iDos Games
Create
Multiplayer

How to make a multiplayer game without a server

How to make a multiplayer game without a server of your own: WebRTC rooms, invites, voice chat and a host who starts the game, built with AI in the browser.

5 min readUpdated: РусскийҚазақша中文한국어日本語हिन्दीPortuguêsDeutsch

To make a multiplayer game without a server of your own, build the game on iDos Games and ask the AI coder to make it multiplayer. The platform adds ready rooms to the lobby: friends join by invite or from the public list, talk in voice chat, and the host presses Play to start the game on every device. Players then connect directly over WebRTC, so there is no game server for you to rent, run or update.

Most AI game makers write the game itself well and stop at online play. A generated project has no matchmaking, no signaling and no relay for hard networks, so it stays single-player. This guide explains what "without a server" really means and how to get a working online game in an afternoon.

What "without a server" really means

No browser game is completely serverless. Two browsers cannot find each other on their own: something has to tell each one the other's address before they can talk directly. What you can avoid is the expensive part, a game server that runs the match for every player.

PieceWhat it doesWho runs it here
Lobby and roomsplayers find each other, invites, ready checkiDos Games
Signalingswaps connection details so browsers can connectiDos Games
STUNtells each player their public addressstandard, free
TURN relaycarries traffic when a direct link is blockedset up in the dashboard
The match itselfgame state, moves, physicsplayers' browsers, the host leads

So "without a server" means without your server. The game runs in the players' browsers, one of them acts as the host, and the platform only does the matchmaking and the handshake.

Host or mesh: how the game stays in sync

There are two common ways to keep players in sync:

  • Host: one player's browser owns the game state, the others send their inputs and receive updates. Simple and fair enough for co-op and casual competitive games. This is what iDos Games rooms use.
  • Mesh: every player sends updates to every other player. No single owner, but traffic grows fast with each extra player.

For a first online game, host is the right choice. Write your game so the host decides what happened (who picked up the coin, who got hit), and the other players only show it.

What players get

  • Rooms in the lobby: public, or private with an invite code, for 2, 4 or 8 players.
  • Ready check and room chat, with host and offline marks on every member.
  • Voice chat: push-to-talk on V or open mic, mute and volume per member, and a mark on whoever is speaking.
  • The host's Play takes the whole room into the game at once.
Multiplayer
12 450
320
Mira's room3/4 · public
Join
Friends only2/8 · by invite
Code
My room · 3/4

You (host) · Mira ✓ · Arrow ✓ · waiting…

Voice
Play
Create a room
Rooms of the games that play online: public or private by invite.
Members with "Ready", room chat and voice chat.
The host's "Play" takes the whole room into the game.
Example. The multiplayer lobby: rooms, members, voice and "Play" for the whole room.

Step 01Create the game

Open Create and describe the game, for example: "a co-op voxel survival game where friends build a base together". Answer the short questions about genre and style, and the platform picks a starting template. The voxel sandbox plays online from the start, so it is the fastest way to see multiplayer working.

Games that work well online on the first try: co-op building, party quiz, card duels, racing against ghosts, simple arena shooters. Games that are harder: anything with fast physics between players, where small delays matter.

Step 02Ask for multiplayer

In the AI coder write one request:

Make the game multiplayer for 4 players.

The AI coder installs the multiplayer system and registers the game in the lobby. After that, "With friends" appears next to the game's Play button. Then describe what each player does:

Each player controls their own knight. The host spawns the monsters and decides who hit what. Show the other players' names above their heads.

Step 03Turn it on in the dashboard

Open the dashboard, pick your project and go to Live Operations → v2 → Multiplayer. Turn multiplayer on and set the maximum players per room. On the same page you set up the relay (TURN) server for players behind strict networks, such as some mobile carriers and office Wi-Fi.

Step 04Test with a friend

Open the test version on two devices, ideally on different networks: one on Wi-Fi, one on mobile data. Create a room on one, join it from the other with the invite code, check the voice chat, press Play as the host and watch both devices enter the game.

What to check:

  • Do both players see each other move smoothly?
  • What happens when the host closes the tab?
  • Can a third player join a running game, if you allowed it?

Add chat if you want players to talk outside rooms too.

Step 05Publish and invite

Deploy the checked version. The game gets its own address, so you can send the link to friends right away, and list it in the idosgames.com catalog when you are ready. Friends sign in with one iDos Games account, and the same account works in every game on the platform.

Common problems and fixes

  • Players see each other jump or teleport. Ask the AI coder to smooth the other players' movement between updates instead of snapping to each new position.
  • Two players pick up the same coin. Only the host should decide pickups and hits; the others ask the host.
  • One friend can never connect. Their network blocks direct links. Check that the relay (TURN) server is set in the dashboard.
  • The game breaks when the host leaves. Decide what happens: end the match for everyone, or let late joiners and the remaining players continue where the game allows it.

For developers

Rooms work through client.multiplayer and RealtimeSession from @idosgames/core/realtime. A game module registers itself in the lobby with ctx.multiplayer.registerGame, choosing the topology, the room chat and the maximum players. Every field is described in the multiplayer-realtime skill of the SDK MCP server, so an agent such as Claude Code can wire it up for you.

Aidos Ryskeldinov

About the author

Founder of iDos Games

Lifelong gamer and tech enthusiast. Since 2020 I have been building and shipping cross-platform games and apps, and today I'm building iDos Games: a platform where anyone can make a game with AI, put it live at its own link and earn from it. Here I share how to make games faster and easier than you'd think.

Frequently asked questions

Do I need to rent a game server?

No. Players connect to each other over WebRTC, and iDos Games runs the rooms and the connection setup. You do not run or pay for a game server of your own.

How many players can play together?

A room holds 2, 4 or 8 players. You set the maximum for your game in the dashboard.

Can friends talk during the game?

Yes. Rooms have a text chat and a voice chat with push-to-talk, an open mic option, and mute and volume for every member.

What happens if a player is behind a strict network?

Some networks block direct connections between players. For them the connection goes through a relay (TURN) server, which you set up on the Multiplayer page of the dashboard.

Can someone join a game that already started?

Yes, if your game allows it. The voxel sandbox template lets late joiners enter a running world, and any game can switch this on when it registers in the lobby.

Learn more in the documentation

Make your own game

Describe the idea in a sentence - the AI coder builds it, and it goes live at its own link.

CreateConnect an AI agent

All articles