Deuce was first used in 17th-century English in various exclamatory expressions in which it was equated with ‘bad luck’ or ‘mischief’, because in dice-playing two (= deuce) is the lowest and most unlucky throw. From this there soon developed the sense of deuce as ‘the devil’ (i.e. bad luck or mischief personified). Deuce as a euphemism for the devil occurs in a number of expressions, including those above.