This mutator adds a persistent levelup system to UT2004. Frags will give you EXP towards a levelup. After a levelup, you get a (configurable) number of points to use on statistics such as weapon speed, health, adrenaline, and damage modifiers or abilities such as Regeneration. Bonus EXP is given for killing players of higher level than you, multikills, sprees, headshots, winning a match, and (in certain gametypes) scoring game objectives. Every player's level, stats, and abilities are all saved to .ini and reloaded in future games when that player joins. As if all that wasn't enough, UT2004RPG features magical weapons and artifacts. Any weapon you pick up has a chance of being magical and having special modifiers, such as increased damage. Additionally, artifacts are special pickups placed randomly throughout the level which can be activated to give an ability or bonus. Artifacts consume your Adrenaline when in use.
Works with ballistic weapons by the way, as explained in a yahoo answer if you google "weapons of evil sentinal ballistic weapons mod." So not only does it add functionality that makes UT2004 a platform for a new kind of experience - with persistent stat choices - but it ALSO works with some other mods! Disabling magic weapons might be needed for compatibility with weapons that reload.