Howdy all,

Long-time lurker, first-time poster here. Some friends and I are designing a class-less (and probably level-less) fantasy RPG, and I was hoping you fine folk could give us some feedback on our core resolution mechanic. For context, here are our primary goals for the system:
- Uses a unified mechanic to resolve checks both in and out of combat
- Can handle multiple modifiers from multiple sources without becoming unwieldily
- Magical- and martial-focused characters are of equal power and use similar mechanics
- Combat is matter of tactics and decisive blows, not attrition (we REALLY want to avoid having combat consist of trying to use up the enemy's resources faster than they can use up yours, as D&D tends to do)

Dice
The core system mechanic is a success-counting dice pool system incorporating three different dice sizes. d8s are Standard Dice; they count for zero successes on 0-1, one success on 3-6 and two successes on 7-8. d6s are Demoted Dice; they count for zero successes on 0-3 and one success on 4-6. Lastly, d10s are Promoted Dice, which give zero successes on 1, one success on 2-5, two successes on 6-9, and three successes on 10.

Attributes and Skills
Characters have six primary attributes, each typically ranging from 2-7 points, and may also have 0 to 5 ranks in any number of skills (the system has about 18 skills total). To make a check, you roll (Attribute + Skill ranks) d8s versus a target number, or against the number of successes rolled by your opponent (if the check is opposed). The number of successes you get over the target number determines how well you did; a tie may require an additional check to actually get the job done, while beating the target number by 4 or 5 successes means you've won a flawless victory.

Bonuses and Penalties
Bonuses to your roll allow you to "promote" some number of dice up to d10s, increasing the number of successes you're likely to roll, and penalties "demote" dice to d6s, decreasing your odds. Demotions and promotions cancel each other out. One interesting consequence of this is that you can never have more net promotions (or demotions) to a roll than you have dice to begin with, which means that together your Attribute and Skill set a hard limit on how high you can buff your roll.

So there you have it. Thoughts? Comments? Does it make sense? Does it sound playable? Does it sound fun?

What would be the reason for multiple successes split over the dice results rather than simlifying it to 0/1/2 successes and just lowering the difficulties? Then you could simply use the same spread over the three dice types:

1-2 - zero successes
3-5 - 1 success
6+ - 2 successes

The design goals seem fine.

Having different difficulties for the different types of dice is going to  makes it much harder to remember the difficulties and slower, particularly with pools of mixed type. As with any dice pool system, you have fairly nontransparent probabilities.
Minor thing but as in any Stat+Skill dice pool game, raw attribute contests like a STR check to arm-wrestle someone are much unpredictable than a skill contest since the dice pools are smaller and so much more likely to roll mostly good or mostly bad.

The buff/debuff limit is interesting, but, could be good or bad depending on how well that feature fits the situation (there may be circumstances so beneficial someone should succeed despite lack of ability; in which case you end up either not rolling, or adding some kludge like extra buffs turning into bonus dice or something).

Quote from: TristramEvans;673094What would be the reason for multiple successes split over the dice results rather than simlifying it to 0/1/2 successes and just lowering the difficulties?

We had considered using this method to make it easier for players to read the dice; however, we decide to go with the current system because the probabilities are symmetrical (i.e., each promoted or demoted dice modifies the roll's average number of successes by .5). In contrast, when we had the same difficulties on all dice sizes, the difference between a d6 and a d8 was much bigger than between a d8 and a d10. Here's the probability with the difficulties flat; for comparison,here's the probability with the difficulties as originally proposed.

Quote from: Bloody Stupid Johnson;673099Minor thing but as in any Stat+Skill dice pool game, raw attribute contests like a STR check to arm-wrestle someone are much unpredictable than a skill contest since the dice pools are smaller and so much more likely to roll mostly good or mostly bad.

Hmmm, that's an interesting point... I would've thought it would be the other way around, actually, since the variance of the rolls increases the more dice there are. Math, man

Quote from: Bloody Stupid Johnson;673099The buff/debuff limit is interesting, but, could be good or bad depending on how well that feature fits the situation (there may be circumstances so beneficial someone should succeed despite lack of ability; in which case you end up either not rolling, or adding some kludge like extra buffs turning into bonus dice or something).

Yeah, I still can't decide whether the buff/debuff limit thing is a bug or a feature.

One other option we were considering was a more traditional d6 dice pool system in which your attribute determines # of dice rolled and your skill determines target number on each die. An Untrained roll counts 5s and 6s as successes, Trained counts 4 and higher, Adept counts 3 and higher, and Master counts 2 and higher. A six always counts for an extra success. Modifiers would just add or subtract dice from the pool. What are the relative merits/flaws of a system like this?

Ah, you got me there.

In the alternate system, with 6s counting double, skill level is altering your expected successes from 50% of the pool (Novice) to 100% (Master), so I suppose attribute is probably a higher factor in determining success, depending on how its scaled. Higher skill levels get more mileage out of a bonus die.