TpF2 Multiplayer
A large Transport Fever 2 map with towns, roads and industries
TFMP logo

Build one world,
together.

TpF2 Multiplayer adds real multiplayer to Transport Fever 2. Everyone in the session builds in the same world at the same time, and every road, station, vehicle and line appears for all players at once.

Download installer View source

Free and open source (MIT) · Windows, Steam version of the game · Experimental

What you can do

It is the game you already know, with friends in it. No separate client, no dedicated server to rent.

Build side by side

Lay track, draw roads, place stations and depots, buy vehicles and set up lines. Everyone sees the result the moment it happens.

Share a company, or compete

Run one company together with one bank balance, or give each player their own company and money on the same map.

Start from the title menu

Host a game and send the code, join a friend's, or pick one from the public list. A relay server helps when nobody can open a port.

How a click reaches everyone

Transport Fever 2 has no network code, so the mod keeps every copy of the world identical instead: the same commands, applied at the same moment of the simulation, on every computer.

A command travelling from player A to players B and C Player A builds a road. The game holds the command back and sends it to players B and C, who receive it shortly after. All three games apply it at the same simulation step. simulation time → Player A Player B Player C held back on A's own game too A builds a road received received the agreed step the road appears in all three worlds
Each action is stamped with a simulation step a moment in the future and sent to every player. Every game, the player's own included, applies it at exactly that step, so the worlds never drift apart. A checker keeps comparing them, and the in-game Multiplayer window shows whether they match.

Under the hood, a small DLL loads alongside the game, captures each command before it applies, and hands it to a game-script mod that replays it on schedule. A separate lobby program connects the players, encrypts their traffic and sends the save. The architecture notes go into detail.

Download and play

  1. Download TpF2Multiplayer.msi from the latest GitHub release. Everyone in a session needs the same version.
  2. Close the game and run the installer. It finds Transport Fever 2 through Steam and adds the multiplayer files and mod.
  3. Host or join. On the title menu, open Multiplayer. The host shares the code; friends paste it and join, then everyone loads the shared save.

This is an unofficial, experimental project. Sessions of up to four players have been played, on one PC and across the internet. Keep backups of your saves and read the known issues first.

Code signing policy

Releases are currently unsigned. Before running the installer, check its SHA-256 checksum against the one in the release notes.

The project intends to apply to the SignPath Foundation for free code signing of its Windows installer and DLLs. If the application is accepted, signed releases will carry the notice: Free code signing provided by SignPath.io, certificate by SignPath Foundation.

Signed files would be built only from this project's public source repository, by an automated build that is still being set up. Committer and approver: the project maintainer, silver2127, who would approve every signing request.

Everything the software sends over the network, to whom, and what is kept is listed in the privacy policy.