Snake eyes is a term used in gambling that specifically refers to rolling the dice in a game of Craps and only getting 1 pip on each die. The pair of pips resembles a pair of eyes, which is appended to the term 'snake' because of the long-standing association of this word with treachery and betrayal. The dictionary of etymology traces that use of the term back to 1929.[1] In modern parlance, it refers to such a roll in any game involving dice.

Because this is the lowest possible roll, and will almost surely be a loser, the term has been employed in a more general usage as a reference to bad luck.