You can make exceptionally powerful melee attacks at the cost of accuracy.

<php>echo “<b>Prerequisites:</b>”;</php> Str 13, BAB +1
<php>echo “<b>Benefit:</b>”;</php> On your action, before making attack rolls for a round, you may choose to take a penalty of up to -5 on all melee attack rolls, adding the same number (+5 or less) to all melee damage rolls. This penalty may not exceed your base attack bonus. The penalty on attacks and bonus on damage apply until your next turn.When wielding a two-handed weapon, you instead add twice the number subtracted from attack rolls to damage. You can’t add the bonus from Power Attack to the damage dealt with a light weapon (except with unarmed strikes or natural weapon attacks), even though the penalty on attack rolls still applies.