What has to be broken before you can use it?

The answer to the riddle, "What has to be broken before you can use it?" is an egg. This riddle appears in popular applications, such as "Guess the Riddle" on iTunes.

Riddles are not specific to any one country or culture, but are found throughout the world. Archaeologists can trace riddles as far back as thousands of years to Tibet, China and Japan, where they discovered puzzles carved on the walls of caves and temples. Sometimes these etchings involved mathematical formulas, but many were merely to provide entertainment. Some strategy board games, such as chess, have developed from early riddles.