FreeOrion supports Multiplayer games.
Hosting a game
To host a multiplayer game, choose "Multiplayer" and enter your player name. Player names should contain only letters, numbers an underscores (a-z, A-Z, 0-9, _) and no spaces.
After pressing "Okay", you will see a window "Multiplayer Setup", where you can configure the game parameters.
Please note that player names, empire names and colours must be choosen unique, or the button "Start Game" will not be active.
Joining a game
In the main menu choose "Multiplayer", enter your player name and choose a game out of the list. Or you can manually enter a host name or IP address at the bottom of this page.
The freeorion multiplayer part runs on TPC port 12346. You may need to forward this port in your router or firewall.
The discovery port uses UDP 12345 and is used to discover running games. You don't need to forward this port to run a game.