OpenXcom Co-op Mod v1.31.0 – Beta Release
Pre-release
Changelog 2025/11/01
During the past month, synchronization across the Battlescape has been reworked almost completely. AI synchronization is still in progress, so a few issues may remain and will be fixed later.
Shooting, movement, and death now synchronize much more reliably between players. Previously a shot could hit the UFO for one player but miss for the other, or an XCOM soldier could appear alive for one player but dead for the other. This “ghost soldier” problem has been fixed.
Projectile coordinates now synchronize to ensure that hits register the same way for everyone. Tile damage is synchronized as well. Panic and berserk states are synchronized so units walk to the correct tile and can drop their weapon correctly.
The issue where units did not move anywhere when path preview was enabled has been fixed.
The host now fully controls the client during AI turns, and the client no longer runs its own logic. This eliminates cases where units teleported or moved incorrectly.
In PvP the opponent no longer hears footsteps when a player is sneaking. The end-of-battle screen has been corrected. If the UFO side wins it shows Craft Lost, and if XCOM wins it shows UFO is recovered.
The settings menu now includes a Multiplayer options section. You can set a key to open chat and allow research synchronization in campaign mode. Many players have felt research synchronization is too strong, so it is now a setting. More options may be added later.
Some players experienced melee attacks and shots always missing. This was caused by random generator synchronization happening at the wrong time. That synchronization has been removed, and the random generator now behaves the same way as in the original X-COM.
Next we will continue improving AI synchronization and show the end turn screen on the client. Our goal is to keep multiplayer changes as close as possible to the original X-COM behavior.