You can attempt to disarm your opponent in place of a melee attack. If you do not have the Improved Disarm feat, or a similar ability, attempting to disarm a foe provokes an attack of opportunity from the target of your maneuver. Attempting to disarm a foe while unarmed imposes a –4 penalty on the attack.
If your attack is successful, your target drops one item it is carrying of your choice (even if the item is wielded with two hands).
If your attack exceeds the CMD of the target by 10 or more, the target drops the items it is carrying in both hands (maximum two items if the target has more than two hands).
If your attack fails by 10 or more, you drop the weapon that you were using to attempt the disarm. If you successfully disarm your opponent without using a weapon, you may automatically pick up the item dropped.