Two players face each other and grab their opponents hands (opponent #1's right hand to opponent #2's left hand, opponent #1's left hand to opponent #2's right hand, interlocking fingers or thumbs with fingers wrapped around an opponent's back part of the hand). On the word "go", each opponent attempts to bend the other's hands back and inflict pain by straining the ligaments and tendons in the wrist. When a player can no longer stand the pain, or reverse the situation by overpowering the other player and bending back their wrists, the player cries out "Mercy!" (or "Peanuts!", "Danny Stavros Buck", "Pinochle" or "Uncle" in some areas) and is then defeated. The players then disengage hands and match is completed.
In some areas, Mercy is usually one-handed, with both players using either their right or left hands. In this version, the use of the other hand at all is considered cheating. There is also often a focus on bending the opponent's arm as well as hand. Skilled Mercy players often use specific strategies to get their opponents into painful positions, such as twisting the arm around so that the elbow is pointed towards the neck, against the back, and then pushing up on the arm.