John Carter of Mars
This is the big one. John Carter of Mars – Modiphius’ lavishly illustrated RPG, with the official backing of Edgar Rice Burroughs estate. It uses the same 2d20 system that their other games use (Conan, Star Trek). They’ve published multiple supplements, miniatures, tile sets, and a GM screen.
Warriors of Mars: The Warfare of Barsoom in Miniature
In 1974, Gary Gygax and Brian Blume put out wargaming rules for Barsoom, including individual man-to-man combat. You can get it for free at the Internet Archive.Dungeons & Dragons: Warriors of Mars
Savage Mars
Edgar Rice Burroughs’ Mars: Shadows of a Dying World (An OGL Guide to Monsters, Races, and Beasts)
work with most D20 systems.Heroes of Mars
A Dream of Mars
Little Red Goblin Games has a cheap ($1.00) adaptation of Barsoom for Pathfinder
Lords of Mars
Warriors of the Red Planet
Night Owl Workshop puts out several games using Original D&D-style rules for variety of genres, including Warriors of the Red Planet. It’s set on a thinly-disguised Barsoom. It has rules for airship combat, underground exploration, and sorcery. It has a particularly nice “Appendix N” section, listing almost every Sword & Planet novel ever published, including a lot of obscure stuff more casual fans probably haven’t heard of.Revelations of Mars
Exile Games had an expansion to their Hollow Earth Expedition set on their pulpy version of Mars, using their Ubiquity system.Cavaliers of Mars
Onyx Path Publishing’s fantasy Mars setting.Mars
Adamant Entertainment put out two versions of this. One is a D20 version, the other is in Savage Worlds.GURPS Mars
B/X Mars
Setting for old-school D&D\OSR games. Lovely B&W illustrationsSpace 1899
***UPDATE – Almost forgot, the original D&D, specifically Book 3 – The Underworld & Wilderness Adventures does include an encounter table for Mars, for both animal and human encounters
***UPDATE 01/20/2020
I’ve gotten a bunch of suggestions from Reddit and elsewhere. Thanks to everyone for the suggestions
Rocket Age – Blood Red Mars
Rocket Age’s Mars is clearly Barsoom-like with an ancient, dying Martian civilization.
https://www.drivethrurpg.com/product/123288/Rocket-Age–Blood-Red-Mars
Suggested by roninnemo from Reddir/rpg
Thought Lords of Mars
This one looks out of print as far as I can tell. I think it’s a supplement for John Harper’s Danger Patrol
https://www.nobleknight.com/P/2147759277/Thought-Lords-of-Mars
Suggested by omnihedrom from reddit/rpg
Adventures on Dungeon Planet
A supplement for Dungeon World that helps to create a Sword & Planet like world. Easily adaptable to Barsoom
https://redboxvancouver.wordpress.com/dungeon-world-stuff/
Suggested by J_Standberg on Reddit/rpg
Jarkoon – Adventures on Planet X!
An OSR game for Sword & Planet
https://www.drivethrurpg.com/product/254446/Jarkoon–Adventures-on-Planet-X
Suggested by Simon W at gamingtavern.eu
Swashbucklers of Mars
A Searchers of the Unknown hack available for free at
https://retroroleplaying.com/content/searchers-unknown-rpg-collection/
Suggested by RedwoodRhiadra at reddit/rpg
Under the Moons of Zoon
This is its own light RPG system, with a strong Burroughs influence on the world.
https://www.drivethrurpg.com/product/119991/Under-the-Moons-of-Zoon
Suggested by RedwoodRhiadra at reddit/rpg
Distant Worlds
The Pathfinder supplement Distant Worlds lists some of the other planets in the Pathfinder universe. One is Akiton, clearly a take on Barsoom.
https://pathfinderwiki.com/wiki/Akiton
https://paizo.com/products/btpy8qib?Pathfinder-Campaign-Setting-Distant-Worlds
Suggested by high-tech-low-life on Reddit/rpg
Update *** 01/21/2020
Found this one. It’s a free add-on to the man-to-man tactical game Swordplay. It’s more of a wargame than a RPG, but it’s close enough.
It’s called John Carter For Swordplay (free PDF)
Update *** 2/13/2020
Goodman games put a series of adventures for Dungeon Crawl Classics called the Purple Planet series. It’s set on an dying alien world, with a clear Barsoom influence.
Suggested by hodaza on Reddit/rpg
Update *** 03/29/2020
Planets of Peril: The Sword & Planet Role Playing Game
This is Keith Vaughn’s sword & planet adventure game – much of it is Barsoom-inspired.
https://www.drivethrurpg.com/product/99255/Planets-of-Peril-The-Sword–Planet-Role-Playing-Game
Suggested by the author in the comments below.
Update *** 6/6/2020
Iron Lords of Jupiter
A D20 Modern setting published in Dungeon Magazine – issue 101
https://archive.org/details/Dungeon_Magazine_101
Update *** 6/14/2020
John Carter, Warlord of Mars
A RPG put out by Heritage Models, Inc. in 1978. It’s currently out-of-print, and I don’t believe there’s a PDF available anywhere.
https://en.wikipedia.org/wiki/John_Carter,_Warlord_of_Mars_(role-playing_game)
Update *** 06/18/2020
Sword & Planet: An Old School Roleplaying Game of Planetary Romance
This is an OSR game by Jason “Flynn” Kemp designed for general Sword & Planet adventures, but the core rules are designed around Barsoom.
You can get a free rough draft version at https://flynnwd.blogspot.com/2012/03/fantasy-friday-sword-planet-rpg-first.html
Update *** 06/28/2020
Deserted Cities of Mars (article)
Not a full game, but an interesting article in the August 1975 edition of the Strategic Review, the gaming fanzine TSR put out before Dragon magazine. Its called the Deserted Cities of Mars by Jim Ward. It’s got a description of the ancient cities of Barsoom, along with some generation tables.
Update *** 10/11/2020
Pulp Triumphant: Red Planets & Dark Jungles
Knight Owl Publishing recently put out Pulp Triumphant, a pulp adventure RPG. It has several settings, including one called Red Planet. It’s clearly Barsoom, even using the same names for cultures and creatures.
https://www.drivethrurpg.com/product/299397/Pulp-Triumphant-Red-Planets–Dark-Jungles
Update *** 04/06/2021
Bad Barsoom: A setting for Troika!
Here’s one I actually created – Bad Barsoom. It’s a short setting for the Troika! role playing game. It’s set on Barsoom in a future age, after the death of John Carter and Dejah Thoris. It’s not entirely serious – Cathoris XI is the corrupt Jeddak-For-Life, propped up by Jarsoomian military advisors. Tharks have become gangsters. Most Red Martian princesses and princes are social media influencers who fake their own kidnappings for sport. It’s a PWYW booklet in the PocketMod format. I’m thinking of expanding on the world into a full Troika! supplement.
https://ng76.itch.io/bad-barsoom
Barsoom: 1960
I’ve updated and expanded my Bad Barsoom setting to a full Troika! supplement:
https://ng76.itch.io/barsoom-1960
Update ***05/06/2021
Life on Barsoom
Here’s a free adaptation of Barsoom for the Advanced Fighting Fantasy system by Alessandro Viola
Life on Barsoom PDF (Link to PDF on Arion Games website)
suggested by user gruelove on Reddit
John Carter: Warlord of Mars
This 1979 game from SPI is a lot closer to a wargame than a RPG, but I believe it has enough RPG-like elements to count. In addition to running armies, players can play individual heroes, get invloved in treachery and romance, and rescue princesses.
Warlord of Mars (Board Game Geek site – PDF files are available for download)
Suggested by Neal Sofge in comments
Polyhedral Nonsense 
Checkout Lords of Mars:
https://rayotus.itch.io/lords-of-mars
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Thanks, but I think I’ve already listed that one.
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Oh, so weird. I read the article and did a search for it. How did I not see it?
Anyways, great post!
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Doesn’t Night Owl also have a Mechanized Men of Mars? Yup, just found it as PWYW here: https://www.drivethrurpg.com/product/182983/Mechanized-Men-of-Mars
There was also a Barsoom Glossary that I know DMs found helpful, the HTML page is here, but there’s a PDF linked maybe half-way down the page that I have: http://erblist.com/abg/index.html
Great project! Good luck,
–Ron–
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I believe Mechanized Men is an adventure for the already listed Warriors of the Red Planet. Thanks for the glossary link. That’ll be useful.
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Great and thorough list. I’ll remember this if somebody is thinking to run a Barsoom game.
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Years ago I put up one on rpg.now called Planets of Peril: The Sword & Planet Role Playing Game. It’s brought in several hundred dollars to me so it’s had some success. It’s more of a generic planetary romance game but one of the moons to adventure on was modeled on barsoom/mars
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Thanks. I’ll add it to the list
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Not sure if it would be considered a full rules system, but a list this comprehensive should also include the Grim Tales/d20 sourcebook Slavelords of Cydonia
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What about the SPI John Carter Warlord of Mars game? It’s a unique concoction of wargame technologies attempting to coalesce into an RPG-like thing. Way, way out of print but someone’s recreated the components for download on BoardGameGeek.
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Interesting. I thought that was entirely a wargame, but looking at the rules, you’re right – it does have a lot of RPG elements. I’ll add it to the list. Thanks.
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