Big Leagues (Fallout Supplement)
From D&D Wiki
BIG LEAGUES [Combat]
Swing for the fences!
Benefit: With each rank of this feat, melee weapon damage is increased by 2. The second rank disarms your opponent on a critical hit. Third rank gains an increased chance to disarm your opponent. Fourth rank hits all targets in front of you. Fifth rank deals double damage with a melee weapon, and gain a chance to cripple your opponent, or grand slam their head clean off (vorpal strike)!