Fixes loads of bugs, inconsistencies, and discrepancies. Restores, adds, changes, and improves some content for a more logical execution and appearance. Now better and improved, plus fully inclusive, with HQ maps, HQ music, high resolution patch, official DLCs, restored prerelease content, and other game improving mods.
Found on Terra-Arcanum.org, under UAP section. Visit it for more details, FAQ, and changelog. Also, the author has a donation button on that page, so make sure to drop them some coins, so they could introduce more improvements to this patch in the future.
Works with Steam/GOG/retail releases of Arcanum patched to the latest official v220.127.116.11.
To install, launch the installer and point to Arcanum's clean installation directory, and then launch the game as usual.
Starting a new game is obligatory.