First things first, hello you there my dear reader! Hope you're having a good day.

You'll have to excuse me, but I'm not an english-native speaker so please ignore my inevitable spelling mistakes.

I'm toying with a very specific dice system (to couple with the rough combat system you could find here) and I want to know if it does exist already or if it's similar to other ones you are aware of. I'm looking for specific recommendations and suggestions.

Roll-Under Attributes

In my system, Character attributes are partially free-form and partially fixed. Except from the basic three (Tough, Swift, Clever), each player can write down free-form Elemental attributes, such as Fire or Sound, if their value is above 0.

For example, a character may have the following attributes: Tough 3, Swift 0, Clever 1, Water 2. Narratively, since the character has Water 2, they're able to spit/manipulate/bend water in some way shape or form.

Naturally, since their elemental attributes are missing for other stats, they can't manipulate any other element.

Dice Pool and Successes

The Dice Pool size is fixed to three d6s (but this is just a proof-of-concept and I haven't run it with anydice already). Whenever a roll is required, according to the approach -in Fate Accellerated terms- taken by the character, they roll 3d6 and count the number of dice that came out being equal to or lesser than that stat, and those are successes. The higher the stat, the easier for them to be successes.

The system take into consideration Fictional Positioning with a mechanical angle, by considering both Efficacy (as in "how well you may succeed") and Difficulty (as in "odds of succeeding"); by turning knobs on efficacy, you may reduce or increase the number of successes after the roll automatically by 1, by turning knobs on difficulty, you may reduce or increase the dice pool size by 1. If something is below "easy" is said to be "trivial", no roll is required; if something is above "difficult", it's said to be "impossible" and you can't do it unless you do something in advance to improve your odds.

Keeping the same example as before, that Water-based character tries to put down a vast fire by pouring a water wave over it, but the fire covers half a forest already. This will be a Difficult but Effective course of action, so the player rolls a dice pool decreased by one, count the number of dice equal or lesser to their Water attribute and then add 1 because the approach was considered effective.

Successes will be spent 1-to-1 to succeed on the test or to get additional effects/flares (this relate to specific powers/skills/situations), similar to how holds do work in many PbtA games. I aim to have, for each roll, an average of 1 success and 0/2 successes not all that uncommon (unless you tested for a very low or very high attribute) and - very rarely - even 3 or more, so I'm going to toy around with the pool size to find a spot I'm confortable with.

TL;DR

It's a dice system with a fixed d6 dice pool size, where you count successes for each dice rolled equal to or under the chosen attribute, going from 0 up to 3/4 and (theoretically) 6. Adequate fictional positioning (explained as efficacy and difficulty) may alter the dice pool and the number of successes.

Considerations and Questions

I wanted to switch from a PbtA system with partial successes to a system where you still have degrees of success (here by gaining different successes) while keeping the original low-numbers low-arithmetics crunch, so a dice pool system seems a good fit.

Now, I'm wondering...

• Is it clear as written?
• Did you read something or exactly like this already? I don't doubt for it to exist already, but I never saw it myself.

• Do you happen to have a suggestion on how to write down this on https://anydice.com/ or do you have an explicit formula to adjudicate the odds of getting exactly #n successes, by having an attribute at #m and rolling #p d6s dice?

  Again, thanks for reading and for any incoming suggestions!