D&D 5E 3d20 variant for 3d6/2d10 to replace d20. Thoughts?

[CleverNickName]

EDIT: Thanks for the feedback. Given the information people have shared/ brought up I think we will probably NOT use this idea for attacks, but might use it for skill checks and saves. If you have any additional input, please still reply to the thread. Thanks to all!

I think that would be for the best. A lot of players would immediately complain about how you are trying to nerf their critical hits, but the reality is you are all but guaranteeing their success on every roll with a +6 modifier or higher. Maybe 2d10 would be a little better, but meh. With bounded accuracy being what it is, I'd stick with d20s. It's not worth the arguments and math.

 

[Esker]

Another comparison graph: if you leave advantage and disadvantage alone, here's the effect of advantage on the chance of success for different thresholds, compared to the effect relative to the ordinary 1d20. (The success chances with advantage are the same, but we're boosting them from a different baseline). Note that with the 3d20 keep middle base roll, advantage becomes somewhat less valuable on easy rolls, and somewhat more valuable on difficult rolls, being the equivalent of a +6 on rolls when you need a natural 14 or 15 to succeed. I actually kind of like that, since it encourages characters who don't have large bonuses to find sources of advantage to overcome difficult challenges, still allowing them a good chance of success if they can get it. For example, a character with a low athletics bonus trying to make a difficult climb gets even more mileage out of a climber's kit with this system.

 

[Esker]

On the other hand, for rolls that would normally have been moderately easy (7-8 needed to succeed), disadvantage becomes really devastating; it's more of a handicap than under RAW just because you've boosted the baseline success chance for these rolls.