TL;DR: More than a decade after its original release, Dark Souls II is set to receive a significant fan-made multiplayer update. A modder is currently working on a new "seamless" co-op mode that would theoretically allow the game to be played from start to finish in a single, soul-crushing session.

A well-known FromSoftware modder named "Yui" is working on a new seamless co-op mode for Dark Souls II. The mod is planned for release on the Scholar of the First Sin edition, which includes all previously released DLC and several enhancements to the base game. In a recent post, Yui said the project is taking longer than expected, as Dark Souls II has proven to be a challenging reverse-engineering effort.

Initially announced in 2025, the mod is now approaching the stability required for an "alpha" testing phase. Yui confirmed that it has become one of their most complex and ambitious projects to date, noting that Dark Souls II is a very different beast compared to other FromSoftware Soulslike titles.

A seamless co-op mod is designed to let players cooperate and complete a game without the traditional restrictions of official multiplayer modes implemented by FromSoftware. In theory, up to six players could progress through the entire game in a single co-op session, persisting through death and carrying world progression with them.

The mod will require the Scholar of the First Sin edition of Dark Souls II, which is a 64-bit upgrade of the original 32-bit base game. Yui previously worked on several mods for other FromSoftware titles, including Dark Souls, Dark Souls III, Sekiro, Elden Ring, and Elden Ring: Nightreign. These games are built on a broadly similar engine architecture, making it relatively easier to understand their systems after working on any one of them.

By contrast, Dark Souls II appears to use a separate branch of FromSoftware's proprietary engine. As a result, Yui effectively had to reverse engineer the game from scratch, which explains why development of the co-op mod has taken considerably longer than expected.

The mod is not yet complete, but Yui released a short video to announce the upcoming project and demonstrate that it is technically feasible. The developer plans to provide a test build of the mod for free, while bug reporting and support will be limited to project supporters via Patreon.

Dark Souls II was released in 2014, further expanding the "Soulsborne" formula introduced in Demon's Souls and Dark Souls. The game was a critical and commercial success, and FromSoftware went on developing even more punishingly hard action-RPG titles until Elden Ring: Nightreign came to be. Elden Ring was so successful that they are now making a movie out of the game.