Unreal Tournament 2003 added adrenaline to the UT gameplay - a feature that was carried into Unreal Tournament 2004. Killing enemies and picking up Adrenaline Capsules adds adrenaline points up to a maximum of 100. Capsules are worth two points, standard kills are worth 5 points, First Blood 15, and double/multi/mega/etc. kills an ever-increasing amount. When a player has 100, he can perform Adrenaline Combos using a key combo:
* Standard combos
o Speed - Faster Movement Speed and higher jumps (forward, forward, forward, forward)
o Booster - Health/armour regenerates up to the maximum 199/150 (back, back, back, back)
o Invisible - Invisibility (right, right, left, left)
o Berserk - Double rate of fire (forward, forward, back, back)
* ECE Bonus Pack additions
o Pint-Size - Character model shrinks (left, left, left, left)
o Camouflage - When crouched, character model is disguised as a static object (right, right, right, right)
Each combo uses up adrenaline, and each at a different rate. Once the adrenaline level reaches 0 the combo effect stops and the player must rebuild their adrenaline points back up to 100 to use another. Picking up more capsules or scoring more frags can allow you to maintain the combo a little longer. If a player's kill rate is high enough he can maintain a combo indefinitely.