You cause one of your hands to drop from your wrist and allow it to act semi-independently. This process causes you no pain. While separated from you, your hand counts in some ways as an independent creature, and in other ways as a part of you.
Your hand is considered to be a quadruped creature of a size category three smaller than you. Like all creatures, your hand has 10 hit points and base AC of 10, to which it adds its size modifier (+8 if you are Medium or Small), plus any armor class bonus you possess other than armor or shield bonuses. The hand can take a move action and a standard action each round, and it may make a single attack each round at your highest attack bonus.
The hand can deliver touch spells that you cast by touching the intended target the same round that you cast the spell, but it cannot cast spells independently. The hand uses your saving throws and has improved evasion. You retain the sense of touch from the severed hand and you can feel anything your hand can feel.
When acting independently, your hand can move as far from you as desired, but you must direct your hand. If the hand goes out of your sight range, it is effectively blind; if it goes out of your hearing range, it is effectively deaf.
While you are missing your hand, you cannot do anything requiring two hands (such as using two-handed weapons or holding two different weapons), and you suffer a –4 penalty to the following skills:
Acrobatics, Climb, Craft, Disable Device, Disguise, Escape Artist, Heal, Open Lock*, Sleight of Hand, and Swim. Despite the name, your hand is severed and does not count as free for the purpose of spells with somatic components.
If the hand is destroyed, dispelled, dismissed, or at the end of the spell’s duration it reappears attached to your wrist.
Focus: A loop of string tied around your wrist.
*Editor's Note: This spells references the Open Lock skill. In the Pathfinder system, this skill has been incorporated into the Disable Device skill.