Making Critical Fails Fair with 15XX’s Dice Pool Mechanic

I am deep into the editing and revisioning work on 15XX as I get ready for Playtest 04 (sign up for the closed playtesting here!). I hate the page-by-page editing. I’m a big idea guy, and find work that requires a close attention to details toilsome to get through.

But revising rules based on feedback? Figuring out big ways the game can work better and be more fun? Well, that’s not so bad. Here’s an peek behind the curtain into the game’s mechanics, my design process, and an area I could use some outside eyeballs in figuring out.


A classic problem with many dice pool systems I’ve seen is making crit fails, fumbles, or botches fair (i.e. not penalize players rolling lots of dice with an increased chance of a crit fail). I may want to solve this with 15XX in order to streamline and unify another part of the rules.

Design Context

  • My core mechanic has been a straightforward pass/fail
  • There are other places in the rules using “roll dice and check results” mechanic (usually when something really bad might happen)
  • The “roll and check” is usually a second roll the player needs to make after a failure
  • My thought was that I could introduce a botch / crit fail mechanic to combine the two
  • The goal would be to streamline and unify the mechanics

Current Mechanic

  • 1-4 dice d10 pool (determined at the warband level). ​
  • Roll low* equal to or below Target Number X (usually 3-5, determined at the unit level).
  • Only need 1 succeed on any die.
  • I am not counting successes in this system.

Feedback Request on my Potential Botch Rule

These ideas aren’t fully vetted or something I’m committed to. Will appreciate your input:

  • A Botch occurs when the player fails and at least one of their dice results is equal to or higher than a secondary, static TN (I’ll call Y).
  • Similar as PbtA, but with a shifting TN for success: 1-X: Success, X-Y: Failure, Y-10: Botch
  • The Potential Problem: As I roughly understand, the more dice get rolled, the more likely both success and a botch become, thus penalizing player who are able to roll more dice.

Is the obvious fix here that a Botch occurs if ALL dice results are equal to or over Y?


Potential Alternatives

  1. Keep the “Roll and Check” system in place: It’s functional, but feels clunky and unoptimized. I’d like to be able to combine things if a workable solution could be found.
  2. Remove the dice pool; make the core mechanic a d10/20 roll under X+Y: This would make it easy to get the PbtA split. Add your Warband-level stat and Unit-level stat together for your Target Number, then roll a single die. I like that I don’t have any addition or subtraction built into the basic core mechanic, and would like to keep it this way. Also, my current buff/bonus mechanism is built into the dice pool. I don’t want to move into being another 5E Advantage/Disadvantage copycat, but the other obvious option is adding a third set of numbers to add to your TN calculation, which I’m not an fan of on first glance.

So there it is. Would appreciate some extra eyeballs on this one!

One comment

  1. The dice pool mechanic sounds interesting. And I think there could be a middle way between a botch occurring with just one die equal to or above Y and a botch occurring only with all dice equal to or above Y: an alternative could be that at least half the dice results (rounded up) must be equal to or above Y for a botch to happen. Thus, 1-2 dice = 1x Y is botched, 3-4 dice botch on 2x Y, 5-6 dice on 3x Y and so forth. This way, the probability of a botch would always be within a similar range, regardless of the size of the dice pool.

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