross-Platform Support
   • Export to Android, iOS, and PC for broader reach.

Conclusion

Building a multiplayer endless runner in Unity requires balancing fun mechanics with smooth real-time networking. By focusing on synchronization, matchmaking, and competitive features like leaderboards, you can deliver an engaging experience that keeps players hooked.

With Unity’s tools and modern networking solutions like Photon Fusion, developers can bring multiplayer endless runners to life—combining fast-paced action with the thrill of competing against real players worldwide.