As it says in the title, since the gate points for critical fail/fail, fail/success and sucess/critical success are all exactly 10 apart, +10 will always move you up exactly one catagory
You are also forgetting to account for the lower edge. If you roll a total of 30 against a DC of 55, greater evasion will still call that a "failure" - in that case you are getting more than a +10.
You are also forgetting to account for the lower edge. If you roll a total of 30 against a DC of 55, greater evasion will still call that a "failure" - in that case you are getting more than a +10.
yeah but to achieve that you have to roll badly on a check that is impossible outside of a nat 20. With the math as tight as it is in pf2 I dont think that should ever happen.
It's totally possible to fail by more than 10, but I don't think the math allows for failure by more than 19.
I believe Paizo tried to set things up such that on a natural 20 roll, (even ignoring the special rules about a nat 20 & nat 1 increasing or decrease success level by 1) they wanted those rolls to always succeed or fail, so they set DCs so that no two equal levels PCs were likely to be more than 20 apart (except when comparing untrained skills to trained or better skills).
It shouldn't happen, but it could happen - such as character that somehow gets into a fight with something vastly higher level than themselves.
Likely because their GM asked them "are you sure?" about their previous action three times and they didn't take the hint.
~glares at Dan~
poor Dan, he will be missed
Trying to find a case where you can legitimately fail a save by more than 19 against something you're supposed to be fighting is hard, but its even harder since if you have a greater evasion ability, its on one of your strong saves.
I think if you decide not to improve the relevant stat and get debuffed, it might be possible? Like a level 15 ruffian rogue with 12 dex fighting an Ancient Red Dragon as campaign boss, could have a reflex save of +26, if the rogue crit fails against frightful presence they could be down to a +22 against a DC 42 breath weapon. That's not too crazy a scenario.
It's not a +10 because it doesn't change a failure into a success.
Evasion: Success-> Crit Success
Imp. Evasion: Crit Fail-> Fail; Fail-> half damage.
Unless it is a Basic save, this isn't the same as a success. For instance, Glitterdust is a Ref save. If you fail, you're still dazzled for 1 min. Resiliant Sphere, a failure means you're still trapped.
I'm sure there are other spells where a success is no damage, so half-damage for failure is worse or a spell where there is persistent damage on a failure but not a success.