In 1914 Edgar Rice Burroughs’ seminal classic A Princess of Mars launched the “Sword & Planet” genre and directly inspired Flash Gordon, Superman, Dune, Star Wars and many other characters and stories. Largely forgotten by the public to the point that the John Carter movie was accused of ripping off the very films the original book had inspired!
The Mars novels by Edgar Rice Burroughs were a major influence on the early D&D game. The original LBBs contain more references to Barsoom novels than to any other fantasy literature.
Some of the races and creatures even appear in the Wandering Monsters tables of OD&D.
Gary Gygax acknowledges this influence in the Forward to Men & Magic “These rules are strictly fantasy. Those wargamers who lack imagination, those who don’t care for Burroughs’ Martian adventures where John Carter is groping through black pits...will not be likely to find D&D to their taste”
Even in AD&D references to Barsoom are found throughout, including notably in Appendix N of the DMG.
The "Warriors of Mars" rules for miniature wargames, was published by TSR in July, 1974 just six months after the original D&D rules. Written and designed by Gary Gygax and Brian Blume, and lavishly illustrated with 24 interior drawings by Greg Bell.
They are a standalone set of rules for adventures on Barsoom. It is clearly not a roleplaying game, there just isn’t enough there in ways of creating or describing a character, but it does have some RPG like elements such as 1:1 combat and movement, character advancement levels, and suggestions how to make personal adventures. It is a wargame closer to Chainmail than to OD&D.
The forward by Gary Gygax states "this project was done at the request of the firm which originated the miniature figures for this singular aspect of wargaming". According to Jon Peterson's book Playing at the World the firm is identified as Hinchliffe Models which later became Heritage Models.
The Edgar Rice Burroughs estate contacted TSR with a cease and desist so to avoid any legal action, the book was never reprinted. Which is a shame as there doesn’t appear to be anything in Warriors of Mars that wasn’t already in the public domain. This makes this one of the rarest hard to find and most expensive TSR books. Copies come up occasionally on ebay for hundreds of dollars. PDF copies are easy to find online with a little searching.
The book is divided into Land Warfare, Aerial Warfare, and Characters, & Creatures, followed by a series of combat tables. There are also maps of Barsoom.
The Land Warfare section provides rules for mass combat, sieges, and rules for individual combat.
Individual melee involves rolling 3d6 and the result compared to attacker vs. defender on a rather dense table in the back which looks reminiscent of the Fantasy Combat table in Chainmail. There are 2 rounds of melee each turn.
Missile fire is a novel system: roll 2 dice, The first is the target number to match or beat in order to score a hit and it is modified by the attackers status, weapon, range, and so on. The second die is the roll to hit that target number.
Individual adventure guidelines describe unexpected encounters, time, and movement. A rudimentary experience and advancement system is described for characters to rise as high as 12th level. John Carter is 13th level. Fighting men and assassins are the only things mentioned that could remotely be considered “classes”.
The "experience" points table includes rewards for defeating foes, rescuing princesses, capturing airships, capturing enemy warriors or items, freeing prisoners, and finding lost treasures.
Adventure locations such as exploring deserted cities, or delving into the black pits beneath are only given a brief paragraph and a suggestion to consult D&D.
With movement rules, individual combat, experience, and encounter charts there is almost a proto rpg lurking in this game, but to turn it into one would take about as much effort as it would take to turn Chainmail into an RPG.
Aerial combat is given the most attention with rules for movement, fliers, fire, elevation & depression of guns, damage, ramming & collision, grappling, boarding, bombing, air-to-ground combat, fire at structures, and ground-to-air fire, with tables for resolving these combat situations.
The last section sparsely describes characters and creatures of Barsoom before going into the final tables and charts. Including John Carter, Ulysses Paxton, Carthoris, Tars Tarkas, Solon of Okar ,Mors Kajak, Tardos Mors, Kantos Kan, and the various martian races.
There are also short descriptions of the various creatures like white apes, darseen, malagor, and orluks. It mentions that other animals are not covered, since they are already described sufficiently in the novels.
"Warriors of Mars" is a standalone wargame, related more to Chainmail than to D&D, the enthusiasm for Barsoom shines through and this piece of gaming history provides a glimpse of what could have been if the tales of ERB had become the prominent backdrop for roleplaying adventures.