Days Gone gets an experimental co-op mod for up to four players

Days Gone Multiplayer lets you join up with one to three other players through Steam lobbies or direct-IP connections, with persistent multiplayer saves kept separate from your solo saves. Orgueilleux's October 26 release is an experimental early alpha: missions, combat, enemy AI, bikes, revivals, cutscenes and world interactions are only partly synchronized.

You'll need Steam's Days Gone 1.13 on 64-bit Windows and matching mod builds. There's no split-screen; other stores, Linux, Proton and Steam Deck remain unvalidated. Back up your saves and follow the creator's guidance for the bundled UE4SS before replacing loader files.