Bloodlust

Bloodlust is one of Fallout GURPS disadvantages. See: Fallout GURPS.

Overview
"A character with this disadvantage suffers from a strong desire to see his foes dead. He must go for killing blows in a fight, put in an extra shot to make sure of a downed foe, choose violent and messy options when stealth might be better, etc. An IQ roll is necessary to accept a surrender, or even take a prisoner under orders. And a player who always tries to make this IQ roll may be judged guilty of bad roleplaying!"

- Steve Jackson Games GURPS sources

In Fallout
With the abandonment of GURPS, Bloodlust was recycled, image used for the Berserker reputation.