Seamless Co-op for Dark Souls II is out – you can play through the campaign with a party of up to six

Modder Yui has released Seamless Co-op for Dark Souls II: Scholar of the First Sin, which lets players get through almost the entire game with friends without most of the restrictions of FromSoftware’s standard multiplayer. A single session can hold up to six people – the host and five more players.

The mod came out on September 22 and is still in an alpha state. As of publication, the current version is 0.0.3, which already fixes performance issues on some CPUs and the awarding of Steam achievements to guest players.

You can download the mod from the Seamless Co-op page on Nexus Mods.

The session doesn’t end after a boss or a death

The main goal of Seamless Co-op is to turn Dark Souls II’s co-op into a full-fledged playthrough together.

In the original multiplayer system, allies regularly return to their own world after killing a boss or meeting other conditions. Here there are virtually no such restrictions.

The session persists after:

• defeating bosses;
• player deaths;
• resting at a bonfire;
• moving between areas;
• passing through fog gates.

If a regular player dies, they respawn at the last bonfire they used and stay in the same co-op game. Boss fights work a little differently: a fallen participant temporarily becomes a spectator until the fight ends or the group rests at a bonfire.

NPC dialogue and world events are synced between players, and story progress made in a co-op session carries over into each participant’s own world.

Up to six players and distance-based voice chat

Yui also reworked Dark Souls II’s networking substantially. The mod uses a more modern Steam networking API, and to connect you just need to install the same version of the mod and set a shared session password.

The maximum party size is six people.

A proximity voice chat is implemented separately – voice volume depends on the distance between characters. The feature can be turned off if you want.

Because a large group makes Dark Souls II noticeably easier, the author added extra difficulty settings. You can change enemy scaling, and an optional Cursed Soul Fragment mechanic buffs enemies after player deaths. If there are too many deaths, a special Disaster state can begin in the world.

Invasions are supported too, but the host decides whether to allow or block them through the settings.

The mod runs separately from official multiplayer

Seamless Co-op doesn’t connect to FromSoftware’s standard matchmaking servers and uses separate save files with the .co2 extension instead of the usual .sl2.

According to Yui, this means that with normal use the mod shouldn’t get you banned in the official game. The author does warn separately: you shouldn’t move a modified save back into regular Dark Souls II – that could already cause problems with the anti-cheat system.

There’s another important limitation: the mod supports only the 64-bit PC version of Dark Souls II: Scholar of the First Sin. The original 2014 Dark Souls II with its 32-bit client isn’t supported, and Yui doesn’t plan to release a separate version for it.

The author also warns that the current build is still an early alpha and is likely to have sync errors, problems with enemy AI and other bugs.

Yui previously created Seamless Co-op for Elden Ring and similar projects for other FromSoftware games. The scheissgeist/Seamless repository that’s circulating online is not related to his Dark Souls II version: back in the spring, Yui separately asked the author of that project to rename it, since users had started confusing the two different projects.