I changed my Dice System 5 times this week

[Devlog #2]

Matt Colville says the most important thing you can do when designing a game is know what your game is about. Not what it does. What it's ABOUT. He uses design keywords. Four words that every mechanical decision gets measured against. If a mechanic doesn't serve one of those words it gets cut.

My keywords are Cinematic, Resourceful, Expressive, Modular, (and im thinking of adding LIGHT into the mix)

Today I tried to find the dice system that serves all four and my intentions.

Let me walk you through my thought train.

First thing I decided before looking at any specific dice: I want a tier system, not a difficulty check. Comparing your roll against a DC that changes per situation is extra cognitive load that breaks narrative flow. You roll, you look at your result, the tier tells you what happened. Same thresholds every single time. No asking the GM "wait what was the difficulty again?" PbtA figured this out twenty years ago with their 6-/7-9/10+ bands and every system that uses it plays faster at the table.

But I didnt want three tiers. I wanted five.

Three tiers gives you fail, partial, success. Thats good. But it misses the extremes. The absolute disaster that becomes a story people tell for years and the moment of impossible brilliance that makes the whole table lose their minds. D&D gets this with the nat 1 and the nat 20. Those moments are part of what makes rolling dice feel alive. A three tier system treats all failures the same and all successes the same, and that flattens the emotional range of the dice. Now i know there are options around this like rolling 2 6's and counting that as a success and there are probably more options. But it just never felt like that nat 20 (that high)

So im going with five tiers: critical failure, failure, partial success, success, critical success. Now the extremes have mechanical identity. The worst roll isnt just "you fail." Im thinking lets go with "something catastrophic happens and YOU the player get to narrate what goes wrong." A GM says "the guard disarms you." A player says "my fathers sword, the only thing I have left of him, shatters." That's the kind of moment that makes RPGs transcend the table. and if i can find a way to attach a reward system to it then a critical failure for a player becomes not his shittiy experience but HIS moment to SHINE as a player and progress narratively as a character.

The critical success is the reverse. You dont just achieve your goal. You discover something, you create a new aspect in the scene, something extraordinary happens that exceeds what you attempted. The dice gave you a gift and you get to unwrap it.

Now the dice themselves.

I started with PbtA. 2d6 sum, three tiers. The math is genuinely good. Partial at 42% is the biggest outcome, failure at 42% feeds my invocation engine (a rubber band mechanic where low rolls generate tokens you spend on gear and environment for bonuses), full success at 17% feels earned. Someone on my last devlog called me out for never identifying a real downside to 2d6+mod. They were right. I couldnt find one. It was a gut objection.

But heres the thing. I kept circling back to 2d6 and walking away. And each time I had to be honest with myself about why. Part of it is that it just feels like building another PbtA fork. But the bigger issue is that 2d6 gives fail and partial at identical 41.7% each. A flat plateau. And the range of 2-12 caps your design space for extreme results. A natural 12 on 2d6 happens 2.78% of the time which is fine for rarity but a 12 doesnt FEEL legendary the way a nat 20 does. And a natural 2 happens equally rarely but the number 2 doesnt carry the same emotional weight as a nat 1. someone suggested one issue today in my last post, if i want more room to play with bonuses then the statistics break completely, with +3 then partial success become around 90%. this doesnt leave room if i want more mechanics that could effect the roll.

3d6 sum fixes the plateau with a real bell curve but the success threshold shifts to 14+ and I have learned something about myself. I feel the difference between 9 and 10. I do NOT feel the difference between 13 and 14. Draw Steel uses 2d10 and has this exact problem for me. Numbers that are technically different but dont feel different in my hands. Ruled it out.

Dice pools counting successes. Tested 5d6 count 4+, 5d6 count 5+, 6d6 count 5+. Ran into the binomial plateau problem. With a 50% success threshold and 5 dice, P(exactly 1 success) always equals P(exactly 2 successes). Thats just math being symmetrical and it means the middle tiers are always tied. I tested 10d6 count 4+ in my earlier game and players rolled exactly 5 successes over and over. They hated it. Too consistent.

FitD take-highest. I love the emotional range of pool sizes in Blades in the Dark. 1d feels desperate, 4d feels powerful. i hope id be able to duplicate this feeling. But getting a 6 on a d6 doesnt give me that holy shit feeling. A 6 is just a 6. Maybe thats just me but the number doesnt carry weight.

Step dice from Cortex Prime. Physically seeing competence as a bigger die in your hand is incredible design. But the range expands as dice step up and the fixed threshold breaks. d6+d8 gives 31% full success where base gives 17%. d6+d10 hits 45%. Too generous too fast. If I shift the threshold to compensate then players track both which dice they roll AND what counts as success. Might use step dice inside a framework though.

So what did I actually pick: Xd10 keep highest. Five tiers.

1-2 critical failure. 3-5 failure. 6-8 partial success. 9 success. 10 critical success.

Base roll is 2d10 (considering lowering it to 1d10) keep the highest die. Proficiency adds a die, edge adds two. The thresholds never change. You always just read the highest die.

Base 2d10: critical fail 4%, fail 21%, partial 39%, success 17%, critical 19%. Partial is the clear king at 39%. The game lives in the yes-but zone. Failure is a real possability at 25% combined (crit + fail). And success plus critical combined is 36%, enough that pushing for it feels like a real gamble not a prayer.

Proficiency 3d10: crit fail under 1%, fail 12%, partial 39%, success 22%, critical 27%. Failure drops hard. Partial stays dominant. The character is competent and you can feel it. Critical success at 27% means roughly one in four rolls produces something extraordinary when youre in your element.

Edge 4d10: crit fail basically zero, fail 6%, partial 35%, success 25%, critical 34%. An edge specialist almost never fails. Partial is STILL the biggest single outcome at 35%. But critical success is nipping at its heels. A master produces brilliance regularly but not automatically. There is always tension.

Why d10 specifically? Because a 10 FEELS like something. Rolling a 10 on a d10 has weight that a 6 on a d6 doesnt.When that 10 lands face up the table reacts. Thats the nat 20 energy I wanted. And a 1 on a d10 has that same gut punch as a nat 1. The numbers carry emotional strength.

Why keep highest instead of sum? Speed. You roll your pool, you find the big one, done.

The invocation engine also adapts cleanly. After your roll you get invocation tokens based on the gap between your result and the success threshold. Low rolls generate more tokens. You spend tokens to invoke gear, environmental aspects, enemy weaknesses for +1 each which can make a failed roll into a success BUT at the players creativity. they have to find the aspects/ gear/ anything possible to invoke to get a bonus.

Now heres the part I havent fully tested yet but im excited about.

Every action, the player faces 2 choices.
Settle: accept the default outcome without rolling. If you have leverage in the scene you can invoke aspects to push the settled result from failure up toward partial. But you can never reach success without rolling.
Roll: spend effort (a limited resource? still concidering) to actually throw the dice. This is the only path to success and critical success but it also exposes you to critical failure.

Settle or roll.

What this means is that rolling dice is never mandatory and always meaningful. A cautious player can navigate an entire scene through settling and invoking, accepting complications and using their environment. An aggressive player burns effort and chases critical results. A tactical player reads the scene and knows exactly when the gamble is worth it.

This maps directly to the three player types I see at my table. The optimizer who stacks bonuses and invokes perfectly. The action player who describes a five+ part cinematic attack and rolls once for an action scene that normally would take 5 turns of dnd. The storyteller who takes the complication on purpose because it makes a better scene. All three are mechanically supported. All three are (or at least should be) rewarded through different paths that feed the same engine.

That's where I am. The effort economy needs playtesting. The invocation math needs tuning. But the dice feel right for the first time for me.

If you've played systems that use d10 pools I want to hear how they felt at the table. If youve tried a mechanic where rolling is optional and costs a resource I especially want to hear what happened. And if you think I missed something and have a flaw I haven't seen yet please tell me.

that's my raw thoughts, for clarification im not saying that the dice roll mechanic i came up with is new or even perfect. im just trying to find what feels right to me and be cleaver about it so i make the game i want to play