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Pin the tail on the donkey is a game played by groups of children. It is common at birthday parties and other gatherings. A picture of a donkey with a missing tail is tacked to a wall within easy reach of children. One at a time, each child is blindfolded and handed a paper "tail" with a push pin or thumbtack poked through it. The blindfolded child is then spun around until he or she is disoriented. The child gropes around and tries to pin the tail on the donkey. The player who pins their tail closest to the target, the donkey's rear, wins. The game, a group activity, is generally not competitive; "winning" is only of marginal importance. --Wiki

An example of the game after it was played.

The game can also be played by teenagers and adults, especially if the "donkey" is replaced with depictions of something or someone else. As a drinking game, the person with the worst tail pinning is awarded one shot of a selected alcohol, to be determined by house rules or the loser in a friendly environment. --Wiki