D&D 5E Going for 3d6 instead of d20

[Horwath]

For next campaign, I'm considering going for 3d6 instead of d20 for all rolls.
As IMHO, biggest problem of any d20 system is the "d20".

Reasons: d20 is unrealistic probability chance considering skill of the "user".

It gives the same chance to perform on your average ability and on your worst or best possible(5% for everything)

3d6 gives a nice bell curve that peaks at average rolls, around 68% rolls are between 8 and 13, while on d20 there is only 30% to be in average rolls, and range of 5-15(what most DCs are based);
on 3d6 it is 93% chance vs. 55% chance on d20.

3d6 also fixes the issue of round the party "knowledge" checks, where 5 people roll and hope for 15+ as no one has any intelligence skills

with d20, rolling 15+ at least once in party of 5 is 83,2%. Very high for a party of mostly dumbarses.

With 3d6 that luck fest drops to 38,5%. Less than half than with d20.

Advantage rules are also simple:
Roll 5d6 drop 2 lowest. That is little bit lower on average than 2d20 drop lowest, but it gives more consistency.

Also 3d6 gives option to give "half advantage" on some checks that are easy for the player but not warrant full advantage(I.E. flanking), with 4d6, drop lowest(it given little less than +2 on the check)

As for critical hits to give again 5% chance(10/15% for champions)

Natural 20 on d20 would be natural 16-18 on 3d6, 5% vs. 4,63%

19-20 on d20 would be 15-18 on 3d6, 10% vs. 9,26%

18-20 on d20 would be 14-18 on 3d6, 15% vs. 16,20%


3d6 moves results from luck factor to skill factor, and players will try to find sources of advantage(or even half advantage with this variant) rather to count on lucky roll from multiple d20 rolls.

 

[rgoodbb]

Blasphemy! Heresy! Burn the Witch!

 

[Shiroiken]

Could work, but you'd need to rework base assumptions of DCs. Getting a 15 is MUCH harder with 3d6 than 1d20, so the base assumptions of the DCs would be way off. I would say the DCs should then range from 7-13, instead of 5-15. Also, expect combat to take much longer unless you modify AC (maybe base AC 7 instead of 10) and spell DCs (base 5+modifier?). Not sure if it would be worth the effort.

 

[Fanaelialae]

Personally, I don't mind the luck factor. Having something happen is more interesting to me than having nothing happen (admittedly there are other ways to make this happen, such as fail forward). Under this change, you may find that you need to hand out more proficiencies, since the odds are worse that a nonproficient character can succeed on an above average check. This will make having a high primary ability score more important, I think.

This will also mean that the highest a PC can roll is 2 points lower, meaning that high DCs (or ACs) may need to be tweaked. Have you considered using 2d10? It preserves the normal range (aside from 1 becoming 2) and has a 79% chance of falling within the 5-15 range.

 

[Horwath]

Could work, but you'd need to rework base assumptions of DCs. Getting a 15 is MUCH harder with 3d6 than 1d20, so the base assumptions of the DCs would be way off. I would say the DCs should then range from 7-13, instead of 5-15. Also, expect combat to take much longer unless you modify AC (maybe base AC 7 instead of 10) and spell DCs (base 5+modifier?). Not sure if it would be worth the effort.

hmm, combats could get faster as now hit rate is about 60-65%. 65% on d20 is 8+. 8+ roll on 3d6 is 83,8%. So, more hits, more damage per round, less rounds to go.

Even if hit rate is on roll of 10+(55%), roll 10+ on 3d6 is 62,5%. that is 13,6% more damage.

Only if there is 45% hit rate. d20 roll of 12+, there is reduction in damage, roll 12+ on 3d6 is 37,5%.

 

[Horwath]

Personally, I don't mind the luck factor. Having something happen is more interesting to me than having nothing happen (admittedly there are other ways to make this happen, such as fail forward). Under this change, you may find that you need to hand out more proficiencies, since the odds are worse that a nonproficient character can succeed on an above average check. This will make having a high primary ability score more important, I think.

This will also mean that the highest a PC can roll is 2 points lower, meaning that high DCs (or ACs) may need to be tweaked. Have you considered using 2d10? It preserves the normal range (aside from 1 becoming 2) and has a 79% chance of falling within the 5-15 range.

2d10 is my second option. But 3d6 has the same average as d20(10,5). On 2d10 is 11. Maybe then I could make all base DC's 9 instead of 8. And passives would be 11+modifiers.
But I really like the d6 die. And d12.


Yes, hitting high AC would be harder with 3d6, but it would force players to think about ways of getting advantage. And I already stated that some circumstances(flanking) would give "half advantage" 4d6, drop lowest.

Also I consider that any roll on d20 of 16+ should be luck and rare, not 25% chance.

 

[Fanaelialae]

2d10 is my second option. But 3d6 has the same average as d20(10,5). On 2d10 is 11. Maybe then I could make all base DC's 9 instead of 8. And passives would be 11+modifiers.
But I really like the d6 die. And d12.


Yes, hitting high AC would be harder with 3d6, but it would force players to think about ways of getting advantage. And I already stated that some circumstances(flanking) would give "half advantage" 4d6, drop lowest.

Fair enough, though you could do a half advantage with 2d10 also (3d10). I don't feel that changing the average from 10.5 to 11 makes enough of a difference to matter. The typical average DC is 10 rather than 11.

Also I consider that any roll on d20 of 16+ should be luck and rare, not 25% chance.

It's 15% actually, far from common (same odds as rolling 18+ on a d20, which always feels lucky to me).

 

[Horwath]

Fair enough, though you could do a half advantage with 2d10 also (3d10). I don't feel that changing the average from 10.5 to 11 makes enough of a difference to matter. The typical average DC is 10 rather than 11.

advantage with 2d10 would be 3d10 drop lowest. 4d10 drop 2 lowest is too much.

 

[Quartz]

You might also consider 6d4-4 or 4d6-4. If you were cruel, you could use 3d8-4.

 

[CheezyRamen]

With more hits per round I think the survival rate should plummet. For lower level sessions I think it would be a rather large learning curve.