Thanks for all your replies, folks.
Let me start by clarifying that we only use 3d6 for ability/skill checks, and not combat or saving throws. I think the flat distribution of 1d20 works just fine for combat, since combat is supposed to be frenetic and random and everyone rolls dice much more often with the PCs all having similar to hit bonuses.
However, skill/ability checks are made less often and more usually hinges on each individual roll than in combat. Social scenes often turn on a single Charisma check, for instance. We've found that it suits our play style to have the characters reliably be able to shine in their areas of expertise and struggle if they stray outside those areas.
A couple of issues people have raised have been in line with our experience. Firstly, the impact of advantage/disadvantage is reduced mathematically, and that’s something we’ve noticed. This hasn’t been a big deal for us though, since we rarely use advantage/disadvantage for skill checks, but I imagine it could be more of an issue in other games.
Also, as you’d expect, ability/skill checks can become rather predictable. This isn’t to everyone’s tastes, of course, but for us it’s a feature rather than a bug. Outliers can still happen, and to add a bit of further uncertainty to the process, we’ve given results of 3-5 and 16-18 special outcomes (with 3 and 18 being particularly dramatic).
As many of you have pointed out, it would be easy to dial the bell curviness up or down by using 2d10 or 4d4 or whatever. I think 3d6 works well for us, but I would be interested to hear of anyone using something else.
And if anyone has used something other than 1d20 at higher levels I’d be very interested to hear what they have to say.
Let me start by clarifying that we only use 3d6 for ability/skill checks, and not combat or saving throws. I think the flat distribution of 1d20 works just fine for combat, since combat is supposed to be frenetic and random and everyone rolls dice much more often with the PCs all having similar to hit bonuses.
However, skill/ability checks are made less often and more usually hinges on each individual roll than in combat. Social scenes often turn on a single Charisma check, for instance. We've found that it suits our play style to have the characters reliably be able to shine in their areas of expertise and struggle if they stray outside those areas.
A couple of issues people have raised have been in line with our experience. Firstly, the impact of advantage/disadvantage is reduced mathematically, and that’s something we’ve noticed. This hasn’t been a big deal for us though, since we rarely use advantage/disadvantage for skill checks, but I imagine it could be more of an issue in other games.
Also, as you’d expect, ability/skill checks can become rather predictable. This isn’t to everyone’s tastes, of course, but for us it’s a feature rather than a bug. Outliers can still happen, and to add a bit of further uncertainty to the process, we’ve given results of 3-5 and 16-18 special outcomes (with 3 and 18 being particularly dramatic).
As many of you have pointed out, it would be easy to dial the bell curviness up or down by using 2d10 or 4d4 or whatever. I think 3d6 works well for us, but I would be interested to hear of anyone using something else.
And if anyone has used something other than 1d20 at higher levels I’d be very interested to hear what they have to say.