Cheating can be to create an unfair advantage, usually in one's own interest, and often at the expense of others. The term cheating usually refers to the breaking of rules but not laws; activities that are actually illegal are usually referred to as corruption or fraud.

A common occurrence of cheating is in education, where it takes a number of forms. Cheating can be on tests where a cheater can copy off another person, sneak in notes, or share information with others. On essays and assignments cheating most often takes the form of plagiarism. Cheating is considered both unethical and immoral by most, and faces stiff punishment if discovered. Nonetheless it is quite common.

Another sphere where cheating is not illegal but merits stiff penalties and opprobrium is in sport. This can include taking performance-enhancing drugs such as steroids.

Cheating can also mean infidelity, particularly adultery.

See also: Cheating in poker, Cheating in online games, Gamesmanship