Your reactions let you respond immediately to what’s happening around you. The GM determines whether you can use reactions before your first turn begins, depending on the situation in which the encounter happens.
Once your first turn begins, you gain your actions and reaction. You can use 1 reaction per round. You can use a reaction on anyone’s turn (including your own), but only when its trigger occurs. If you don’t use your reaction, you lose it at the start of your next turn, though you typically then gain a reaction at the start of that turn.
Guess it depends on how nice the GM wants to be prior to the start of your turn on the 1st round of combat. Probably the only time it wouldn’t happen is the rare surprise attack round in PF2E
When I GM, I may allow players to prepare a reaction to a specific trigger in an ambush situation (potentially the same for my monsters). For example, say a party is hiding in a room, and they know that a guard will be coming by to check the room in 10 minutes. They have ample time to choose their hiding positions behind cover, and perhaps the players have decided to react in certain ways on various triggers on the guard entering (such as closing the door behind the guard, or backstabbing if the guard walks unaware in front of them, etc).
Typically, I would only allow for one reaction before initiative is rolled, and only in a situation where the ambushing party’s stealth checks all surpassed the Perception DC of the ambushed party. However, once the reaction is used, then all parties are aware of each other and initiative must be rolled. All of the other untriggered reactions become moot, and they just have to live with that (screw you players!).
I dislike that surprise rounds were nixed, and this is my very basic and situational work-around.
So um… the Seek action. Apparently I/we have been doing it wrong since 2019 in regards to hidden objects. In the old CRB it was a 30 foot cone or a 15 burst (within line of sight) to find hidden creatures, but to detect hidden objects (like traps) the seeker could only do a 10 foot square adjacent to them.
Welp, this is Seek in the new player core:
You scan an area for signs of creatures or objects, possibly including secret doors or hazards. Choose an area to scan. The GM determines the area you can scan with one Seek action—almost always 30 feet or less in any dimension. The GM might impose a penalty if you search far away from you or adjust the number of actions it takes to Seek a particularly cluttered area.
The GM attempts a single secret Perception check for you and compares the result to the Stealth DCs of any undetected or hidden creatures in the area, or the DC to detect each object in the area (as determined by the GM or by someone Concealing the Object). A creature you detect might remain hidden, rather than becoming observed, if you’re using an imprecise sense or if an effect (such as invisibility) prevents the subject from being observed.
Critical Success Any undetected or hidden creature you critically succeeded against becomes observed by you.
You learn the location of objects in the area you critically succeeded against. Success Any undetected creature you succeeded against becomes hidden from you instead of undetected, and any hidden creature you succeeded against becomes observed by you. You learn the location of any object or get a clue to its whereabouts, as determined by the GM.
So last night I learned I’ve been doing the order of operations of Lingering Composition wrong - at least in my head - for the entire existence of PF2. Probably 'cause I’ve never actually read Lingering Composition.
In my head:
cast “song”
make it linger ('cause you have to, you have, you have to let it linger)
@Rando and I had a conversation about the warpriest doctrine for clerics the other day and I was under the mistaken impression that if you picked it over the cloistered cleric doctrine then you could choose strength as your key attribute - much like how a scoundrel rogue can choose charisma or a ruffian rogue can choose strength, or a fighter can choose either strength or dexterity, or a monk can choose strength or dexterity.
Apparently that’s not the case though even though wisdom is used for jack-squat in the remaster.
All I can say is that, despite the seeming internal inconsistency of how different subclasses are handled, it’s 100% consistent with how Paizo handles casters vs martials.
