A new dice mechanic concept

So, about a year ago, I had a bolt of insight/inspiration for a new game. It came about after looking at some old D&D 3.5 books and some old 5e D&D play test documents. I'm not a great writer, so I hope I can communicate my ideas.

I'm calling this ACTION DICE (ad) right now. It uses standard gaming dice d4, d6, d8, d10, d12, d20, and it has the potential to use anywhere from 1 to 5 of each type, possibly more for the smaller dice. So you might need a few sets, or share among your table. Play-by-Post is was another factor I was designing for, so sites like Gamers Plane are good too.

So...the system. Each PC starts with 5 action dice that are d6s. Any action you roll for requires at least 1 action die to even attempt it. This is a dice pool looking for a number of successes for each action. A result of 4 or higher is success. Every multiple of 4 is an additional success, so a 4 is one success, 8 is two, 12 is three, 16 is four, 20 is five.

PCs are limited on how many dice they can roll for any given action by their stats. An average human would have a 2 in all stats, and that would be the limit on how many dice they can roll.

The trick is, you can 'merge' your Action Dice to increase the die size and increase your chances of getting enough successes. So if you want to leap across a chasm, and the GM assigns a difficulty of 3, but you only have a 2 in strength, there is no way to succeed on the 2d6 you get normally. But if you merge your dice, you can turn 2d6 into 1d8. You can continue to merge dice...every d6 you add increases the die one step. So 1d8+1d6 is a 1d10. So you could merge all 5d6 action dice into 1d20 if you wanted to. You are still limited to the 2 dice because of your strength.

Now, you probably want to ask "Why not just merge the dice to the maximum every time you try to do something?" And my reply is that you can, but that limits your action economy. As long as you have one AD, you can take an action. So a "first level" character could make 5 attacks if they wanted, but they wouldn't have as high of a rate of success. And you need to actively defend against being attacked. So, jumping across that chasm when no one is trying to kill you, sure, go for broke. But if you have to dodge a knife attack on the other side, you might want to save an Action Die or two.

So, that's the jist of what I want to discuss. Do you think this system works? It's a balance between rolling more dice vs. bigger dice. I'm not a mathematician, but I think statistically, it works. I contemplated removing the limits and just letting players roll whatever number of dice they wanted to, letting the need to roll defense balance the desire to roll a big pile of dice or the biggest size of dice possible.

And, just to briefly touch on it..."leveling up" at this point will give players the ability to either increase their stats or add to their pool of Action Dice, so five is just the beginning.

And another thing...has anyone seen a system like this before? I was inspired by early 5e D&D designs. They rolled it back and now only the Fighter/Battle Master Maneuvers reflect the original ideas they put out. But I haven't read all the games out there. It's also possible I picked this idea up and have forgotten where I saw it originally. I don't know if I'll ever "publish for profit" but I don't want to unknowingly crib from someone else.

Thoughts and input? If you want to run your own "experimental scenes" on this thread, feel free, I'll GM or clarify how I would run the scenarios. If enough people like this idea, I would thinking of running an alpha test game. It would be a magical girl/super sentai story, the base setting I came up with.

Haven't finished yet, but my immediate concern here is stats balance...2d6 averages to 7 while 1d8 averages to 4. However, I understand that merging will be 1d6 + 1d8, which averages to 8ish probably.

I think it sounds like an interesting concept. It'll require more fine-tuning, especially in regards to levelling up, and lots of testing, but it's a cool starting point!

One thing I'm not quite clear on: Do I count the different dice' successes separately and then add them together or do I add the results of the dice together and then determine the number of successes?
(e.g. if I roll 2D6 and my results are 6 and 2, do I:
1) get 1 success (6=1 success, 2=0 successes) or
2) get 2 successes (6+2=8=2 successes?
I wouldn't worry about that too much. Every idea comes from somewhere.
Even if some game somewhere uses a similar mechanic, this will turn into your own thing in the development process.
(And even if not, if Paizo can just steal D&D 3.5 and publish Pathfinder, you can steal a dice mechanic from somewhere else ;) )

Ah, no you don't add the dice, you only look at the individual die result. I did not explain that. If you roll 2d6...you check each result. So a d6 gives you a 50/50 chance per die. Where a d8 gives you...and this is where my math may be off...a 70% chance at one success and a 12% chance at two successes. Or something like that.

Yes, I agree. I'm not that worried, because at this point I'm not planning to publish, but I might and I just want to take precautions. If someone knows of a system that is similar, I would want to check it out for similarity issues. It's really just a minor issue for me at this point.

Have you ever played the Cortex RPGs?

You have a lot of elements that are very similar to that, in your thoughts here, but different too... I'd recommend checking it out, cuz it's an awesome game, if for no other reason.

I was going to say the same. If you call it a setting or whatever and change something, you're probably safe on the copy right side (but I am far from a lawyer, so don't take my word :D )
oh! you don't sum? let's see... that may make the stat's balance worse in terms of progression... ahah, just google dice simulator or something and you get all the stats ;)

You can also spend ages trying to understand the statistic like I did :D
This table is value rolled on rows and Ds on columns. The % is to roll that or above. (not double checked)


The effects are independent so that means something... like... you can sum the %s... I think :)

The only Cortex game I know is Smallville and I don't really see any similarities there to this idea. What part in particular do you mean?

Bowl is a cultist of Cortex :D

I'm not sure how to break it down on the larger dice. A 1-2-3 on any die is not a success. 4-5-6-7 is one success. 8-9-10-11 all mean two successes, 12-13-14-15 is three, and so on. So the chances of getting "at least one success" is easy to calculate with simple math. The odds of getting "more than one success" on the larger dice are where the math gets to tricky for me to calculate.

Both a d8 and a d10 offer the option to get "at least one success" and "two successes" but dividing up the faces confuses me. I never took statistics in school.

@CSEN - That table is exactly the kind of thing I was looking for. Now I just need to figure out if you are right about the balance in the upper results.

So the %s for each number are the same (1/sides). You sum the number of values that are 1 or 2 successes and divide by the dice sides.

let's try, getting 3 success with a ... 1d10 (3d6) + 1d8 (2d6), which are the 5AD merged...

for the d10 you have:
* 3 values that will result in 0 successes -> 30%
* 4 values that will result in 1 successes -> 40%
* 3 values that will result in 2 successes -> 30%
for the d8 you have:
* 3 values that will result in 0 successes -> 37.5%
* 4 values that will result in 1 successes -> 50%
* 1 values that will result in 2 successes -> 12.5%

You need 3 success so you either get:
1 from d8 and 2 from d10: 50% x 30% = 15%
2 from d8 and 1 from d10: 12.5% x 40% = 5%
2 from d8 and 2 from d10: 12.5% x 30% = 3.75%
Sum that up: 23.75%

So the take away I'm getting, is there is very little reason to go all the way to a d20 unless you need a lot of successes from one die. You are better off getting as many d10s as you can and just rolling those.

Is that how anyone else sees it?

I'm not exactly discouraged by this news. There are a lot of factors like setting difficulties and taking damage that I haven't gotten into on this thread that I think make the risk/reward gamble interesting. This just helps establish the base line of an uncontested series of dice rolls.

Like, the fighting isn't factored in. You need to potentially save dice to defend, or take multiple actions in a turn.

well, I wouldn't go that far. Just said there was a little thing inside me that was worried about how worth it is to merge. For example, there is a massive leap between d12 and d20, that there is not between d8 and d10. Maybe you need to drop one of the merging steps, maybe you need to add more merging steps. It may even just work as it is :D I agree with bowl, it does need to be played how to get a feel for it's workings in practice. The choice between more actions or bigger dice may be the balancing factor for all I know! It definitely adds an interesting strategic dimension to it

Definitely don't want to discourage you. I think this looks like a great concept
Since you were unsure about how to get the stats, I just gave you a little push ;)
By the way, do you know why wizards dropped this system? there may be important clues there :D

Yes, this was a nice little push. I have some outside opinions that aren't absolutely blasting my ideas. The impostor syndrome was starting to get me, so it was good to put it out there. I think I will start writing things up for consumption by others and try a short "session"

Well...I don't have specifics on why Wizards dropped it. What I remember reading was it got to far away from the "core" of how D&D typically worked. So, the Fighter/Battle Master is the only obvious element left from those early designs, but if you go back to the introduction of the Sorcerer, that class had a pool of dice to work with. My thought is it turned into Sorcery Points, so the dice pool mostly powered Metamagic stuff and sometimes extra class abilities. I think the original Draconic Bloodline had an affect like a breath weapon that you could spend the dice on. I was really hoping they would go with it for all the classes, but it may have made them feel to similar to each other, which was a complaint I heard about 4e...that class was the same, they just had some slightly different tricks to work with here and there. That isn't my opinion, I loved 4e. It wasn't perfect but it was fun for what it was. It did feel a bit like WoW on my dining room table though, just waiting for cool downs to happen.

You assemble a pool of mixed dice, based on varying stats, and you roll them to try to hit a target number.

It has the Effect die element, and the structure isn't the exact same, but there's a lot I think OP would find interesting in it.

I do like the Cortex stuff. I really liked my short experience with the Marvel game. I played a Power Man & Iron Fist vs. The Circus of Crime. It was cool.

Here's an anydice output to give you an overview of what you're looking at: https://anydice.com/program/1b4b2

This view adds another layer of strategy to your rolls:
-- If you really just need one success, you ramp up both dice as much as you think you can afford. This gives you a slight edge over ramping up one die all the way. It's not much, but it's there.
-- If you want multiple successes, you ramp up one die all the way. This is more pronounced in the midrange.

I don't wish to start that old debate here of edition wars. I do want to highlight, though, that the cool downs are still present in 5th. It's just worded differently with short rests, long rests, etc.

Anyway, I'm not sure of how practical your suggestion is for D&D as a whole, but I do like the idea of more dice instead of simply bigger dice. I like bard's inspiration dice (fun fact, like twenty years ago I made my DM come up with inspirations for one of my characters and he basically created a similar mechanic to the bard's in 5e). I haven't played battlemaster, but the mechanic sounds cool.

I say run with your idea and create a design doc for it. You never know. Maybe you can submit it to Wizards or publish it on dmsguild or something.