I've really hit a stumbling block coming up with a good core dice mechanic for my homebrew game.

There are four levels of stats/ability scores: Poor, Fair, Good, Exceptional

There are four skill levels: No skill, Basic training, Advanced training, Mastery

The idea behind the game is to make things as simple as possible, and to remove  a lot of the wacky randomness that can occur with too much reliance on dice.

My basic requirements/preferences at this stage are:
-D6 only.
-The fewer dice the better.
-Bell curves are better than linear distributions.
-I don't want to add too many dice together. Adding two dice is fine, three is pushing it and four would be too many.

I'd like most rolls by a player to involve between 2 and 4 dice.

I'd also like to make it scalable so I could do more powerful creatures or supers by ramping up something (like increasing the number of dice or boosting the target numbers).

A few things I was thinking of:
2d6 + stat + skill vs TN: This has a problem of the range of dice results being greater than the range of stats and skills.

Difference Dice: Roll 2d6 and take the difference between the highest and the lowest. I like the bell curve that this generates but I can't quite get how to scale this for more powerful characters.

Dice pool: One die for each point in a skill with either a fixed TN or using the stat as a TN somehow. This option is scalable, but I haven't quite figured out the details yet.

Help me Obi Wan! Throw some ideas my way.

-Jeff

Quote from: GoOrange-Jeff

Hey Jeff:

Dice pool - Roll Skill dice under Stat TN.
Count successes, add situational modifiers like weapon damage.
Vary dice to scale - d10 = standard, d8 = cinematic/Pulp, d6 = Low Supers, d4 = Supers.

That OK?

-clash

You could check out the CODA system used for Star Trek and LoTR, I guess. That system used 2d6, didn't it? I think Classic Taveller used a 2d6 system as well. These might give you ideas for your own system.

Roll Under the square root of Skill (1-3) squared x Stat (1-4) on 1d6

Increasing levels of difficulty could be represented by different dice types or a dice pool roll.

Say: Difficulty 1-5 dice with 3 being average and requiring a success on all dice?

Let's get down to 1d6 shall we?  Make the target number Skill squared times Stat divided by difficulty and devise a bidding system for handling the fractional points.

What?

Quote from: flyingmiceHey Jeff:

Dice pool - Roll Skill dice under Stat TN.
Count successes, add situational modifiers like weapon damage.
Vary dice to scale - d10 = standard, d8 = cinematic/Pulp, d6 = Low Supers, d4 = Supers.

That OK?

-clash

I'd really like to stick with d6, although if I used others it would certainly open up more possibilities.

I've thought about the skill= # of dice and stat=TN. With d6, the target number breaks down if someone has superhuman strength, for example. If the TN is 7 every die will automatically be a success. Scalability becomes tricky if I stick to the single die type.

I'm still considering some type of dice pool, I like the idea of having certain circumstances give bonus dice.

Maybe a roll and keep system like L5R.

Another idea I liked was a roll (skill)# of dice, keep highest result.

Quote from: David JohansenWhat?

You know you're insane, David!

-clash

Quote from: Sacrificial LambYou could check out the CODA system used for Star Trek and LoTR, I guess. That system used 2d6, didn't it? I think Classic Taveller used a 2d6 system as well. These might give you ideas for your own system.

I'm not familiar with CODA, can you brief me on the basics of task resolution?

I've thought about Traveller, and I really like the 2d6, but the problem is it produces a spread of numbers between 2 and 12, where the combination of stats and skills could at most provide 2-8. Therefore in this instance the random roll eclipses the game stats. I could just use 1d6, but that's starting to become boring.

Quote from: GoOrangeMy basic requirements/preferences at this stage are:
-D6 only.
-The fewer dice the better.
-Bell curves are better than linear distributions.
-I don't want to add too many dice together. Adding two dice is fine, three is pushing it and four would be too many.

As an FYI, you need three dice or more for a proper bell curve (unless you create the curve with something like a conversion chart or unconventional reading of the dice).

Point taken John, I should have just said I prefer curved rather than linear distributions.

Quote from: flyingmiceYou know you're insane, David!

-clash

Do the math and tell me I'm wrong.

Quote from: David JohansenDo the math and tell me I'm wrong.

I didn't say you were wrong, I said you were crazy!

-clash

It's hard to argue with someone who starts with the premise that you're crazy.

I didn't say that was a bad thing either!

-clash

Quote from: GoOrange...
I've thought about Traveller, and I really like the 2d6, but the problem is it produces a spread of numbers between 2 and 12, where the combination of stats and skills could at most provide 2-8. Therefore in this instance the random roll eclipses the game stats. I could just use 1d6, but that's starting to become boring.

In my experience playing Classic Traveller a +4 on 2D6 is pretty much a guaranteed success, because the base target number is not 0.  The non-linear nature really makes a +2 or +4 much more determinative than one would think from linear mechanic experience.  I guess my view is in a non-linear mechanic you don't really need the modifier to span the whole range of rolls to get a highly skill determinative system.  I've seen this as a complaint of Classic Traveller not random enough, "high skills" (+4 mod.) make missing near impossible.

I like using the different types of dice for levels of "heroism" you could also do the same with levels of skill.  I can see of course if you want to stick with D6 for design and ease reasons.

Quote from: XantherIn my experience playing Classic Traveller a +4 on 2D6 is pretty much a guaranteed success, because the base target number is not 0.  The non-linear nature really makes a +2 or +4 much more determinative than one would think from linear mechanic experience.  I guess my view is in a non-linear mechanic you don't really need the modifier to span the whole range of rolls to get a highly skill determinative system.  I've seen this as a complaint of Classic Traveller not random enough, "high skills" (+4 mod.) make missing near impossible.

I like using the different types of dice for levels of "heroism" you could also do the same with levels of skill.  I can see of course if you want to stick with D6 for design and ease reasons.

Intersting take on Traveller, I hadn't thought of it that way. The lower the target number, the more important the skill level becomes (with a 2d6 roll).

Still this breaks down again with opposed rolls, where if two people, one with +2 and anothre with +4 square off, their individual skills will be less of a factor than their die rolls.

When I described the various skill levels, I deliberately didn't apply a number because the actual numerical value doesn't matter to me. Just because there are only 4 levels of skill deosn't mean they have to be valued at 1-4. I could increase their numerical value to make that greater compared to the range of dice results. For instance:
No skill = 0
Basic = 4
Advanced = 8
Master = 12

These values added to a 2d6 might produce a better range of results for my purposes, so that someone with skill mastery would have a clear advantage over someone with basic training.

This might work well with abilities too, giving poor=3, fair=6, good=9 and exceptional=12. For supernatural levels (cybered reflexes, a vampire's speed, or super-strength) I could just have increasing #values. So a vampire could have a speed of 15 compared to a human's max of 12. Superman could have ridiculously high strength of 50 or similar. Mostly I would want to target things at human level action, so the exceptions aren't as big of a deal.

I should note that I am undecided how much to tie in stats to skill rolls in a system like this, if I should do a stat + skill or just skill + roll, with skills having different costs based on your stat. If I used a dice pool method, I could consider Clash's idea of using one for the pool and the other for the TN, but I'm still hashing this out.

Different types of dice

I'm not terribly opposed to using different die types when all is said and done, (but I really like limiting things to just a few d6). If different dice are used, however, the system would have to be one where only one of each type is used at a time (other than 2d10, which most sets of dice come with). One thing I don't like about a system where each skill level is represented by a die type (like basic=d6, advanced=d8, mastery=d10) is that the really skilled types can still get hosed with a low roll. Savage worlds fixes this by adding the wild die, but I'd rather not completely rip off another game.

I'm not trying to overly criticize anyone's ideas, just bouncing thoughts around in my head until something really clicks.