I'm considering taking the Fearsome Rune on a weapon, and have feats or other runes which impose a saving throw on a hit/crit. Does the fear effect get applied before the saving throw, or after?
That is to say, will the fear penalty to checks apply to all these saves I might impose on a crit?
When you critically hit with this weapon, the target becomes frightened 1.
This weapon is empowered with freezing ice. It deals an additional 1d6 cold damage on a successful Strike. On a critical hit, the target is also slowed 1 until the end of your next turn unless it succeeds at a DC 24 Fortitude save.
The focused power of your flurry threatens to overwhelm your opponent. When you target the same creature with two Strikes from your Flurry of Blows, you can try to stun the creature. If either Strike hits and deals damage, the target must succeed at a Fortitude save against your class DC or be stunned 1 (or stunned 3 on a critical failure). This is an incapacitation effect.
The target must succeed at a Fortitude save against your class DC or be slowed 1 until the end of your next turn.
Best Answer
It's unclear
I couldn't remember seeing a ruling on this, and that's no surprise as there is nothing in the Encounter Mode, Playing the Game: Encounters, Turns, nor Actions rules about simultaneous Effects. This issue reaches at least as far back as Pathfinder 1e's predecessor, D&D 3.5e.
There are generally two methods for resolving this
Addendum:
I did miss one option, which I have seen used but haven't come across a lot of formal community support for:
Ask your GM which they use, or request which ruling that you consider to be more fun play.