Advantage and Disadvantage stacking

[StAlda]

Here are all my numbers rounded to the second place after the decimal point, from the spreadsheet:

Average of best of 2d20: 13.83
Average Improvement over 1d20: 3.33
Odds of critical: 9.75%
Crit odds improvement over 1d20: 4.75%

Average of best of 3d20: 15.49
Average Improvement over 1d20: 4.99
Average Improvement over 2d20: 1.66
Odds of critical: 14.26%
Crit odds improvement over 1d20: 9.26%
Crit odds improvement over 2d20: 4.51%

Average of best of 4d20: 16.48
Average Improvement over 1d20: 5.98
Average Improvement over 2d20: 2.66
Average Improvement over 3d20: 1.00
Odds of critical: 18.55%
Crit odds improvement over 1d20: 13.55%
Crit odds improvement over 2d20: 8.80%
Crit odds improvement over 3d20: 4.29%

I know this is an old thread, but this really struck me as a mechanic of advantage/disadvantage. I too am concerned with over use of adv/dis, but stacking them seems like a winner. Instead of saying you have advantage, say you gain one advantage die or you gain 1 disadvantage die. We add up flat bonuses all the time so this should be just as easy.

So Bless, for instance, could negate 1 disadvantage die, Bane negates 1 advantage die. Most Conditions(stunned, blinded, etc.) generally do not overlap so there shouldn't be to much adv/dis inflation from them. And most spells cause a Condition, so that should keep things in check.

Having said that, I do believe prone, among other conditions should have flat penalties.

 

[Warbringer]

Yeah, except the probabilities are discrete to 5% increments, or rather probability events across the d20 range not the d100 range, so they all drip up to nearest 5%.

 

[StAlda]

Yeah, except the probabilities are discrete to 5% increments, or rather probability events across the d20 range not the d100 range, so they all drip up to nearest 5%.

But over multiple rolls they flatten out into the percentages above. If it says you should get an 18.5 on 20 sided die, it just means half the time it is 18 and half 19. Percentages still work.

 

[Falling Icicle]

Without any kind of stacking for advantage, the result will be that alot of buffs end up being useless in alot of situations where they shouldn't be. For example, a monster that rages takes disadvantage on its attacks. In this situation, using a buff like invisibility becomes worthless, since all it does is give the attacker disadvantage and the raging ogre the party is fighting already has that, so being invisible doesn't help, even though it should. This, in turn, will encourage alot of metagaming when players decide which abilities/spells to use or not use in particular situations. Nobody wants to spend a spell and have it do nothing, after all.

I also understand why being able to roll 3+ dice would quickly get ridiculous. This is why I'm starting to dislike the advantage/disadvantage mechanic. I think I'd now prefer that they just go back to the "DM's best friend" rule, where favorable circumstances grant a +2 and unfavorable incur a -2 penalty. That was a simple, easy and well balanced rule that I don't remember anyone ever complaining about.

They can still keep rerolls for certain effects, of course. The problem is that when you make it a major mechanical element of the game, as they've done with advantage/disadvantage in 5e, it inevitably gets overused.