Unearthed Arsenal is Micro Star’s unauthorized expansion for Blizzard’s game
Diablo. It promises new weapons, classes, and utilities to augment a
registered copy of Diablo.

The main feature of Unearthed Arsenal is a character hack utility that allows
the editing of stats and abilities. This along with a few new magic items and
some “new” (edited) character classes tried to fill a need for amateur quality
user mods before the internet was widely available to everyone.