Gamble descends from Old English gamen meaning 'joy, sport, game'. It originally meant 'to play' — the association with wagering money developed only in the 18th century. Game is its direct sibling.
To play games of chance for money; to take a risky action in the hope of a desired result.
From an earlier form gamel, gamble, a dialectal variant of Middle English gamenian meaning 'to play games', from Old English gamenian meaning 'to play, to amuse oneself', from gamen meaning 'game, joy, sport, pleasure'. The Old English gamen derives from Proto-Germanic *gamaną meaning 'participation, communion, togetherness'. The gambling sense — playing specifically for money — developed in the 18th century. Before that, to gamble was simply to play. The word game itself is a direct descendant of the same Old English root.
Gamble and game come from the same Old English word gamen, meaning 'joy' or 'pleasure'. To gamble was originally just to play — the money came later. Backgammon also contains this root: it likely comes from Middle English 'back game', a game where pieces are sent back to the start. Even gambit, a chess term, may be influenced by this word family through