Confusion on Grazing Hits

[tkneip1874]

Lately I have had some confusion on grazing hits. I started to notice quite a few when doing Epic Elite quests so I farmed and got Legendary Ring of Prowess from Good Intentions. When I finally got ring I did not notice change. When I started looking in combat log then minimum attack bonus I had is just over 100. I also noticed that depending on what I rolled made more difference than total attack bonus. Example 3+116 = Grazing hit yet 13+106 = Hit. I should think that they should be the same. Anyone have any thoughts as to why this is?

[tkneip1874]

Sorry for giving this a bump but has no one noticed this?

[Wh070aa]

It probably depends on enemies AC bonus.

[Eth]

No, 3+116 and 13+106 are two entirely different things.

The second number is your attack bonus and is used in the to-hit formular, which determines the % chance of you hitting.
The dice roll (1d20) determines how much % chance you actually need for that attack to make a hit.


To-hit formular:
(Player’s Attack Bonus + 10.5) / (Target’s Armor Class * 2) + 20% proficiency bonus, rounded to nearest 5% (5% extra for precision and some of the racial elven stuff if you have it)

If you roll a 3 on the dice you need a higher than 85% to-hit on the formular to make it a hit.
On a roll of 13 you only need a higher than 35% chance.