You can download the standalone v1.5.0.13 installer or use the GOG Galaxy client to sync the latest version.
The game should update automatically if your settings allow it. You can force an update by right-clicking Battle Brothers in your library, selecting Properties > Local Files , and clicking Verify integrity of game files . Download Battle Brothers v1.5.0.13
Check your Epic Games Library for the update prompt under the game's tile. Patch Highlights & Changes You can download the standalone v1
This version is fully compatible with existing saves from any 1.5.x version. selecting Properties > Local Files