The History of Blackjack
Games of reaching 21 are old: the first written mention is in a book by Miguel de Cervantes, and around 1899 the American form was named blackjack.
Twenty-one
Card games in which you try to reach 21 without going over are old: the first written mention is in a book by the Spanish author Miguel de Cervantes. The German 17 and 4 comes from the 18th century and was very popular in France at the court of Louis XV. The French vingt-et-un (21) comes from the older trente-et-un, where 31 was the target. In German it was once also called Hopsen. With the 32-card values, 17 and a King (4) make exactly 21.
Blackjack
In the United States an American form of twenty-one developed into a game of its own and was named blackjack around 1899. The often-told story of a bonus for an Ace with a black Jack is a myth according to the historian Thierry Depaulis. Traditionally, a blackjack pays 3 to 2, and if the points are equal the bet is returned.
Blackjack at PaperGames
PaperGames plays with chips only: they are simply points in the game and cannot be exchanged for anything. The bank always follows the same fixed rule, the cards are shuffled anew for every round, and your points are always shown - the cards are told apart by filled and hollow suit symbols, so the game works on black-and-white e-ink.