Wert!'s page

The Core Rulebook?

Okay I found it!

A natural 20 increases the degree of success by 1, so for a 20 on the die:

crit fail -> fail
fail -> success
success -> crit success

In the case of an enemy with an AC of 19 and a nat 20 results in a value of let's say 17, (20-3), that would normally be a failure, but because it's a nat 20 it becomes a success.

Same thing with a nat 1
crit success -> success
success -> fail
fail -> crit fail

In the case where you roll a 1 with a mod of +11 against an AC of 11 that would normally be a success, but since it's a nat 1 it becomes one step worse: aka a fail. On the other hand, let's say you had a +21 to hit against an AC of 11, then a nat 1 would be a 22 against an AC of 11, which would normally be a crit success, but since it's a nat 1 it becomes a regular success instead.

Is there a Paizo ruling source I can find this?

If in battle an enemy has an AC of 19 and I Roll a 20 on the die with a negative modifier for a third attack is it consider a critical success still if the modifier drops it below 19. Also If I roll a 1 and my modifier of +11 on first attack lets say brings it above AC 11 of the creature, is that consider a hit not a critical failure. I thought 20 and 1 were still their respective critical success and Failure with the added 10 higher or 10 lower addition to rules?