Definition of moccasin game in US English:

moccasin game

noun

Canadian
historical
  • A gambling game originating among North American Indians (especially in Canada), in which players attempt to guess the number of small objects hidden in a moccasin; (also) a game in which an object is hidden inside one of several moccasins, and players attempt to guess which one.

Origin

Mid 19th century; earliest use found in Charles Lanman (1819–1895).