Suppose we substituted 3d6 for a d20 roll?

[Thomas Bowman]

Here is a chart for approximate conversions between d20 rolls and 3d6 rolls:

A short little explanation in in order.
For everything we'd ordinarily roll a d20 for we roll 3d6s instead, not just any 3d6s but specifically 2d6 consisting to two white dice plus 1 red d6, you add them up normally to get the result, but for the middle range, you consult the red die if there are two possible d20 values for one 3d6 result you check to see if the red die result is either an even or an odd number, if there are three possible values you check the red die to see if it is on the range of 1-2, -4, or 5-6 to determine which one. The advantage of rolling 3d6s is that it extends the range to 22, though the changes of rolling an 18 to get the equivalent of 22 is small, 1 in 216 for an unmodified 3d6 roll. The usual rules apply, a 3 instead of a 1 is an automatic miss or failure and an 18 is an automatic hit or success. The chances of rolling a 3 or an 18 on a 3d6 are smaller than rolling a 1 or a 20 on a 1d20. What do you think of this?

 

[JacktheRabbit]

What do we gain other than more math at the table?

 

[Aldarc]

What do we gain other than more math at the table?

Presumably a bellcurve distribution of die results. I'm just not sure why there appears to be a jump from a simple 3d6 system to one that distributes 3-18 to one that distributes from 3-22 by consulting an off-colored die. That seems like the needlessly complex part. I don't see why, for example, one couldn't just make it 4d6 instead rather than this confusing system.

 

[JacktheRabbit]

If we wanted to create a bit of a bell curve then we could just roll 2D10. Of course just like rolling 3D6 you are never going to critical fumble.

 

[Aldarc]

If we wanted to create a bit of a bell curve then we could just roll 2D10.

That is another option. There are many ways to create bellcurve depending upon what you want to achieve with the dice rolls.

Of course just like rolling 3D6 you are never going to critical fumble.

Yeah, but that seems to assume that critical fumbles are necessary. I'm not entirely sure. Again, it depends on what you want.

 

[ccs]

I think I'll just stick to rolling 1d20. Seems to have worked well enough for me all these years/editions.

If I wanted to play a game with some fiddly dice combos I wouldn't be playing D&D....

Oh, and D&D without the d20? Just isn't D&D.

 

[Sunseeker]

God. Only nerds can take a simple system of "Roll a d20" and turn it into a complex mathematical equation.

No. Seriously. What is the gain? You have taken a one-step process and turned it into a 3-step process.

Look, I'm down for rolling 3d6 straight if you're looking to reduce the statistical chance of generating extremely low numbers (and taking some numbers off the board entirely). It's the reason why we roll 3d6 for stats instead of a single d20. You're more likely to produce reasonable numbers.

But this isn't that.

 

[Jhaelen]

Yup, the big question here is why would anyone want to replace d20 with 3d6?

Apart from that, doesn't GURPS use 3d6? Just play GURPS!

 

[dbm]

If you want a bell curve (personally I’m a fan...) then just roll three d20s and use the middle dice result. Bell curve, no extra maths, just number comparison.

Interacting with Advantage is a little more tricky to shake out.

 

[Jacob Lewis]

Having used a 3d6 substitute for d20 rolls as an experiment in an actual 4e campaign, I can voucher for the validity of such an idea, though the added table conversion is not needed. Our group found combat (where most of your important d20 rolls happen) went much faster and did not lose the normal tension or expectation. We also learned that the d20 is integral to many mechanical aspects of the game so we had to come up with some oddball solutions, like rolling low or high doubles for crits and auto-miss, and other minor comparisons which added some fun to the rolls and made d20 seem more bland than it already is. Bottom line, I do prefer any method to the simple d20. But the game needs to be designed for whatever mechanics it is built around. Straight 3d6 does have advantages if you're willing to work or compromise for it.