W3Coop 0.1.0 (pre-release)

First public build of Witcher Online for The Witcher 3 Remastered (patch 5.01), with a Steam relay so friends can join without opening ports.

Pre-release: it has been tested with two game copies on one PC, not yet between two real Steam accounts on different PCs. Please report what works and what doesn't in Issues.

What you get: players see each other in their own worlds and can travel together. Each player keeps their own save; enemies, quests and loot are not shared yet. Gwent duels between players are switched off.

Install: close the game, then copy the contents of the zip into your Witcher 3 folder (the one with bin and content). The host needs Java 21+. Steam must be running.
Play: the host runs bin\w3coop\Host co-op.cmd and invites friends. Friends run bin\w3coop\Join co-op.cmd. Then everyone starts the game and loads a save. W3Coop\README.txt has the details, troubleshooting and how to uninstall.

Doesn't work with Custom Player Characters or Chill Out installed. Unsubscribe from the Workshop mod "Fast travel from anywhere", which stops every mod from loading on Remastered.

Source: Emillock/WitcherOnline remastered-5.01 (GPL-3.0; also included in the zip under W3Coop\source) and this repo.

W3Coop-0.1.0.zip SHA-256: 40f5fe664dcd46a557d49591a9954b403d30868f2ef59be806bcf6c2f580f43e