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John Carter of Mars Core Rulebook $19.99
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John Carter of Mars Core Rulebook
Publisher: Modiphius
by Daniel A. [Verified Purchaser]
Date Added: 11/08/2019 00:31:27

See Molly's full review HERE

The world-building aspects of the JCOM RPG are genuinely quite good. A lot of effort went into it, helped along by the fact that there are 11 books and a substantial number of comics to build off of. This results in a few things that lead to a rather open-ended experience for those wishing to create a game.

First of all—and this is quite clever and helps to avoid a common issue in doing a licensed RPG—there are three eras of the world that you’re able to set your adventure in. One is set when the titular character first arrives, before he started making waves, thus allowing you to set your adventures years before he showed up without issue. Another is set during the time when John Carter was established but not quite viewed as the savior of all of Barsoom, and thus allows you to set up your own reputations, or even build a kingdom, without worrying about upsetting him. And the third is set when John Carter rules all of Barsoom, which makes making a name for yourself difficult, but allows for the most interaction with canon heroes if that’s your thing.

And that era system applies to the races you can play as too. There are five races you can play as; your backstory, culture, and how NPCs react to you will all change based on which race and what era. For example, a Green Martian from the early era will come from a very grim and almost Objectivist society, but as time passes they become a much more open and friendly people. The Okar (Yellow Martians) will be very isolationist and arrogant in the early eras, with only a vague idea of what’s happening in the rest of the world outside of their cities, but will be more involved and informed in later ones. Things like that.

It’s honestly a rather good setup. There’s enough to give both the player and the DM (here called the Narrator) plenty of information and a firm foundation (heck, there’s a not insignificant portion of the manual devoted to the history of the planet, and the cultures of the various factions of the races) but allowing for freedom to make your own choices and not be rail-roaded by the canon too much.

[4 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by Jay S. A. [Featured Reviewer]
Date Added: 06/24/2019 10:19:23

The John Carter of Mars RPG comes out at a time when there is a great demand for games with laser-focused mechanics that know exactly what kind of experience they aim to deliver. While built upon the existing 2d20 framework, the team was able to craft a quick, punchy, and perhaps most important: authentic John Carter experience with this game.

Layout and Artwork

John Carter of Mars is published in a non-standard landscape format that works well for such a cinematic game. I imagine that the physical format of these books is impressive as heck, and I eagerly await the copies I ordered a few weeks back.

The artwork is beautiful, and portrayal of the Red Martians is tasteful as opposed to other portrayals of their clothing in other materials. I’m honestly relieved as I’ve had the hardest time getting my wife interested when all she gets in Google Image search are pinup artwork of Dejah Thoris in exceptionally revealing attire.

Also cheers for Francesca Baerald’s gorgeous character sheets! There is no excuse to not use the colored versions.

The Rules

Not only do the game mechanics read well, they deliver the power-levels expected of these larger-than-life heroes, for which death defying adventures are the norm. Paired with design choices that highlight these, (like the lack of cover rules) the players are guided both mechanically and thematically towards the genre it was meant to run.

The Setting

The game also handles the potentially problematic elements of the game with surprising grace, framing John Carter’s adventures and characters in a way that makes sense in a day and age where we’re more aware of issues such as sexism and racism, without detracting in any way from the source material.

For fans of the setting, the RPG also delivers on the depth of analysis that discusses the social norms and cultures of the various societies in Barsoom in a way that rings true. There’s never this sense that the designers just built the rules and left you the hard work of world building or baking in the feel of the game.


Fast, fun, but backed with a solid framework of the 2d20 mechanics, John Carter of Mars the Roleplaying Game is one of those games that reaches out and seizes the GM’s imagination, demanding to be played.

Much like it’s titular hero, the game cuts down any and all opposition that gets in the way of the primary goal of being able to play a fun, swashbuckling adventure game. Streamlined mechanics, and a focus on Renown as a means of denoting advancement leaves player characters less worried about survival and has them looking forward to the next dire peril that the GM will throw at them next.

GMs, on the other hand, are given the keys to the kingdom, with an entire toolkit for making Sword and Planet adventures, and the means to run them right with confidence.

Overall, John Carter of Mars the Roleplaying Game is a must have for fans of the setting, and for those who are looking for something new, but with solid depth to its setting.

[5 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by Monica G. [Featured Reviewer]
Date Added: 05/11/2019 12:06:07

The John Carter of Mars series by Edgar Rice Burroughs is perhaps best known for the notorious 2012 film adaption (the infamous 'mockbuster' film company The Asylum also took a stab at the character three years earlier). But the series also influenced such new classics as Star Wars and Avatar. The source material is a natural for a tabletop RPG and Modiphius Entertainment has provided it. How does it size up? The series features a Virginian native and soldier who seemingly dies in the nineteenth century and is temporarily transported to Mars (known to its inhabitants as Barsoom as chronicled in the 1917 book A Princess of Mars. A series followed and John Carter is now second only to Tarzan of the Apes as Burrough's most famous character. Although the game is faithful to the source material, the designers openly acknowledge that politically incorrect elements emerge in the original stories and are translated into the game. Context is obviously open to interpretation and players can still handle subjects such as slavery or sexism in the manner they deem appropriate.

The game allows characters to play either a transplanted Earthborn hero like Carter or one of four 'human' races populating Mars - Red Martians, Green (the most physically alien and my personal favorites), Yellow and Black. Character creation is relatively simple. Character start with four points in six attributes and are given to more points to discretionarily spend - more points are added based on the races and occupations selected by the players. Players combine two appropriate attributes as appropriate for skill resolutions using 2 D20 - the target number is equal to or less than the sum of the attributes. If a player rolls a success that is less than the weaker of the two attributes, they earn an extra success. The difficulty of the task determines the number of successes required - excess successes can be saved as momentum points and spent at a later time. The race and occupation selected also determines a character's general skills and knowledge of the setting. Each occupation also comes with a recommended talent (characters get the equivalent of five talents when they begin).

For example, I may want to play an Earthborn fugitive Confederate sharpshooter feeling Union regulators that winds up on Barsoom - basically The Outlaw Josey Whales in a sword-and-planet setting. He would three points two might and one each to two other attributes - I add a point each to reason and cunning. I have to subtract one from an attribute due to the racial choice so I deduct one from daring. I choose fugitive as an occupation because his character, like Whales, was more of a guerilla than a regular soldier and is now fleeing. I now get to add two each to cunning and passion. The talent 'no chains can hold me' is suggested as a talent but I can see what else is available and pick something else. Players choose a descriptor that describes the character and allows bonuses to attributes. I choose canny and get one point added to both daring and reason. Characters also start with at least one core piece of equipment and renown - the latter allows the purchase of in-game advantages such as contacts. Earthbound characters are the exception to both rules so I am out of luck. Each character also selects a flaw to help define them. Player-created flaws are allowed on a discretionary basis and I choose bitter - my character lost friends and family during the Civil War. For talents I pick three grade-one entries and one grade-two. I select passionate rider, expert rifleman and keen marksman for grade one. My grade-two selection is deadly pistoleer. Yes, I may I have watched too many Westerns. Characters also start with a luck point pool that is generated from their weakest attribute, although it can be awarded for player ingenuity. Game masters can use the player's luck pool to generate threat points, which are used in a manner similar to momentum except that they are used against the payers (these points can temporarily boost the villain's fighting capabilities, for example).

The setting is divided into three eras based around the progression of Carter's social influence. The first era, for example, is set before Carter became established and is a conflict-driven setting. During the third era, when Carter rules an empire, there is considerably more law and order. The rules also include a bestiary and a serialized adventure in the mold of the original stories. The book also discusses the shared universe of which the Mars series was just a part. Not only does Carter find monsters and villain on Jupiter and the moons of Mars but he occupied the same literary setting as Tarzan, the Pellucidar saga (essentially John Carter in a hollow Earth setting), the Venus series (really more of the same) and the standalone novel The Mad King (a Ruritanian in the style of The Prisoner of Zenda). Unfortunately, the rules only skim this aspect of the story - future supplements may address this. Overall this is an excellent product. It retains the integrity of the original material while allowing for significant extrapolation. This is highly recommended for fans of the Space Opera genre who want to try something more 'old school.'

Read the full review at!

[5 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by Stephen M. [Verified Purchaser]
Date Added: 04/26/2019 07:56:53

This is an absolute must buy for any John Carter fans. the spirit and tone of the original books are perfectly replicated in the modified 2d20 system. the removal of skils and focus on the talets is a good choice and fits the settign well. I probably would have given five starts, but I don't think there is enough information about the details of daily life of the base cultures, partiularly the green martians. I doubt that someone could pick this up and run a game without having read at least the first book of the series.

[4 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by Simon K. [Verified Purchaser]
Date Added: 04/17/2019 22:29:04

Set in the wondrous, dying world of Edgar Rice Burrough’s Barsoom, John Carter of Mars (JCOM) is a swashbuckling science-fantasy game of radium guns and longswords, airships and adventure. A solid rules framework emphasizes narrative play and encourages the action to keep moving forward.

Characters are created by choosing a race (one of 4 types of Martian plus earthborn humans), an archetype (airship pilot, explorer, duelist, etc.), a descriptor (primary personality trait), Talents (special abilities), and a Flaw (a personality trait that gets you into trouble).

Your choices from these options help determine your Attribute ratings (the core scores that define your character). Rather than a skill list, JCOM archetypes tell you what your character knows and is capable of, allowing characters to attempt related actions. These function similarly to Fate Aspects or 13th Age’s Backgrounds.

What’s particularly nice is the game includes notes on how to build or customize your own Archetypes, Descriptors, and Flaws, allowing a wider variety of options. This isn’t a massively in-depth section, as these choices are mostly ways to distribute points, but it’s nice that it’s included.

The game runs on a narrative version of the 2d20 system. As mentioned above there are no skill lists, so all justifications for attempted actions come from the various choices you make in character creation. Your duelist is perfectly able to hold their own in a swordfight, but might be at a loss in piloting an airship, or properly handling animals.

In previous versions of the 2d20 system the target number for a skill check was derived by adding your Skill Expertise to its respective attribute, rolling 2d20, and counting a success for each die that rolled equal to or under the target number. If the die roll was lower than the Skill Focus (starting levels typically 1-3), an additional success was gained.

In JCOM, the target number is found by adding two abilities together, and the “Skill Focus” is the lower of the two numbers. This means that adding two attributes rated 7 and 5 will give a target number of 12, and any die that rolls 5 or under will generate an additional success. Successes are compared to a difficulty rating (and if they match or exceed the rating the check is successful. Any successes in excess become Momentum, which acts as a meta-currency and can be saved in a pool or immediately spent to affect the narrative by adding additional dice to rolls, altering difficulties, or learning information, among a variety of other things. Due to the increased chance for extra successes, the PCs have a greater ability to perform fantastic and daring feats.

As an additional resource, players have Luck Points, which can operate in a similar fashion to Momentum, but also affect how much Threat the Narrator has access to. Threat is the Narrator’s meta-currency, which they can use to hinder the players.

Conflict and combat use abstract zones rather than precise movement and combat is not just restricted to physical conflict as it also includes social combat. Attribute tests are made to attack, with different pairings depending on the method, and resisted with attributes specific to the type of attack. Any damage is inflicted on the appropriate Stress Track.

As a reward beyond the traditional XP, Renown helps track the characters’ reputation and give them motivation to attempt great deeds. It can be used to gain social and political advantages, allies, influence, and titles among the lands and organizations of Barsoom. It gives a solid motivation to be involved in the welfare of Barsoom and encourage the players to effect change upon the setting.

There are thorough sections which detail the history and society of this fantastic world, as well as secrets of the setting, all ripe with plot hooks. While some players may already be familiar through the books, comics, or movie, it’s always useful to have the lore collected for easy reference. Unsurprisingly, events of the books are summarized, so expect spoilers.

Narrators are given useful sections on how to best emulate the pulp, planetary romance genre of JCOM. Campaign foci and structure, summaries and conventions of the genre are all highlighted. The strange world of Barsoom is fleshed-out with the bestiary, with the useful inclusion of plot seeds for each creature.

John Carter of Mars is a great version of the 2d20 system, exhibiting the versatility of the rules and bringing life to a classic setting and genre.

[5 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by Megan R. [Featured Reviewer]
Date Added: 04/15/2019 13:58:08

Lead developer Jack Norris sums it all up in his foreword: the science-fantasy that is Barsoom is one to capture the imagination and hold on to it; and his delight at getting to play in this world shines through these pages. The presentation reaches out to embrace you too, starting with the sweeping red expanses of the end-paper maps. OK, I prefer portrait orientation books but... it's so lush!

So on to Chapter 1: Welcome to Barsoom. If you have so far got through life without visiting, here's your chance to discover what you have missed. It begins with some notes on the author, Edgar Rice Burroughs, and on the science-fantasy planetary romance stories he wrote. Whilst maybe best remembered for having invented Tarzan, John Carter of Mars is a much more rounded character with hidden depths - both in Carter and in the stories themselves - that rise above the whole 'pulp' genre they ostensibly belong to. Noteworthy in this setting: there isn't any 'evil'... just danger and excitement, people with differing objectives, dangerous animals and so on to contend with. There's a brief glossary covering common terms and then we turn to the pragmatic: what you need to play the game and what this role-playing is all about anyway. The three different eras in which you can play are outlined briefly, too.

Next is Section 1, which contains a couple of chapters that take you through creating a character. If you are already familiar with the Modiphius house system, 2d20 or 'Momentum', it's all pretty easy, but even if it is completely newto you, everything is explained clearly. The idea is to create wholly-original characters, but if you want to play the ones from the books, they are presented later on. Characters are created using a nine-step process, beginning with the grand concept of who that character actually is, the undelying basic concept that makes them tick. Next give them some attributes which, unlike many games, are abstract and rather results-orientated rather than specifying physical and mental capabilities. So we have Cunning, Daring, Empathy, Might, Passion, and Reason. Next you choose race: there are several different Martian races as well as Earth humans (who are very unusual) to pick from. Each Martian race is defined by colour, they are fairly homogeneous and serve to provide basic background knowledge and skills. That sorted, you need an Archetype - this is basically what the character does for a living (or did) and allows for a lot of customisation. Each one provides suggestions as to what the character knows and can do; and one or more appropriate Talents are suggested for them. There are all manner of Archetypes: assassins, mercenaries, explorers, envoys, healers, rogues... and if none suits there are notes about creating your own. An interesting feature of this system is that you don't have 'skills' - competency is assumed in the things you know how to do. Now the fun starts. You need a Descriptor. Characters in this game are larger-than-life, dramatic personalities and you pick a word that describes how they approach life - bold, perhaps reckless, courageous or dashing... This has a mechanical effect, in terms of bonuses to appropriate attributes. This is followed by choosing Talents, starting renown and equipment, and a flaw. Finally, you'll need a name, and there are suggestions for how different races assign names.

To aid you, there's a detailed walkthrough of character generation following the description of it, and then some sample characters. Each is presented in quite generic, yet detailed terms. If you're in a hurry, all you need do is slap a name and a few background details on and you could play a 'Stalwart Red Martian Duelist' or a 'Thoughtful Green Martian Guide' or whichever takes your fancy. A separate chapter covers Talents, going into quite a lot of detail as they are pivotal to how a character works. Talents are more than skills or learned abilities. In a game where hypercompetency is assumed, if your background suggests that you can do a thing - or someone has taught you how - you can do that thing... even if it is as complex as flying an airship. Talents are the things that make the character stand out, they can not only do that thing, but do it with style and better than most anyone else. Mechanically, you bring a Talent into play when attempting an action for which that Talent is appropriate.

OK, now you've got a character. Section 2 covers all you need to know to play them to best effect, beginning with Chapter 4: Adventuring in Barsoom, a chapter which explains the basic rules for playing the game. It explains the custom Combat Dice (and how to use a regular d6 if you don't happen to have the special ones), and how task resolution works. It sounds more complex than it is, so try out a few rolls in advance of the game to get the hang of it all. Note that this is for both Narrators and players, and includes all the behind the scenes calculations the Narrator has to do in setting difficulty, etc. It covers Momentum and Threat as well, specialist mechanics that allow player-characters to capitalise on their success - and the Narrator to make things more 'interesting' for them. There is also detailed information on Action Scenes - typically combat - when turn-by-turn tactical play is required. It ends with Damage and Recovery, and Luck. Luck reflects the fact that the Player-Characters are a cut above ordinary people, and gives them a small mechanical advantage - points to spend on die rolls or to influence the story. They are earned back by good role-play.

Next comes Chapter 5: Weapons, Technology and Equipment. There's a selection of weapons, a description of the appearance and significance of the traditional Martian 'harness' (they hate clothes, apparently), and a range of equipment for various purposes. In line with the heroic style, it's generally assumed that a character has whatever they need, unless its absence is part of the plot. The technology chiefly covers the forms of transport unique to Barsoom, but also covers biological science. The last chapter in this section is Chapter 6: Growing your Legend which covers experience, character development and the acquisition of Renown. This is the measure of a character's social and political position, their fame in the community, something vitally important and which can be used to gain accolades or titles.

We then move on to the setting, Barsoom itself, in Section 3, with chapters covering the history of Barsoom and looking at the societies of the various colours of Martian. There's a heady mix of biology, geography and everyday life - religion, social behaviour, warrior customs, slavery, clothing, food and drink (sadly it sounds rather dull), and more. Entertainment, crime, technology, architechture, it's all there. A note is added that the game background reflects that of the Burrough's stories, with things like slavery and gender-designated roles which some modern players may find objectionable. They can always make changes to suit their sensibilities. A chapter on The Green Hordes covers the most common species of Martian, the Green Martians, then The Red Kingdoms does the same for Red Martians (including loads of detail about their cities) and the next chapter in this section looks at the rest of the planet, primarily the northern ice cap, which is a lot more lively than you might think. Finally, the rest of the Solar System is covered in Beyond Barsoom.

Section 5 is Narrator territory, with advice on running the game, a bestiary, a chapter on the secrets of Barsoom and a collection of Champions of Barsoom (this is where you look if you want to play John Carter or Dejah Thoris themselves), loads of interesting and powerful folk for the party to meet and interact with. The advice is sound, much of it applicable to GMing any game, and other bits appropriate to this game in particular (or at least, the sort of sweeping science-fantasy feel this game aims to achieve). There are snippets about using the game mechanics to best effect, and ways to utilise the style of the original stories and their conventions in your game... and how to expand upon the 'known world' in a fitting manner.

The creatures in the bestiary all come with descriptions and even plot seeds involving them, and many are illustrated. There are notes for designing your own beasties too. I'll not talk about the Secrets of Barsoom here: suffice to say there are a good few plot ideas therein! Strange places to explore, too. Chapter 16: Mind Merchants of Mars is a full-blown introductory adventure which opens with the party fighting in an arena as slaves - they'll get a chance to find out how they got there after the fight is over! Then they will probably start to plot their escape... but of course, nothing is plain sailing. Assuming they survive, the next chapter is jam-packed with ideas for further adventures. Plenty there to fill many a gaming session with adventure.

This game captures the epic, planetary romance feel of the original stories well. If you enjoyed them, you will relish the chance to live in Barsoom yourself. If you've never read them, there's sufficient here to get you going (and probably inspire you to track the books down as well). Definately a fun addition to your game collection, perfect for when you need a well-constructed, exciting yet light-hearted game.

[5 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by Larry B. [Verified Purchaser]
Date Added: 04/14/2019 17:40:28

Original review at

Based on the Modiphius 2d20 rule system, John Carter of Mars is a pulp, science romance based upon the Edgar Rice Burrough's series of book. Most younger generations will probably know this better from the Disney movie that was released a few years ago. Long before that poorly welcomed movie, John Carter was one of the early pulp heroes. As a fan of the pulp action era, I was excited to get the opportunity to examine and review this product.

Upon receiving the copy (pdf), I quickly opened the file and flipped through. That doesn't sound nearly as heavenly as the old days of cracking open a new book and riffling through the pages to get the new book smell. It was still a lovely book. It is orientated to the landscape format. I found this a little disconcerting at first. I adapted to it as I continued to read and reread the book.

No Barsoom material would be credible if it wasn't accompanied by good artwork. There is a mix of quality on the art in the book. Some of the pieces are reminiscent of the memorable style of Boris Vallejo. Others are more simplified in quality. All evoke the strange world of Mars (or Barsoom as Burrough's inhabitants of the red planet have named it). The character sheets are exceptionally beautiful. The included map (sadly in 4 pieces divided between front and back in the core rulebook) is also a lovely rendition of the planet.

The modified 2d20 system was new to me. The game requires the use of 20 sided and 6 sided dice. Using attributes of the player's character, you roll to achieve a success below the target number. This may be a little foreign to those who are accustomed to the Dungeons and Dragons system that makes higher numbers a success.

The system allows for more player input to action and outcomes. Turns are not limited to a simple time frame, but allow ample opportunity for the thing all role-playing gamers are famous for: vamping. You can say as much as you like during your turn. There is no more vague concept of acting in a nebulous understanding of time. This is simply your turn. And the narrator is just that, the one who narrates the setting and activity. Of course the narrator still must control the other characters in the game, but players have a lot of flexibility in how their behavior effects the environment or things acted upon. I love that aspect.

I felt that the game is a hybrid of traditional d20 format games and narrative style games, such as Fate. For me, it is seems to be a happy compromise.

The area I felt least competent in speaking to was the content of the world. I have read the first in the Mars books. I saw the movie. I am far from knowledgeable about the world, its main characters, or its overarching story. I contacted a friend who was more knowledgeable about the books (but less competent in the gaming arena). After our conversation, I feel that this represents the world of Barsoom quite adequately. Newcomers to the world may need a little catching up, but it wouldn't be too overwhelming for a new player to be dropped into a game.

One feature that may be a little unclear is which time frame is best played. This is really open to the narrator or the players comfort level. As a neophyte to Barsoom stories, I would default to the earliest represented era. There are three to choose from. The latest era, representing the later books, is considered the "modern" era. There are adequate side-notes to point out playstyle differences between the three.

I found a few typographical errors and print-type errors. Those could be artifacts in my pdf file, though. Overall, the quality of the images in my copy were expert level. I own a number of Modiphius products, and the quality is equal to those.

I am looking forward to expanding my John Carter collection with narrator screen and player resources. It may not be a familiar setting to some, but it is a rich fantasy world with a lot of potential for those who are willing to give it a try.

[4 of 5 Stars!]
John Carter of Mars Core Rulebook
Publisher: Modiphius
by A customer [Verified Purchaser]
Date Added: 04/14/2019 17:25:48
In the past I have bought and played in the Conan RPG and the Star Trek RPG from Modiphius so I was already familiar with 2D20 game engine used in this game. First the artwork in this book is excellent and brings the setting to life The color map of Barsoom is stunning and helpful in playing the game. The player charcter sheets look more like art than a charcter sheet. The player sheet is easy to fill out and use The artwork is also helpful in showing players what the peoples and creatures of Barsoom look like as some people are not familiar these books. The oragization of the book is logical and very helpful in creating a player charcter. I like the fact how Modiphius has contiued to adapt the 2D20 engine to fit each of the games individually. The gamemaster section is very helpful. If you have never read the John Carter of Mars books this will help you a great deal. One strength of Modiphius corebooks, including this one, is the amount of explanations and rules examples they give you. The book also covers the three eras of the book series well enabling a group to play a long campaign while staying true to the books if you like. Information on the other planets and moons of our star system is given and how you can use those locations in your campaign. Suggestions from other books, movies, etc are given to aid in creating your own adventures. They also include write ups for the major charcters from the books and tips on how to use or play them from each era. Using a landscape format for the book is an interesting choice. The artwork is further enhanced by this choice. However when I tried to read it as a PDF it was a bit difficult to do so. Being in a landscape format makes printing any page for use difficult to use in a standard game master screen.

Modiphius has done an excellent job of adapting the John Carter of Mars and well worth the price.

[5 of 5 Stars!]
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