Tales of Tolgard
Frenzy is a special ability that frenzied berserkers learn. It is similar to the rage ability that barbarians and dwarven battleragers with several important differences, although it can be used in conjunction with raging.
A frenzied warrior is stronger than usual and hits very hard. However, they have a harder time defending themselves and the frenzy itself is destructive to the warrior’s body and can actually make them lose consciousness. When someone is frenzied, they must attack whoever they perceive as an enemy each round. If they run out of enemies before they run out of frenzy, they will attack whoever is closest, even their own party members. It takes a great feat of willpower to stop a frenzy before it has run its course.