When Blackjack first came to the US hundreds of years ago, many casinos decided to add some extra excitement to the game by offering 10-1 bonuses on winning hands including either the ace of spades, a jack of spades or a jack of clubs, or, in other words, a black jack. Whilst the aim of the game is to get to 21, winning with the bonus bet became hugely popular amongst fans of the card game - who then proceeded to refer to the entire game as ‘blackjack’. And even though casinos have since stopped issuing the bonus (although some now offer it in the form of a side bet), the name appears to have stuck.