The Marauder has a chance to go berserk at the start of each turn when enemies are present, or when enemies appear.

If he is able to control himself, he remains in a berserk state and gains 1 attack until the end of combat.  The Marauder's chance of controlling himself increases as he increases battle elevel, and as he kills enemies in each round of combat.

There is a chance that he is unable to control himself and swings wildly, damaging adjacent warriors and preventig him from taking any actions for the remainder of turn.