We may all recognize the game Battleship. But few likely know that Battleship began as a paper and pencil game, played exactly the same as the plastic or electonic versions. The game belongs to a family of strategy games developed around the turn of the 19th century, in which each of two players plots positions unknown to his or her opponent. Opponents must guess where to "fire" or drop a "bomb." Battleship's direct precursor was another paper and pencil game called Salvo. The play is virtually the same as the later game. As a game, Salvo existed as a public domain game--anyone could play it with simple graph paper. However, several firms produced pre-printed versions over the course of the 20th century. A veteran of both World Wars devised a printed Salvo game in 1942, forming a game company with a partner and printing up pads of the battle grids.