Your device
Your device runs the game. All maps, models, textures and sounds are loaded from your own copy of MW2 (2009), downloaded from Steam to your device or read from your own Steam install on PC. They stay on your device.
MULTIPLAYER
How multiplayer works
IW4L Mobile multiplayer is built so that game files never leave your device. Not to us, not to other players, not to any server. This page explains exactly what happens when you play online, for players and for anyone who wants to check our work.
THE SHORT VERSION
The short version
- One player hosts the match on their own device.
- Other players connect to the host through one of our relay servers.
- The relay only forwards encrypted game traffic, like movement and shots. It never sees, stores or sends any game files.
- Every player loads the maps, models and sounds from their own licensed copy of MW2 (2009).
THE THREE PARTS
The three parts
The host
One player in each match is the host. Their device runs the match: it keeps track of the score, who's where, and who hit whom. The host has no special access to anyone's game files, and nobody has access to theirs.
The relay servers
Most home networks and mobile networks block direct connections between players. The relay servers solve that by passing messages between the players and the host. Think of them like a mail carrier that delivers sealed envelopes: they move the envelopes, but can't open them.
PlayerGame files stay here
Relay serverForwards encrypted messages only. No game files.
Host playerGame files stay here
ON THE NETWORK
What travels over the network, and what never does
Sent during a match
- Your movement and where you're aiming
- Shots, hits and weapon switches
- Score and match events
- Which map is being played, by name only (for example "Rust")
- Your in-game player name
Never sent
- Maps, models, textures or sounds
- Game code, scripts or any other game files
- Your Steam login or password
- Anything from your device besides the match itself
When a match starts on Rust, nobody sends anybody the map. Each player's device already has it from their own copy, and only the name "Rust" goes over the network.
VISIBILITY
What the relay can and can't see
Because the traffic is encrypted end to end, the relay can't read what's inside it. Like any server on the internet, it does see:
- The IP addresses of connected players, so it knows where to deliver messages
- How much data is passing through, and when
- The match listings: map name, player count and region
VERIFICATION
For rights holders and technical reviewers
We want this to be easy to verify, not just something you have to take our word for.
- Contact: iw4mobile@gmail.com. We respond promptly to any request from Activision, its licensors, or Valve.
IW4L Mobile is an independent, free and non-commercial fan project. It is not affiliated with, endorsed, sponsored or approved by Activision, Infinity Ward or Valve. Call of Duty® and Modern Warfare® 2 are trademarks of Activision Publishing, Inc.
FAQ
Multiplayer questions.
FOLLOW DEVELOPMENT
Follow development
Testing, bug reports and games happen in the Discord.
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