A misreading of something in Index Card RPG got me thinking about how you might replace d20 resolution with a standard deck of playing cards, if you were so inclined. (I’m guessing most people would not be so inclined, but it was a fun exercise for me when I wrote it up on G+ months back, and I’m still combing through those old posts to edit and repost here on the blog.) It’s a tricky question because playing cards don’t go all the way to 20, and if you draw 2 cards blackjack style, it’s going to skew very high with all the face cards. Options I can think of offhand, though, might include….
Draw 1 high: Cards are equal to numerical value, adding your stat modifier, trying to get over target number. Jacks are equal to 12, queens to 14, kings to 16, aces to 18. Black joker is critical success, red joker is critical failure, and anytime you draw a joker, you shuffle the whole deck again.
Draw 2 and add: Draw 2 cards and take the sum. You could set this up to draw low, on or under an ability score (Black Hack style), or draw high, over a target number (D&D 5e style). I honestly have no idea offhand what face cards should count as in order to make the odds feel right, but I’m guessing they shouldn’t all count as 10+. There’s some funky stuff you could do with suits, colors, faces, and/or proficiency. For instance….
- Proficiency affects card values: If you’re proficient in the action being performed, face cards all count as 0
- Ability modifier affects suit values: Each +1 you have in an ability, you can name one suit that counts as 0
- Color determines card values: the two cards you draw match in color, face cards count as 10, but if the colors don’t match, they count as 0.
- Color determines whether you draw again: Draw 1 card and go by face value, with face cards equal to 10, aces equal to 1. If it’s black, draw and add a second card. This will give more of a pronounced curve than a d20, but I don’t think that’s a bad thing, myself.
Just play blackjack: I’m actually working on a game that uses blackjack for resolution, and something tells me it’s more interesting than trying to approximate something dice already do a great job at. Brainstorming this has been fun, though!
Pretendo Games 
3 responses to “1d52”
I feel that card handling can be fiddlier than dice sometimes, so instead of working so hard to get cards to act like dice (like you say at the end), lean into the potential for player decision during the resolution process. Cards make resource management really easy (having a hand of “rolls” to choose from), and using something like blackjack can bring push your luck mechanics to the forefront.
That is very much my preference. I have tinkered with card-based RPGs a bunch, and I’m pretty much never satisfied with anything that doesn’t let players keep at least one card in hand to throw out at just the right moment. But sometimes I can’t help myself from thinking “how would this work?” about a mechanic I’d be unlikely to actually use. 🙂
Story of my life. 🙂
I can’t quit dice, though. Maybe an asymmetrical setup where the GM rolls dice for stuff but the players have cards, since that could take a bit more management. And literal hands.