2d10 for Skill Checks

[DEFCON 1]

Hmm, I was ready to discount this when I read the subject but it's actually quite interesting. Do you do it for attack rolls and saves as well?

Interesting. Why are you using that method and not rolling your 2d10 twice? And have you tried applying it to other d20 rolls?

I decided not to do with with attack rolls for the simple reason that every single character at both tables have their primary ability score modifier for attacks either starting at a +2 or a +3, and all of them apply their proficiency bonus (because PCs just don't make attacks with things they aren't proficient in, unless its a particular story point I've put them under.) So with everyone making their attacks at like a +4 or +5 (and only a little different in some extreme cases), there is much less need for modifiers to have more of an impact. With skills, people can be rolling checks with modifiers ranging from like -1 to +7... that's an 8 point swing. With a "pyramid" die roll range, those 8 points have a much wider effect on checks than attack rolls that might only have 1 or 2 points of modifier difference.

Thus the need for a "pyramid" die range for attack rolls I felt was unnecessary. And to be honest... combat has so many crazy parts to it (with features, spells and the like) and so many more bonuses and penalties of varying die sizes handed out from different classes... I was less certain of how any balance might work out if I tried combat as 2d10. Especially considering that each additional die added to an attack roll (from say like the BM Precision Attack or Bardic Inspiration etc.) has much more of an impact in a 2d10 system. It ended up feeling more trouble than it was worth. And for saving throws? Pretty much the same thing... the d20 for saves never bothered me like they did for skills. So again, I decided to hold off on them.

I will say though, that I have had to make a couple adjustments for when attack rolls get defended against by skill checks (grappling situations with monsters being one of them), and for those I usually default back to the d20. I never want to have situations where there is a d20 vs 2d10 roll comparison.

As far as why I have advantage be 'roll 3 take highest 2' rather than just roll 2d10 twice? Mainly to just save time. The player can roll all 3 dice at once and choose what they need, rather than pick up and roll both dice two times, needing to add both pairs and compare. It's not a huge thing, but we like it.

Finally... rolling d8 + d12 was also a thought I had at one point as a possibility as well... but due to the fact that I've played a lot of 7th Sea and really enjoyed their multiple d10s dice mechanics *and* that I wanted advantage/disadvantage to be 'roll 3 keep 2' (which you really can't do with two different dice sizes)... I ended up being okay with the pyramid spread, rather than the center plateau.

 

[5ekyu]

Simple solution: have the players switch dice. That way the PC with the +6 could roll 16s to 20s while the +0 would roll 3s, 5s, 6s. Amirite?


On a more serious note, I have noodled over this before but concluded that the d20 just works. In the multiple dice method, any combo of dice is going to have results that strongly favor the middle of the range thereby lowering the chances of spectacular successes and failures. High and low rolls alike can create memorable moments at the table and reducing the chances of those would be a net loss, IMO (especially the failures ). As [MENTION=6987520]dnd4vr[/MENTION] demonstrates, rolling a 20 (or a 1) is 5x less likely to happen with 2d10 than it is with a d20.

In game, when there is a meaningful consequence for failing a check and so a roll is called for by the DM, the +0 PC could simply offer to Help (or Work Together with) the +6 PC. If that is appropriate in the given situation, the "problem" of the lesser skilled PC rolling higher goes away - instead they have teamed up to gain advantage and gain a better chance to succeed.

One might also argue that 2d10 for skill checks also somewhat diminishes the impact of the Rogue's Reliable Talent since it's less likely to roll less than a 10... or that it diminishes the value of Bardic Inspiration as the truly skilled PC won't need it as often... but maybe neither of those is really that significant...

That said, if 2d10 works for your table in a fun way, that's cool - and I'm glad you shared it!

Yup... I am in the same boat. If unpredictability is an issues, I find the die or dice is usually the scapegoat but the culprit is the DC.

Changing both the dice and the dc... double whammy. If you want 75% of the rolls to succeed set the DC appropriately and roll a single die, imo. If I want something to be more common, I set appropriate dcs.

I also use the proficiency = auto success on ability checks (DMG) that are easy or less, shifting the focus on reliability away from the dice to the character.

My experience with multi-die rolls has been that what it does for me in practice is make the "value" of traits highly variable. If the net modifier vs difficulty puts you near the sweet spot, your modifiers matter a lot. That bless 1d4 can be huge if you need to roll a 13 on 2d10. If they put you at the edges, that d4 may be almost trivial.

With a single fie, your modifiers have a flat constant impact anytime a roll is needed.

But, some like yo see things differently and hey, each table is different.

 

[DND_Reborn]

We are playing Sunday and I'll bring this up to the group. There isn't a vast difference between 2d10 and d8+d12, so I'd be fine with either. My only issue is that one of our players is very bad at math, even simple stuff, and having to add two dice when he does most things will slow things down. I don't know, we'll see.

On the other hand, I don't really have much issue with d20. I've always seen that changes in the DC, AC, etc. are what changes the probability, not switching to a non-linear system. But, whatever makes your game better is awesome.

 

[S'mon]

Certainly makes sense to use 3d6 or 2d10 for ability checks instead of d20 for attacks and saves.

 

[Harzel]

Knowing that most skill modifiers for most PCs will fall in the -1 to +4 range (basically anything that isn't a high ability + proficiency modifier and/or Expertise)... the bell curve will usually give me rolls in the 9-13 range and thus produce most modified results between like 10 to 17.

If I understand your intent here, I think that range for modified results should be 8 to 17.

 

[TallIan]

You cover the main advantage of 2d10.

The main drawback with using 2d10 (or any dice combination) is that is obscures the results. A linear distribution is really quick to work out the probability of success and doesn't require any good understanding of stat's. Every number up or down is a 5% difference in probability.

So if you are playing with a group of maths nerds great, if you have any players that don't easily grasp the maths of 2d10 then its probably not a good idea for this change.

 

[Blue]

I have run many, many games now over the years that have used the standard d20 for skill checks, and over time have grown more and more disillusioned with it. Principally due to the fact that the d20 die roll produced way too large a variance for me, resulting in a PC's personal modifier having much less meaning in the grand scheme of results. A PC with a +6 to a skill versus one with a +0 did not make a perceptional difference that often... when the +0 could roll 16s to 20s while the +6 would roll 3s, 5s, 6s etc. The lack of a bell-curve meant modifiers had less import.

As a result of this, I decided for my two new Eberron games that I just started this past fall that I was going to replace the d20 with a 2d10 system for skill checks-- roll 2d10 and add your modifier. And due to the fact that this would now produce a bell-curve (bringing almost half the die rolls into the 9 to 13 range and very few at the extremes) a PC's ability modifier + proficiency would have a much greater impact.

Mathematically, you have introduced a much greater variance. You are heading in the opposite direction of your stated goal.

This is because the variance isn't about the number, it's about the boolean pass/fail nature of it. It doesn't matter if you succeed by 1 or succeed by 8. Only if you pass or fail. Therefore, the only variance you are actually looking at is the one right under the needed roll.

With your projected DCs, you're aiming at the top of the bell curve often. At that point, a +1 difference will have a lot more affect than with a d20. If you go from needing on the dice a 10 or more to an 11 or more, that's an 11% change in your chance to succeed vs. only a 5% change with d20. You go from having a 64% chance to success to a 55%. Moving from an 11+ to a 12+ is another 10% change.

As a matter of math, the only place that 2d10 produces less variance than a d20 is if you need the dice to give you the extremes - you succeed of a 5+ (or even lower), or a 18+ (or even higher) on the dice.



A bell curve increases the variance at the target numbers you are aiming at, so means there is greater uncertainty then if you were just rolling a d20. It doesn't feel like it because the numbers are grouped closer, but since how much you make or fail the roll by doesn't matter that's a false perception.

 

[DEFCON 1]

The perception of the extremes are what I had problems with. A +0 modifier has a 20% of hitting 17+ on a d20, and a 10% chance on 2d10. I wanted the lower percentage of high DC success because it put more emphasis on the modifiers to hit the higher numbers than the die roll did.

 

[DND_Reborn]

The perception of the extremes are what I had problems with. A +0 modifier has a 20% of hitting 17+ on a d20, and a 10% chance on 2d10. I wanted the lower percentage of high DC success because it put more emphasis on the modifiers to hit the higher numbers than the die roll did.

So, basically what you wanted was this...

Original d20 version

A character with a +3 needs 17 or higher for DC 20, or 20% chance of success, a character with +0 needs a 20, only 5%. So, that +3 modifier increases the likelihood of success by 300%.

New 2d10 variant

A character with a +3 needs 17 or higher for DC 20, or 10% chance of success, a character with +0 needs a 20, only 1%. So, that +3 modifier increases the likelihood of success by 900%.

Obviously on the 2d10 variant having a modifier with this DC drastically improves your chances of success over not having a modifier. Of course, since d20 is linear, here you have a better chance of succeeding on the DC just rolling the d20, but that is what you don't want. You want the higher DC's to be harder to make if I followed everything correctly. Now, let's examine the other end of the spectrum...

Original d20 version

A character with a +3 needs 7 or higher for DC 10, or 70% chance of success, a character with +0 needs a 10 or higher, so 55%. So, that +3 modifier increases the likelihood of success by 27.3%.

New 2d10 variant

A character with a +3 needs 7 or higher for DC 10, or 85% chance of success, a character with +0 needs a 10 or higher, so 64%. So, that +3 modifier increases the likelihood of success by 32.8%.

In both situations, the 2d10 variant makes it so the modifier has more impact on the likelihood of success. That was your goal, right?

 

[DEFCON 1]

In both situations, the 2d10 variant makes it so the modifier has more impact on the likelihood of success. That was your goal, right?

Yup. I wanted higher modifiers to have more impact on success.