Modular dice pool resolution

10 Apr, 2026

Objective

• Player-facing rolls that cover a lot of ground.
• A mechanic that scales relatively well without involving a lot of math.
• Sexy bell curves.
• Modularity: nuance when needed, speed otherwise.
• Incorporating some sort of game-like quality that calls for interesting choices.

Introducing: Unnamed Dice Pool Procedure - version 1

Stage One: The Humble Dice Pool

Skip to Stage Two if you already know why you won't roll 10 sixes on a 10d6 pool.

A simple roll for simple problems. How fast can you run? How much can you lift?

1. Agree on which score is being tested.
2. Pick a corresponding number of six sided dice.
3. Roll the dice.
4. Count all the dice that rolled a 6. Those are your successes.

Easy to math? check.

Don't mind the fact that there's no game attached to it yet. Just imagine scores in the range 1 to 10, with 3 being a nice starting point. The chart below shows how getting at least 1 success (one a six) increases with the size of the dice pool.

Sexy curves? check.

The probability of getting at least one success starts at around 17% for 1d6. It shoots up pretty rapidly at first, hitting 42% at 3d6, then the increments become gradually smaller and smaller. It ends at 84% on a full 10d6 pool.

This is a positive if you don't want your chance of total failure (zero successes) to completely disappear at high levels. In our maxed out 10d6 dice pool, the chance of getting 0 successes is still about a 1-in-6.

Considering the maximum number of total successes we should expect however, the dynamic isn't exactly intuitive. The next two charts compare the probability curves of successes in 6d6 and 10d6.

The increase from 6d6 to 10d6 doesn't look that dramatic, does it? Out of those last 4 score increases we're basically just halving the chance of a total failure, and increasing the chance of 4 successes from 0.8% to around 5% (like a nat. 20). Sure, the chances to get 2 or 3 successes almost double but it still feels lackluster.

This is known property of dice pools that I won't delve too deep into. There's plenty of articles explaining how this happens. Let's just say that almost no one, at first glance, expects the probability of rolling 10 sixes on 10d6 to be about 1 in 60 millions, which according to Google is 6 times less likely than getting struck by lightning twice.

Also, at this stage there isn't much of a game attached to it (apart from the rest of the RPG that hopefully is, or will be there). There is no choice to make: rolling more dice is better, even if the benefit appears negligible.

Stage Two: Skillful Dice Pool

Let's now introduce a second variable to play with in the form of a skill score. This isn't a brand new concept per se, just as dice pools themselves, but I haven't seen many instances of skills being used in the same way:

1. Agree on which base score is being tested (e.g. Strength).
2. Agree on which skill score better applies to the task (e.g. Martial Arts).
3. Pick a number of six sided dice equal to the base score.
4. Roll the dice.
5. For every point of skill, increase by 1 the result of a single die (up to its maximum of 6).
6. Count sixes. Those are your successes.

As established in the previous chapter, increasing the dice pool size starts making little sense after a while, so we're not doing that. Instead we use our skill score to cheat!

Imagine you rolled a 4d6 dice pool and got 5,5,2,1. That's a big Awwww, snap! moment isn't it? ...But wait! You have a few skill points to spend and suddenly those two fives become two sixes! Success!

Ok that felt good, but how much do we really get out of the extra time spent selecting skills and assigning those bonus points after a roll?

The following chart assumes the skill points are always spent on the dice that make most sense. Which means starting with the ones that rolled fives, then fours, etc, until all skill points are spent.

Sexy curves? Double check!

Not bad huh? Imagine you spent your XP on 4 skill points instead of 4 more base score points. Your chance of rolling 4 successes would be around 20% instead of 5%. Even better, going for 4 skill points on top of your 6d6 makes the chance of rolling no successes practically null.

Easy to math? That's less than a check now. But still pretty easy... 2/3 check?

Now some might argue that in principle this isn't so different than lowering the success threshold from six to five or a lower number. And they'd be almost correct. An adjustment of 1 step in the threshold for success, let's say from six to five, produces a huge change in the probability curve. And, unless one wants to spend time juggling an extra variable and rolling separate pools, the change would apply to all dice in the pool compounding dramatically with increases in pool size. This method instead scales in much smaller increments without requiring a lot of extra bookkeeping.

Meaningful game-like quality? Not entirely check. But we're getting there.

Granted, there is still an optimal path of progression that maximizes your average number of successes. For a single pair of base score + skill, that is. But your average TTRPG will have more than one base score and one skill to mix and match. So the space for interesting choices is starting to appear. At least when it's time to level up.

Stage Three: Precision Dice Pools

This is were the mechanic from stage two really shines, in my opinion. We can get an extra dimension of success out of the existing procedure. That's right, it generates two separate (but related) results at the cost of one: successes and precision.

1. Agree on which base score is being tested (e.g. Strength).
2. Agree on which skill score better applies to the task (e.g. Martial Arts).
3. Discuss what precision (also control or finesse) would allow in this context (e.g. Called Shot)
4. Pick a number of six sided dice that is lower or equal to the base score.
5. Roll the dice.
6. For every point of skill, increase by 1 the result of a single die (up to its maximum of 6).
7. Count all the dice that show a 6. Those are your successes.
8. Check your lowest scoring die (after skill). That's your precision.

So you end up with a success score, measured in number of successes, and a precision score ranging from 1 (sloppy) to 6 (flawless).

Why? Well, imagine a character isn't just trying to hit an opponent, they're trying to hit their right hand to disarm them. that requires precision. Or maybe they're trying to quickly and quietly snatch the cell key off of a guard's belt. That requires finesse. Intimidating the king in his court without causing a commotion. Requires savior-faire. Etc.

Most systems would suggest you handle these scenarios by simply cranking up the difficulty, often into critical hit territory, which isn't great. In addition that harder roll stays a binary pass/fail affair, which more often than not discourages players from trying anything cleverer than I attack for fear of losing the opportunity to make any progress.

Yes, I hear you. A lot of people have used degree of success for decades with great effect. But there's still no game quality to it, no added decision making. A player just rolls the dice and hopes for the best.

Indulge me for a moment, if you will, and consider the following example:

GM: The guard stops to light their pipe. They're at arms length, but you're still in the shadow behind the column so they don't notice you. You see an iron key and a small pouch dangling from their belt.

Player: Before they move away, I'm going to gently lift both off the belt without making a sound.

GM: That's pretty daring! Let's see... You have to act quickly, without tugging on the belt. You're going to need 2 successes just to lift one item smoothly. The second item will need an additional success. And just so you know, the pouch has coins in it, you'll need a precision of at least 4 to avoid the jingling.

Player: Can I decide what to pick after the roll?

GM: Yes, but all of this happens pretty quickly, so it's one roll. No second chances.

Player: Alright, I can do it. My Dexterity is 6 and I have 5 points in thievery. So...

What would you do?

You could roll up to 6 dice. That's a lot of dice... But then again, is rolling more dice going to help you? Remember, at the end of the scene you don't just need 3 dice to be sixes, you also need your lowest die to be at least a 4 if you want to get everything. What if you roll two ones along your sixes?

Let's say you roll 4 dice. I asked Google to roll 4d6 and it gave me 6,5,3,2 which is a decent roll. What do you do now? You have 5 skill points to spend but that only gets you up to 6,6,6,3. Enough successes to take both key and coin, but not enough precision to get the pouch quietly. ...Or maybe, shifting a point around: 6,6,5,4. That would allow you to get the money without making a sound. If you leave the key...

I'm really tempted to say check!, but I won't. After all this is just a little dice procedure, which hardly makes a game. That, is going to start happening in a later post.