John Carter of Mars RPG: Core Rulebook - Rules of Play says:
Edgar Rice Burrough’s John Carter of Mars: Adventures on the Dying World of Barsoom transports you to the Red Planet of Barsoom, an arid, dying land of ancient civilizations and fearsome creatures. Begin your adventures of romance and heroism using a pulp-action inspired variant of the 2d20 System. Take on the role of heroes as you travel, battle, and romance your way across the wondrous and dangerous world of Barsoom. Play as John Carter, Princess Dejah Thoris, the fearsome Thark warrior Tars Tarkas – or create your own heroes from an exciting variety of options.