How to Host an Attack On Titan Final Stand Server

Start with 5 GB of RAM. That's the recommended floor for Attack On Titan Final Stand on Fabric 1.21.1 — the ODM gear physics, titan encounter scripts, and Survey Corps progression systems all run alongside the base pack, so going lower tends to show up as grapple stutter and titan AI lag before anything else does.

Import the modpack through a proper modpack install flow rather than copying a client export onto the server. Attack On Titan Final Stand ships specific Fabric mod versions for the ODM gear and titan systems, and a client-side export often carries client-only mods that don't belong on a server install.

Watch the server logs on first boot until Fabric reports every mod loaded cleanly — ODM gear registration and the titan spawn system are the two to watch for, since a missing dependency there usually throws on startup rather than failing silently later.

Only open the server to players after that first boot has finished cleanly with no errors in the log. Letting players log in mid-boot, while ODM gear and titan systems are still registering, is the most common way this pack ends up looking broken when it isn't.

Take a backup before importing a world, updating the Fabric loader, or changing configs. A bad import or a loader mismatch can wipe Survey Corps rank progress and any ODM gear upgrades players have earned, and those don't come back without a backup.