# What is the critical failure threshold?

Pathfinder 2e has, what I consider to be, a fun mechanic that that rolling 10 over or under the DC causes critical success or failure (or turns failure to success and vice versa). It came up recently that my group might be misreading the actual text to be literally how I summarized it here. The actual rules text for Determine the Degree of Success is

You critically succeed at a check when the check's result meets or exceeds the DC by 10 or more. If the check is an attack roll, this is sometimes called a critical hit. You can also critically fail a check. The rules for critical failure—sometimes called a fumble—are the same as those for a critical success, but in the other direction: if you fail a check by 10 or more, that's a critical failure.

For an example DC 30, we have been calling 20's critical failures. However, rereading the rules, it occurs that it might make more sense to consider 10 under the failure 'DC' of 29 (so a 19 is a critical failure) to be correct. Which is it?

# You've been doing it right

A Critical Failure happens when your total check is 10 or less than the DC.

## Language Analysis

Let's say you are going for a DC 30 check. You get a 29 total. You failed the check by 1. Similarly, a 28 fails the check by 2. Keep on counting down and you'll see that a 20 total is when you fail by 10 or more for the first time, resulting in a Critical Failure. Failing by zero is the same as succeeding by zero, and means you rolled the DC exactly. So it feels a little asymmetrical (there's 10 steps for simple Success because of the exact DC case, 9 for simple Failure), but this is how the rules are written, and the way that makes the most intuitive sense.

## Example of Paizo using more clear language

The language in that section is ambiguous, but Paizo went really in depth on it in a blog post on the mechanic for the playtest, and there's no indication that it changed. This quote from the blog post makes it more clear:

If your result was 10 or more lower than the target DC, or if you rolled a natural 1 and didn't meet the target DC, then you critically failed.

• Further (and present) confirmation can be found in the Earn Income Calculator (which as far as I can tell is the most 'authoritative' dice roller for pf2e by virtue of being on 2e.aonprd.com). Tbh I'm still annoyed by the asymmetry, but I had to give in when I saw for myself that even the calculator counts a roll of DC-10 as a crit fail.
– Ruse
Dec 1, 2022 at 4:19
• @Ruse this is also how the Foundry VTT system implements it, which, while not developed by Paizo, does officially work with them. I can't find an example in the rules that doesn't use the "fail a check" language, though, instead of the "10 less than DC " language.
– ESCE
Dec 1, 2022 at 4:23