Multiplayer Netcode Fundamentals for Indie Developers: A Complete Guide

Steven Marrone·January 26, 2026·0 comments

Making Your Game Multiplayer Without Losing Your Mind

After shipping three multiplayer games (two that flopped, one that didn’t), here’s what I wish someone had told me about netcode from the start. Multiplayer netcode is the code responsible for synchronizing game state between players over the internet—and it’s where most indie multiplayer projects die.

This guide covers the fundamental concepts of multiplayer netcode for indie game development: which architecture to choose, how to handle the inevitable lag, and which tools will save you months of headaches. We’re focusing on small-scale co-op and competitive games—think Among Us, Lethal Company, or PEAK—not MMOs.

Table of Contents

Quick Answer: What You Need to Know

  • Client-Server architecture is almost always the right choice for indie games—it’s more secure and easier to reason about
  • Tick rate (how often your server updates) should be 20-60Hz for most games; higher isn’t always better
  • Prediction and reconciliation make movement feel responsive despite latency
  • Use existing solutions like Unity Netcode for GameObjects, Mirror, or Photon—don’t build from scratch
  • Test with artificial lag from day one—what feels smooth on LAN will be chaos at 150ms

Client-Server vs Peer-to-Peer: Which One?

The first decision in multiplayer netcode is your network architecture. You have two main options, and this choice will affect everything that follows.

Client-Server Architecture

How it works: One machine (the server) is the authoritative “source of truth.” All players (clients) send their inputs to the server, and the server sends back the game state.

Pros:

  • Much harder to cheat—the server validates everything
  • Consistent game state for all players
  • Easier to debug (one source of truth)
  • Works well for competitive games

Cons:

  • Requires server hosting (or one player acts as host)
  • Single point of failure
  • Slightly more latency for non-host players

Peer-to-Peer Architecture

How it works: All players are equal, sharing data directly with each other. No central server.

Pros:

  • No server costs
  • Lower latency between nearby players
  • Simpler initial setup

Cons:

  • Easier to cheat (no authority)
  • Connection quality varies wildly
  • Harder to sync complex game states

The verdict: For most indie games, use client-server with a player-hosted model (one player is the “host”). Games like Among Us, Lethal Company, and PEAK all use this approach. It gives you security and simplicity without dedicated server costs.

Core Netcode Concepts You Must Understand

Tick Rate

Your tick rate is how many times per second your server updates the game state. A 60Hz tick rate means 60 updates per second.

Guidelines:
Casual co-op games: 20-30Hz is fine
Action games: 30-60Hz
Competitive shooters: 60-128Hz

Higher tick rates mean more responsive gameplay but significantly more bandwidth. For most indie games, 30Hz strikes the right balance.

State Synchronization

You need to decide what data to sync and how often. The golden rule: send only what’s necessary.

Essential data: Player positions, critical game events, inputs
Can be interpolated: Rotations, velocities, animations
Send rarely: Inventory updates, stats, cosmetics

Delta Compression

Instead of sending full state every tick, send only what changed since the last update. This dramatically reduces bandwidth. Most networking libraries handle this automatically, but understanding the concept helps you design bandwidth-efficient games.

Handling Lag Like a Pro

Every player has latency—the time it takes for data to travel between client and server. Your job is to make the game feel responsive despite this unavoidable delay.

Client-Side Prediction

The client “predicts” the result of player actions immediately, without waiting for server confirmation. When you press forward, your character moves instantly on your screen—the client assumes the server will agree.

This is why your own character feels responsive while other players might stutter. You’re seeing your predicted movement, not waiting for the round-trip to the server.

Server Reconciliation

Sometimes your prediction is wrong—maybe another player pushed you, or the server rejected your movement. Reconciliation corrects your client’s state to match the server’s authoritative version.

Good reconciliation is invisible. Bad reconciliation causes “rubber-banding” where players snap back to previous positions.

Interpolation

For other players’ movements, you can’t predict what they’ll do. Instead, you interpolate between known positions to smooth out their movement. The tradeoff: other players appear slightly in the past (typically 50-100ms behind reality).

Lag Compensation for Hits

Here’s a common scenario: you shoot at an enemy, but by the time your shot reaches the server, they’ve moved. Do you hit or miss?

Lag compensation “rewinds” the server state to when you fired, checking if the shot would have hit at that moment. This makes shooting feel fair even with latency. Games like Valorant and Call of Duty use sophisticated versions of this technique.

Best Tools for Indie Multiplayer Development

Don’t build netcode from scratch. Here are the proven solutions:

Unity Developers

Netcode for GameObjects (NGO) — Unity’s official solution. Best for co-op games with 2-8 players. Free, well-documented, actively maintained. This is what we recommend for most Unity indies.

Photon (PUN/Fusion) — Mature ecosystem with relay servers included. Great if you want to avoid NAT traversal headaches. Free tier for small games, scales with usage.

Mirror — Open-source community fork of the old UNet. Very stable, lots of examples. Good choice if you want more control or are building something unusual.

Godot Developers

High-Level Multiplayer API — Built into Godot 4. Uses ENet under the hood. Good for getting started quickly.

Nakama — Open-source backend that works with any engine. Overkill for simple co-op but great if you need accounts, matchmaking, and leaderboards.

Unreal Developers

Built-in Replication System — Unreal’s native solution is battle-tested in countless AAA games. Steep learning curve but incredibly powerful.

Mistakes That Kill Multiplayer Projects

1. Not testing with latency from day one
What works on localhost will fail spectacularly at 200ms. Use tools like clumsy (Windows) or Network Link Conditioner (Mac) to simulate real-world conditions.

2. Syncing too much data
Every byte costs bandwidth. Players don’t need to know about objects they can’t see. Implement interest management—only sync what’s relevant to each client.

3. Trusting client input
Never trust the client. Validate everything server-side. If the client says “I dealt 999 damage,” verify that’s actually possible.

4. Ignoring packet loss
The internet drops packets. Your game needs to handle missing updates gracefully. Use UDP with your own reliability layer for important messages, or use a library that handles this.

5. Building netcode last
Retrofitting multiplayer onto a single-player codebase is painful. If you know you want multiplayer, architect for it from the start.

Pro Tips

  • Start with host-client, not dedicated servers. Let one player host. You can add dedicated server support later if needed.
  • Implement a “network debugger” UI early. Show ping, packet loss, and tick rate during development. You’ll thank yourself later.
  • Use deterministic physics sparingly. It’s tempting for perfect sync, but the complexity cost is usually not worth it for small games.
  • Plan for players with bad connections. Kick them gracefully with a clear message rather than letting them ruin the experience for everyone.
  • Version your network protocol. When you update your game, old clients trying to connect to new servers (or vice versa) should get a clear “update required” message, not undefined behavior.
  • Log network events religiously. When things go wrong (and they will), logs are your only window into what happened across multiple machines.

Frequently Asked Questions

How much bandwidth does multiplayer require?

For a typical 4-player co-op game at 30Hz, expect 10-50 KB/s per player. Shooters with more state sync might hit 100+ KB/s. Most home connections handle this easily, but mobile data caps can be a concern.

Can I add multiplayer to my existing single-player game?

Technically yes, but it’s painful. Expect to refactor significant portions of your codebase. The earlier you decide on multiplayer, the easier the implementation.

Should I use TCP or UDP?

For real-time games, UDP with custom reliability for important packets. TCP’s guaranteed delivery creates head-of-line blocking that causes stuttering. Most networking libraries handle this choice for you.

How do I handle cheaters?

Server-authoritative architecture is your first defense. Validate all client inputs server-side. For competitive games, consider adding replay systems and report functionality. Anti-cheat software is usually overkill for small indie games.

What’s the minimum viable multiplayer implementation?

For a simple co-op game: position sync, basic lag compensation, host migration (optional). You can launch with just these fundamentals and improve the netcode based on player feedback.

Summary

Multiplayer netcode doesn’t have to be terrifying. Start with client-server architecture and a player-hosted model. Use proven tools like Unity NGO, Photon, or Mirror instead of building from scratch. Implement prediction and reconciliation for responsive controls, and always test with artificial latency.

The best multiplayer games feel smooth not because they eliminated lag—that’s physically impossible—but because they hide it intelligently. Master these fundamentals, and you’re well on your way to shipping a multiplayer game that actually feels good to play.

Steven

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