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

<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 to your AC, adding the same number (+5 or less) to all melee damage rolls. This penalty may not exceed your base attack bonus. The penalty to AC and bonus on damage apply until your next turn. When wielding a two-handed weapon, you instead add twice the number subtracted from AC to damage. You can’t add the bonus from Reckless Attack to the damage dealt with a light weapon (except with unarmed strikes or natural weapon attacks), even though the penalty on AC still applies.
<php>echo “<b>Special:</b>”;</php> Reckless Attack can be used in place of Power Attack to qualify for a feat, prestige class, or other special ability. You cannot use both Reckless Attack and Power Attack in the same round.