Conan conversion?

I got an email about a JCoM / Conan rules conversion PDF but have yet to receive a link to the files on Drive-Thru. I contacted Modiphius suppport and got a ticket on 1/8 but I’ve not heard back yet. Is it just me?

Go to your driveThruRPG account. Every message you receive from them can be found there.

As stated above, there is no link.

I cannot believe this. If you received a message from DriveThru RPG about this book, then there should be a link at the end of it.
So, please go to DriveThruRPG and log into your account. There go to ‘Account’ and then to ‘Notifications inbox’ and open the message titled ‘Free Digital Download from Modiphius at’.This message should look like this:

Free Digital Download from Modiphius at
Chris B. (2020-01-08 04:33:52)

Modiphius has sent you a free downloadable copy of a title on

Hi there,

Please find enclosed your complimentary copy of the John Carter of Mars Conversion guide. Some narrators prefer the rough and tumble 2d20 rules of Conan to the streamlined rules of John Carter of Mars. To make the world of Barsoom come to life for more of the Modiphius fan base these conversion rules have been made to convert characters made using John Carter of Mars to work with the rules of Conan: Adven­tures in a Age Undreamed Of.

Best wishes,

Modiphius Entertainment


When you click the link, the title will be entered into your shopping cart with the price set to zero. Simply click the link below to load up your shopping cart and then check out to get your free title.

John Carter of Mars: John Carter Conversion Guide

The link should be in the last line of the message.

Never received email from drive through. Modiphius support has not gotten back to me since the 8th.

Sounds like a job for Lloyd - support@modiphius!

Speak of the devil and they shall appear!

Not sure what happened on the email side - but I just sent the PDF through to you on the Xoraque email listed on here. Let me know if you got it.

1 Like

Thank you Lloyd

I’ve used the conversion rules on the pregens from the core rules. I think that they are over powered.

Character                         Sum of   Number of skills with level...
                                Attributes   5    4    3    2    1
Courageous Earthborn Explorer       58       7    2    6   10    0
Bold Earthborn Soldier              57       9    8    0    4    4
Canny Red Martian Envoy             61       6    9   10    0    0
Stawart Red Martian Duelist         59       7    7    7    4    0
Charming Okar Spy                   60       8    9    0    8    0
Driven First Born Airship Officer   57       0   14    9    2    0
Thoughtful Green Martian Guide      58       6   10    0    5    2

According to this the characters are after the conversion underpowered in their attributes but overpowered in their skills.

I’ve tried to convert an NPC from Conan to John Carter using the Conversion Rules.
Seven lieanr equations with 6 unknowns shouldn’t be a problem. Except when Awareness and Coordination are NOT identical, because in this case the whole system of equations in unsolvable.
One Example:
Siobhan (Conan pp.404-405) has following attribute scores in Conan:
Awareness 10
Intelligence 9
Personality 9
Willpower 9
Agility 11
Brawn 8
Coordination 10

Using the conversion rules and always using the highest equalent John Carter attribute combination score for each Conan attribute score, gives us following attribut scores:
Cunning 9
Daring 9
Empathy 7
Might 4
Passion 7
Reason 7

But if I try the same for Bêlit (Aw 10, In 9, Pe 13, Wi 9, Ag 12, Br 7, Co 12; Conan p.354), I get impossible attribute scores:
Cunning 15 !
Daring 5
Empathy 11
Might -2 !
Passion 11
Reason 3

I’ve forgotten to add the equations so that others can use them for their own conversion of Conan characters to John Carter.
Cunning = Awareness/2 + Coordination/2 - Intelligence/2 + Personality/2 - Willpower/2
Daring = Agility - Awareness/2 - Coordination/2 + Intelligence/2 - Personality/2 + Willpower/2
Empathy = Intelligence/2 + Personality/2 - Willpower/2
Might = Brawn + Intelligence/2 - Personality/2 - Willpower/2
Passion = Intelligence/2 + Personality/2 + Willpower/2
Reason = Intelligence/2 - Personality/2 + Willpower/2

Important: Always convert the Conan attribute scores to John Carter attribute combination scores before entering them into the equations!
Some characters cannot be converted (see Bêlit above).

1 Like

There is a much more easier way to convert Conan characters to John Carter, by using the Skill Bonus Table.

  1. Write down the six John Carter attributes
  2. For each Conan skill compare its skill bonus with the Skill Bonus Table
  3. Write down the value given in the table below both John Carter attributes
  4. The highest number written under each John Carter attribute is the final value of that attribute.
  5. If the sum of John Carter attributes is less than 36, then increase the highest or lowest attribute by 1. Repeat this until the total is 36.
  6. In the end no attribute must have a value below 3 or above 12.

"Seven lieanr equations with 6 unknowns shouldn’t be a problem. "

Actually it would be overdetermined, so there is generally no exact solution, and linear equations don’t respect the boundaries of the attributes, either, as you noticed with Bêlit. :thinking:

Regardless, how can I get these conversion guides? I would very much like to run Conan using a lighter system than the default. JCA seems like it would fit the bill fairly well. From poking around it seems this was a Kickstarter-only thing, but of course that’s long since over—I bought my copy from my FLGS.

Forget them. They are completely broken.

I’ve converted one of the pregens from the John Carter CRB to Conan and waht did I get. Two skills at 5, all other skills at 2, and every attribute at 12 or higher!

See this topic for the problems I have found:

I know. And that’s the reason I now use an easier method. See post #11.
But even this method is not without problems, because one Conan skill of 5 will lead to two John Carter attributes of 8. Thus Conan himself would have a score of 8 in every attribute.

Conan the King has complete stats for Conan so I used them to convert him according to the rules I’ve written down in post #11.

Conan the King
Cunning: 8
Daring: 8
Empathy: 8
Might: 7
Passion: 7
Reason: 7

Confusion: 8
Fear: 8
Injury: 8