Fallout Co-op 1.5.9

Two-player co-op for Fallout 1. Player 1 hosts; player 2 joins with their own character.

Built with AI: the code was written by an AI coding assistant (Claude) and directed and play-tested by a person; see How it was made.

You need your own copy of Fallout (GOG or Steam). No game files are included.

Install

Unpack into a folder of its own (not into the Fallout folder) and run fallout-ce.exe (Windows) or ./fallout-ce (Linux, needs SDL2: libsdl2-2.0-0).

The first start shows a setup screen that finds your Fallout installation and reads the game from there. Then pick MULTIPLAYER in the main menu. See COOP.md for how to play.

About these packages

Built by GitHub Actions from this release's source, with no server built in: you can play on a LAN, on one PC, or online by entering the host's address (the host forwards a port). The online server list, the relay for play without port forwarding, in-game updates and bug reports need a co-op server; see docs/coop/SERVER.md.

Both players need the same mod version and the same Fallout version and language.

Fixed in 1.5.9

• A rare crash while a map loads (moving the mouse cursor during loading could damage the game's memory).
• A rare crash in combat messages (the combat log read a door as if it were a person).