What it means to "enter"

[SuperParkourio]

This section of GM Core says:

Aquatic Combat wrote:

As with flight, dispelling can be deadly if someone relies on magic to breathe underwater. It's generally best to avoid having enemies who can breathe underwater dispelling the water-breathing magic aiding PCs. Though PCs might be able to use air bubble and quickly cast water breathing again, having this happen repeatedly can be frustrating, and being forced to prepare an extremely high-level water breathing spell to avoid it isn't much fun either.

The trigger for Air Bubble is "A creature within range enters an environment where it can't breathe." I wasn't aware that the environment becoming unbreatheable counted. Is this what it means to enter something? If a dragon flies toward me, does that mean I entered its Frightful Presence? If a cinder rat approaches me, did I enter its Fetid Fumes?

[Errenor]

Just don't become too wrapped up in this. If you do, then when going around a corner and seeing your ally drowning you won't be able to do anything. She didn't enter 'environment where she can't breathe', she was already there. So no luck for Air Bubble.

[Claxon]

It does present an issue, that the word entering is being used inconsistently. By interpreting a dispelled water breathing spell to count as entering, it makes other things that use the word entering come into question.

I think the real answer here is the trigger should probably be changed. Maybe "a creature within range is not able to breath normally".

[Super Zero]

Making it a reaction is often more generous, but being unable to use it if you missed the trigger is awkward.

Something like "reaction when... or one action" would probably work better.

[SuperParkourio]

So if a dragon Flies right up to me and stays in melee, I don't have to worry about Frightful Presence because I never entered the aura?

[Finoan]

That would be one of the questionable things regarding the word 'entering' that you are going to run into if you become too wrapped up in this. As Errenor and Claxon mentioned.

I work with programming languages - where an incorrect variable name or mixing up a constant will have disastrous consequences on the results that the program creates.

Pathfinder2e is not written in a programming language. Don't read it like it is.

[Claxon]

Finoan wrote:

That would be one of the questionable things regarding the word 'entering' that you are going to run into if you become too wrapped up in this. As Errenor and Claxon mentioned.

I work with programming languages - where an incorrect variable name or mixing up a constant will have disastrous consequences on the results that the program creates.

Pathfinder2e is not written in a programming language. Don't read it like it is.

I agree we shouldn't read it like a programming language, but we also shouldn't have multiple ways to interpret the word "entering" from various abilities.

If the "common sense" way an ability should be played conflicts with the way a trigger of "entering" is interpreted for other abilities then one of them should be changed.

If air bubble is meant to give you an ability to use your reaction anytime a creature isn't able to breath, which I think it's what it's supposed to do, using the word "entering" isn't appropriate.

Same for a dragon's frightful presence. If at anytime I'm within range of the dragon, I should be hit by frightful presence (and it already has a built in limitation that makes it so you can be affected only once per minute).

Ultimately we shouldn't use the word "entering" to mean things other than entering. If I enter a building, I'm presumably outside and go inside. If the building (in this case the dragons aura or the unbreathable air) moves such that I'm inside of it, it does really fit the normal definition of entering because it's not something I did.

[SuperParkourio]

There's also relative motion to consider. Imagine you are on top of a train. The train passes through an dragon's Frightful Presence. Did you enter the area? Suppose the train is off, but the dragon flies by. Did you enter the area? Is there any difference? My group also asked such questions in 5e, since one of the story arcs took place on a train. I cast cloud of daggers on a passenger seat. Will it stay still? Relative to whom? Will all the passengers behind us get cut up by the cloud of daggers? Will the cloud of daggers harmlessly pass them? Relative to whom? The earth? The caster? The cloud itself?

[Errenor]

Claxon wrote:

I agree we shouldn't read it like a programming language, but we also shouldn't have multiple ways to interpret the word "entering" from various abilities.

If the "common sense" way an ability should be played conflicts with the way a trigger of "entering" is interpreted for other abilities then one of them should be changed.

You are of course correct. But that doesn't change the fact that we have to deal with what we have. And the designers sadly don't always have great language 'discipline'.

SuperParkourio wrote:

There's also relative motion to consider.

The only way I see to get good results in this case is to allow effect's creator to determine relative to what it is. You can completely throw all (areal, continuous, on dynamic arenas) magic in trashcan if you wouldn't allow spellcasters to do that. Of course, only big things like planets or vehicles count.