The seamless co-op mod for Dark Souls II: Scholar of the First Sin will be released on September 22, supporting up to six players completing the game together. Developed by modder Yui, it took approximately a year and a half to complete.
Yui has previously created seamless co-op mods for Elden Ring, Dark Souls, Dark Souls III, Elden Ring: Nightreign, and Armored Core VI: Fires of Rubicon, and is now adding Dark Souls II to the lineup. Development began in April 2025.
Once the mod is installed, players can cooperate with companions from the start of the game all the way to the final boss fight. The mod synchronizes NPC dialogue and removes area restrictions; character death does not end the current session, and all team members can participate in major boss battles.
Progress made during co-op sessions syncs to each player's own game. When the party defeats enemies, the results are retained in their individual worlds, and any obtainable items acquired during online play are transferred as well. The mod also adds proximity voice chat for PvP.
Addressing concerns that multiplayer might lower the difficulty, Yui stated that the mod adjusts balance based on party size and allows players to customize related settings. More experienced players can also enable an optional high-punishment mechanic to further increase the challenge.
The mod only supports the 64-bit version of Dark Souls II: Scholar of the First Sin and cannot be used with the 32-bit original Dark Souls II. It will be available for download via Nexus Mods after release.