Knaves of the Ninth World: A Numenera conversion

Featured image artwork is TM and © 2019 Monte Cook Games, LLC.

I’ve been kicking around ideas for a far-future adventure and exploration game lately, along the lines of Numenera and In the Light of a Ghost Star. In the process, I stumbled upon the realization that Numenera content maps surprisingly neatly onto the rules for Knave. Since I apparently can’t stop hacking Numenera, I figure I might as well get it out of my system one more time (and then maybe get back to working on my own game).

Character Creation

(Optionally) determine descriptor, type, and focus—”I’m a [descriptor] [type] who [focuses]”—either randomly, or, if you’re up for some pretty in-depth character creation, by sifting and choosing from the Numenera core rules or more recent Numenera Discovery edition. Ignore pretty much all the game mechanics related to these things, except for the following:

  • Descriptor will affect how you roleplay, and if it feels relevant to a roll, the player can suggest that it might grant an advantage.
  • Glaive (warrior) type characters can wear any armor, use any weapons, and carry 2 cyphers at a time. They get combat maneuvers when they advance.
  • Nano (mage) type characters can only wear the lightest armor (up to gambeson, in Knave terms), carry only the lightest weapons (one-handed weapons that do d6 damage), and carry 3 cyphers at a time. They get the high-tech equivalent of magic spells when they advance.
  • Jack (rogue) type characters can wear medium armor (up to chainmail, in Knave terms), use medium-sized weapons (one-handed weapons that do d8 damage), and carry 2 cyphers at a time. They get lesser versions of the above options when they advance (plus some more options if you have Numenera Discovery … or more open-ended skills if you use variant rules suggested below).
  • Focus will be what really sets your character apart, so everybody should choose a different one.

(Alternatively) agree to play as “explorer” types using the classless Knave rules. You can still choose a descriptor (or “Virtue” or “Vice” trait from Knave), type (or “Background” trait from Knave), and focus. Either these have no mechanical effect (again, like traits in Knave), or (like Descriptors as noted above) they may grant an advantage on relevant rolls. If you’re feeling especially daring, you can mix and match, like:

  • Descriptor (from Numenera) is only for roleplaying purposes.
  • Background (from Knave traits) grants advantage on relevant rolls.
  • Focus (from Numenera) offers a special ability each level for levels 1–6, because the GM of this particular game really loves converting things and/or on-the-fly rulings. (Consider some examples here, converted to Into the Odd.)

Determine ability bonuses by rolling 3d6 three times for your Might, Speed, and Intellect, taking the lowest die from each. You may swap two results. If your group isn’t fond of random character creation, set one ability at +3, one at +2, and one at +1; you can subtract 1 from the +2 or the +3 to add to another score. Abilities can be raised as high as +10 during play. (You can also use the standard six D&D attributes without breaking anything, though there’s obviously nothing in any Numenera adventures that will call for them to be used.)

Determine hit points by rolling a d8, or just take 4. If you want characters who will survive much longer (which is likely the case if you want to use more in-depth character creation and get attached before you even play), also add the sum of all your abilities (+6).

Item slots are optional in this hack, as far as I’m concerned, but if you want them, I’d advise going with Might + 10.

Starting items can be generated randomly for “explorers,” but should be chosen more purposely for traditional types. Consider giving glaives any weapon or armor they want, jacks medium weapons and armor, and nanos a light weapon and light armor, plus random cyphers, a random tool, and a random oddity for each character.


Track experience points using either Knave’s rules, Numenera’s rules, or something else. If you use Numenera’s rules, I leave it to you whether you also want to use its alternative XP options, like gaining from “GM intrusions” and spending on temporary benefits. (I’m pretty sure you could skip them all and the game would still function just fine.)

Choose advancement options when you gain a level (or “tier,” as Numenera calls them).

  • HP increases by d8 (or by 4).
  • Add +1 to an ability of your choice.
  • Gain a special ability from your type of your tier or lower, randomly or by sifting through the Numenera core book. See “Special Abilities,” below, for conversion tips.
  • Gain a special ability from your focus matching your tier (or the tier you’re working toward if you already have that one) from the Numenera core book. See “Special Abilities,” below, for conversion tips.

Alternatively, if playing as classless “explorers,” or if you don’t want to sift through so many advancement options, replace both special ability gains above with:

  • Glaives gain a new combat maneuver. This acts like a stunt in Knave rules, but you can use one such maneuver every round, in conjunction with an attack or defense roll (like pushing with an attack roll or disarming with a defense roll), without having to give up advantage on your roll.
  • Nanos gain a random spell from Knave’s “100 level-less spells.” Change the flavor a bit as needed, and call it an “esotery” you discovered. You can cast it once a day.
  • Jacks gain a new non-combat skill. They roll with advantage whenever using a skill.
  • Explorers can choose any one of the above when they gain a level. Or they get none of the above, if the GM and players want to keep things simple. That’s okay too!

Cypher capacity also increases by 1 when you reach levels 3 and 5.

Special Abilities

If you are playing as classless “explorers,” or using the alternative advancement rules above, you can skip this section.

Converting special abilities can be labor intensive, so I advise the GM to make rulings for how they should work as players choose them, and just make sure everybody is on the same page about how they should work. (My conversion to Into the Odd might be helpful; I converted a bunch of specific foci and esoteries to that system.) In general, I’d advise….

  • Anything that would restore points to a pool restores HP.
  • An attack that does 1–2 damage does d6 damage; anything that does 3–4 damage does d8 damage; anything that does 5–6 damage does d10 damage; anything that does more does d12 damage.
  • A bonus to damage might just add to damage or increase a damage die one size (if you’re open to that level of fiddly rules), or might just grant advantage on damage rolls.
  • A bonus that improves rolling odds might just add to the roll if you’re open to that level of fiddly rules, or might just grant advantage otherwise.
  • Anything that ignores any armour ignores all armour; roll against an armor defense of 11.

Using special abilities could be handled a few different ways.

  • Once a day, like casting spells in Knave.
  • Using the stamina rules from Grave—the less gear you lug around, them ore you can use special abilities. Abilities cost as many stamina as their tier minus 1.
  • PCs get as many “talent points” as their level. Again, abilities cost as many points as their tier minus 1.


Here’s how you take a creature from the Numenera rules and make it work in Knave.

Hit dice are based on a creature’s difficulty level. A level 5 creature, for instance, has 5d8 (or 20) HP. (This might break down for very high level creatures, like the level 10 organic space ship that can annihilate an area with missiles from miles away, so use your best judgment. Consider adding 50–100% of level to HD for anything that sounds like it deserves it.)

Armor defense is 10 + creature level + armor score from Numenera.

Attack bonus is equal to the creature’s level.

Damage could be calculated as above (1–2 is a d6, etc.), or for quick conversion you don’t have to think about, use a die with twice as many sides as whatever number is shown in Numenera.

Morale is based on the creature’s level (if you are feeling lazy) or 5 + half level, rounded down (if you want a more traditional 5–9ish range).

Rolling the Dice

Saving throws, as in Knave, are rolls you make when the outcome of an action is uncertain and failure would have consequences. By default, the goal is to roll a d20, add the most relevant attribute, and hope to get over 15. If you want to use the varied difficulty of different challenges presented in Numenera materials, roll over 10 + the level of a challenge (i.e., over 11 on a level 1 challenge, up to over 20 on a level 10).

Attacking works similarly. Roll a d20, add Might (for any melee attack) or Speed (for ranged attacks, and, optionally, for melee attacks with light weapons), and hope to get over 10 + the target’s level. If using enemies from Numenera materials, if it says, “Defends as [some other level],” then use that level. If you hit, roll damage, and subtract the result from HP.

Defending works just the same too. Either monsters can attack PCs and add their level as an attack bonus to a d20 roll, trying to get over the PC’s armor defense (13 for light, 15 for medium, 17 for heavy), or players can roll a d20 and add their armor bonus (+3 for light, +5 for medium, +7 for heavy), trying to get over 10 + the monster’s level.

Advantage and critical hit rules are unchanged from Knave.

Final Notes

It’s worth noting that Knave is a complete game on its own, and could be used without any rules modification and only light “reskinning” to play in a far-future setting. These conversion notes are primarily for those who have a bunch of Numenera books and want to get some use out of them with a more lightweight rule set.

In case it’s not obvious from how frequently I offer hypothetical, optional rules, these conversion notes have not been tested at all. If you give these rules a try, please leave a comment, let me know on Twitter, or say hello to JasonT on the Knave’s Inn Discord.

This is a fan work only and not officially endorsed by Monte Cook Games. Featured image art is TM and © 2019 Monte Cook Games, LLC, used under the Monte Cook Games Fan Use Policy.

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