Bloody knuckles is a two player game usually played by people during extreme boredom, or by the less intelligent among us for fun. The game requires some kind of coin and two people (with at least one hand per person). The first person to go flicks the coin so it spins on it's side. The other player must touch it without causing it to fall on the heads or tails side. Then the person who spun the coin tries touching it. This continues until the coin falls.

Example: The first person spins it, the second person touches it, then the first person touches it. The first person is safe since they touched it without the coin falling. Now, if the coin falls before the second person can touch it again, the second person loses. The second person must touch the coin before it falls. However, if when they touch it, it falls, they lose anyway.

Once someone loses, he or she must push his or her fist flat against the table top so that the knuckles that connect your fingers to your palm are facing forward. The winner takes the coin, and while keeping the coin flat on the table, flicks it (so it's not like the first time when he or she wanted it to spin on its side). The goal is for the coin to hit the loser's exposed knuckles with enough force to cause bleeding. Once this is done, the winner spins the coin again, and a new round starts. The overall loser is whoever quits first due to excessive boredom or pain.

Most coins can be used. Nickels hurt the most because of their sharp edges. Quarters, dimes, and pennies are smoother and hurt less, but are usually either too heavy or too small.