Power Attack

Effect: 

Once per battle before you roll an attack, you can declare you're using Power Attack to deal additional damage with that attack roll. If the attack hits, you deal the following additional damage:

Deal 1d4 additional damage per level if you are using a one-handed weapon.

Deal 1d6 additional damage per level if you are using a two-handed weapon.

Adventurer Feat: 

You deal the additional Power Attack damage even if the attack misses.

Champion Feat: 

One battle per day, you can use Power Attack twice in the battle.

Epic Feat: 

One-handed weapon damage using Power Attack increases to 1d6 per level; two-handed weapon damage using Power Attack increases to 1d8 per level.