In my home brew; I've written out instructions for D20 Roll High, D20 Roll Under, and 2d6 Mechanics.

I'm personally leaning toward 2d6 forever; but if I receive a credible complaint, I'm ready to switch over to d20.

I like 2d6; with -2 to +3 modifiers, etc.

So therefore; I could see the appeal of 2d10.  If that's what the DM likes, they should give it a go.

Quote from: Theory of Games;1087359Longsword vs. Scimitar.

The d20 is flat as hell. 2d10 provides a nice curve for character success.

d20 is so popular but at a cost of utility. 2d10 allows a level more roll-to-roll.

But, what are your experiences with d20 and 2d10? Is d20 really keepsake or no?

Your responses indicate a lot regarding how the D&D-related d20 has impact.

Thanks.

Speaking for myself, I don't see any utility in the 2d10 mechanic. I see a lot of dis-utility in it. I'm really indifferent to modern D&D's use of the d20.

If you're interested in 3d20 take mid, you might find this interesting:

Quote from: M&M 3E (OGL)Another means of adding a "bell curve" to M&M die rolling is by using high-low rolls: in place of any single d20 roll, roll three 20-sided dice and take the middle number (dropping the highest and lowest). If two or more dice come up the same number, use that number (since the third die is by definition higher or lower).

This method tends to produce results weighted more toward the middle range, with 10 as the average. Rolling a "natural 20" requires two of the dice to come up 20 (about a 1-in-400 chance or 0.025% rather than 1-in-20 or 5%). The same is the case for a "natural" 1. Generally, this means characters achieve the effect of their routine checks more often, but succeed at high Difficulty tasks less often, and have fewer critical successes or failures. High-low rolls involve more dice, but are only slightly more involved than rolling and reading a single d20.

Spending a hero point with high-low rolls allows the player to keep the best die roll of the three dice rather than the middle roll. So a roll of 4, 11, and 18 would normally count as an 11. Spending a hero point makes it an 18 instead. If all three d20 rolls are below 11, take the highest and add 10 to get the result of spending a hero point on that roll.

Quote from: Lunamancer;1087446Speaking for myself, I don't see any utility in the 2d10 mechanic. I see a lot of dis-utility in it.

What is the dis-utility in 2d10?

Quote from: Aglondir;1087376The d20 is good for combat, where the wild swings feel appropriate. And everyone loves rolling a natural 20.
But it's not so great for skill checks (where single rolls determine the outcome.)

Exactly this. Which is why I don't favor 1D20 roll under attributes for "skill checks". Instead I like to use a modified reaction roll table - roll 2D6 add attribute / situation mods and generate a non-binary, bell curve result. But in combat, yeah, I'll just stick with the D20 - things should feel chaotic and unpredictable.

Quote from: Aglondir;1087468What is the dis-utility in 2d10?

Probabilities are less obvious.
Intervals are uneven.
Lower resolution in the middle where 80% of the game is played.

Just to name a few of the easy ones.

Quote from: Aglondir;1087376The d20 is good for combat, where the wild swings feel appropriate. And everyone loves rolling a natural 20.
But it's not so great for skill checks (where single rolls determine the outcome.)

These days I think I'm leaning more to the opinion that its skill checks that are the problem not D20s.

Quote from: Beldar;1087397So many of these dice threads suggest somehow that a bell curve is somehow superior to a linear distribution. It doesn't model reality either way.

Wrong.

The central limit theory says that when many random distributions contribute to an overall result then the probabilty distribution tends to a bell curve.
https://en.wikipedia.org/wiki/Central_limit_theorem

The example that I show students is data for average speed of cars in different speed limit zones. So - that's averaged over many cars (brand, model, age, conditions), many drivers (age, sex, experience) and many weather conditions.  The distributions - basically a bell curve.

I need the "Math People" to come out here because --- 1d20 is evil. If it isn't --- okay.

I try not to use d20 but it calls me. I like the whole of what's been posted here. I like 'hands on my head looking for change with no clear vision' action.

*shaking two d10s*

Id rather just go percentile rolls. :cool:

Part of the problem is the very bell curve you are touting.

In D&D going 2d10 instead would totally fail the system. You'd need a new system to accomodate the curves peak. You might as well design your own game like others have.

Quote from: Omega;1087502Part of the problem is the very bell curve you are touting.

In D&D going 2d10 instead would totally fail the system. You'd need a new system to accomodate the curves peak. You might as well design your own game like others have.

Well it would cause problems if you used it in combat.

If you just used it out of combat I don't really see any issues.  The average is slightly higher - 11 instead of 10.5, but that's negligible.

There's no intrinsic reason why you must use the same die rolling mechanism in all circumstances.

More food for thought:

Quote from: Unearthed Arcana (OGL)Metagame Analysis: The (3d6) Bell Curve

Game balance shifts subtly when you use the (3d6) bell curve variant. Rolling 3d6 gives you a lot more average rolls, which favors the stronger side in combat. And in the d20 game, that's almost always the PCs. Many monsters--especially low-CR monsters encountered in groups--rely heavily on a lucky shot to damage PCs. When rolling 3d6, those lucky shots are fewer and farther between. In a fair fight when everyone rolls a 10, the PCs should win almost every time. The bell curve variant adheres more tightly to that average (which is the reason behind the reduction in CR for monsters encountered in groups).

Another subtle change to the game is that the bell curve variant awards bonuses relatively more and the die roll relatively less, simply because the die roll is almost always within a few points of 10. A character's skill ranks, ability scores, and gear have a much bigger impact on success and failure than they do in the standard d20 rules.

Quote from: Aglondir;1087534More food for thought:

So one beef I have with that, which I guess permeates this entire discussion, is if I were designing an RPG and statting things out with 3d6 in mind, I wouldn't assign the same stats I would have if I were writing with a d20 in mind.

Using 3-core AD&D 1E for example, because I'm very familiar with it:

The best armor in the game, plate & shield, gives AC 2. The worst, unarmored, AC 10. The average man (0th level human) needs a 19 to hit AC 2, an 11 to hit AC 10. On a d20 that means the best armor effectively blocks 90% of attacks (the average man being the baseline). And for a regular guy to hit someone unarmored? Even odds, 50/50.

If I were designing the game with 3d6 in mind, I would NOT preserve the existing THAC0's and AC's of the game. That's all just nonsense anyway. Abstract game concepts. What I really care about is what the numbers stand for. Which is to represent the best armor as repelling 90% of blows as a baseline, and no armor to be a 50/50 chance. Thus under a "d20" style system, but using a 3d6 mechanic, I'd probably give the 0th level human a +0 BAB, and the AC of platemail and a shield would be 15. Unarmored would be AC 11.


This brings me to note a few things.

First, this only gives me 5 categories of AC instead of 9. If I like more detail or variety or a higher res game, this is certainly a problem.

Second, there is no bell curve. Under either system. The numbers on the dice roll, just like the game stats, are abstractions and meaningless by themselves. Their effects are what have meaning, and in this there are only two outcomes, hit or miss. Two outcomes will never look like a bell. And they will be just as even or uneven as they would under a linear mechanic.

Third, those lucky hits weak creatures deal to threaten PCs as mentioned in the quote would thus be just as common under either system.

Fourth, just as I would have adjusted my game numbers in my design with the die mechanic in mind, I anticipate players and DMs will also adjust.


So I feel there's a pretty major disconnect in this discussion between doing math and what the numbers actually mean.

Quote from: Lunamancer;1087556So I feel there's a pretty major disconnect in this discussion between doing math and what the numbers actually mean.

Not really.  It's simply that most everyone is taking shortcuts in the discussion, which makes it appear to be a disconnect.  It's when you model the reality of how competent a population is at a skill that prompts the desire for a distribution with a curve instead of linear.  

In a curve, a modifier of +1 has a different meaning at different levels of competency.  This happens to model somewhat well against the curve of competence in reality.  Not perfectly, but better than a linear distribution with equal modifiers.  There tends to be rapid learning at first, followed by slowing learning, followed by more and more work to eke out any significant advantage.  If one wants to use small modifiers that change meaning over this range of competency, then a curve starts to look fairly good.  Of course, you could get a very similar effect with a d20 or another linear roll by monkeying with the modifiers to make them relatively scarce for beginners and experts and common for those in the middle.

When I say I prefer the 2d10 for this model over the 3d6 or 1d20, that's shorthand for I find that the percentage chance of success using +1 modifiers on a 2d10 maps reasonably close to the skill curve that I want, both mathematically and aesthetically.  (Not least because I want something akin to reality, but skewed to fit a particular style of fantasy.)  Furthermore, while the odds are more difficult than the d20, at least the 2d10 odds map to 1% increments with each jump.  Show a normal player a map of the results of 2d10 with the percentages for each roll, it intuitively makes sense to many of them.  (That's why I prefer the 2d10 to 2d12.  I like the spread and results of 2d12 even more, but not enough to give up the ease of understanding for most players.)  A mechanic needs to balance all of these concerns in a way pleasing to the players.