Rage Of The Norsemen
Vikings that are berserks (not true berserks) may spend a round to call up their rage which puts them in a berserk state that functions as follows:
the Viking will “Berserk” for one round for every two levels of experience and gain an extra 4 levels (+4 to hit, no hit points, but may benefit from additional attacks). Regardless, during this phase they can function until –10 + level in hit points. After combat or berserk period has ceased they will die if below –10 or go to 0 hit points if between –10 or and -1 (but below 1 hit point). While berserking, all damage to the Viking is at –1, the Viking is immune to fear but also takes a –2 penalty on all saves, no dex AC bonus and cannot run but must fight until the berserking fever is over. After berserking they must rest for one round for every two rounds berserking immediately or lose 1 hit point per round until doing so.