ELDEN RING Seamless Co-op

What it is

ELDEN RING Seamless Co-op is a free, open-source mod developed by LukeYui (with contributions from the Seamless team) and distributed via Nexus Mods + GitHub. It enables up to 6 players in a persistent world, with shared progress and without vanilla co-op barriers.

Released in March 2023, it's the most-downloaded Elden Ring mod (~3M downloads) and practically the reason many players started installing mods on the game.

What it solves

Vanilla Elden Ring co-op has limitations designed to preserve single-player difficulty:

• You summon a Phantom and they leave when the area boss dies.
• Phantoms can't ride Torrent.
• The open world has invisible fog walls that limit distance.
• Invasions can kill your session.
• Quest and map progress isn't shared.

Seamless Co-op removes all of that. You and up to 5 friends share a world: kill bosses together, explore without barriers, ride horses, no invasions (unless you toggle them on), and progress persists between sessions.

What people use it for

Full run with a friend: start Elden Ring from scratch together, without Phantom mechanics cutting sessions.

4-6 friend co-op: up to 6 players in the same world, adjustable difficulty scaling via settings.

Open world exploration: ride Torrent in a group, discover areas together with no restrictions.

Boss rushing with friends: re-fight specific bosses multiple times to farm or practice.

SOTE in co-op: the mod supports the DLC; you can run Shadow of the Erdtree fully grouped.

Who shouldn't use it

If you play on console (PS5/Xbox), the mod doesn't exist — Seamless Co-op is PC-exclusive.

If you want to keep your character compatible with vanilla online, you can't — the mod forces offline mode (anti-cheat).

If your plan is PvP/invasions, Seamless Co-op doesn't apply — the mod disables invasions by default.

If the "Souls intended" co-op idea (ephemeral Phantoms, preserved difficulty) appeals to you, don't touch the mod.

How it's used in practice

1. Install Mod Engine 2 first (Seamless Co-op uses it as a base).
2. Download Seamless Co-op from nexusmods.com/eldenring/mods/510 or github.com/LukeYui/EldenRingSeamlessCoopRelease.
3. Extract files following the README — includes a dedicated launcher.
4. Define a shared password for your group in seamlesscoopsettings.ini.
5. Launch the game with launch_elden_ring_seamlesscoop.exe.
6. You and your friends use the same password — connect automatically when in the same area.

Honest limitations

Version-locked to the game patch: when Bandai patches ER, Seamless takes 1-7 days to update. During that window, you can't play.

Offline only: your Tarnished becomes "tainted" (community terminology) — you can't go back to vanilla online with that character. Workaround: keep a separate save for mod vs online.

Controversial difficulty scaling: the mod scales boss HP for groups, but feel is that some fights become trivial and others stay frustrating. Tweakable via settings but requires experimentation.

Basic netcode: lag and desyncs happen especially with 5-6 players. For 2-3 people the experience is stable; for 6 it fluctuates.

Quest-specific bugs: some NPC quests (Ranni, Millicent) have quirks in co-op that may need workarounds.

How to start

1. Make sure you have Mod Engine 2 installed first.
2. Visit nexusmods.com/eldenring/mods/510 and download the latest version.
3. Extract files following the README.
4. Edit seamlesscoopsettings.ini with a unique password for your group.
5. Coordinate with friends to use the exact same mod version.
6. Launch with the Seamless executable and start playing.