Originally Posted by Stabbey
Originally Posted by fallenj
Kind of wonder where you get these percents at for advantage/disadvantage. I could be wrong but isn't the rule roll a additional d20 an high goes to advantage an low goes to disadvantage. If you have both it's nullified except for halflings that can reroll 1s.

If this is the case bless an the other spell will have more value than you say since the percent is not 100% accurate.

Statistical modeling is where understanding the effectiveness of Advantage/Disadvantage comes from.


The chances of rolling a 10 or greater on a D20 are 55%. Every single number has a 5% chance to come up with a single roll.
If you have disadvantage, where you roll two d20 and take the lower, the chances of rolling a 10 or greater drop to 30.3%
If you have advantage, the chances of rolling a 10 or greater increases to 79.8%.

If anything, the OP's use of 10% increase for advantage is understating things.

Thanks Stabbey. I love to use the “dumb” math philosophy in DnD to simplify it.

Every +2 = 10%
Advantage as +4 = +20%.

Then why is it advantage bad for spell effectiveness if it’s an absolute increase of +20%? Because the impact of increasing 10% when you have 55% to hit is greater than a +10% over 75% basis smile it was explained in the main thread but here it goes again.

I’ve used bless average as a 2 but in fact is 2,5. That was done to simplify the calculation. Would that be a 2,5 the impact would be even greater.