Roleplaying games using reality-based historical (i.e., before the last century) settings. Many such games have been published (beginning in 1975 with TSR's Boot Hill and GDW's En Garde!), but few have had any longterm success in the gaming market.
Set in 17th-century France, En Garde! is both the first 'swashbuckler' roleplaying game and the first RPG published by Game Designers' Workshop. The rules are currently published by Small Furry Creatures Press, and often used for play-by-mail campaigns.