Walls / Blade Barrier / Shapeable spells FAQ


Rules Questions


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FAQ question:

How do spells without a defined area (such as blade barrier) interact with a combat grid? Looking back on this question it has been asked over and over on the forums from the very beginning of Pathfinder. Please support this FAQ.

Detail: As the combat grid is an optional (but heavily used) part of the game we have rules for how area effect spells (line, cone, spread) work with the grid and rules for determining which squares they inhabit. When casting fireball we can (from the point of origin) get a perfect grid layout of where it is and every square within it's area is considered 'affected' by the spell.

Spells such as blade barrier or even shape-able spells may or may not act the same way - using blade barrier as the example:

One viewpoint: The spell uses intersecting grid points to define the wall and the wall is drawn along the gridline as per this line in the rules:

"The point of origin of a spell is always a grid intersection. When determining whether a given creature is within the area of a spell, count out the distance from the point of origin in squares just as you do when moving a character or when determining the range for a ranged attack. The only difference is that instead of counting from the center of one square to the center of the next, you count from intersection to intersection."

Opposing viewpoint: These rules are for area effect spells and don't apply to a spell such as blade barrier because it has a custom effect description which doesn't specify this interaction. The spell also states that you can create the barrier on top of a creature which then gets a save and must 'choose a side'.

If using the grid interaction this offensive use of the spell (and others like it) is worthless - also the spell has no width meaning that if it's created on a grid line there is no good rule interaction for if both sides of the barrier are considered 'affected' or if neither are.

The Exchange Owner - D20 Hobbies

I'd look at how Emergency Force Sphere is adjudicated.

Developers have said it's 4 squares.

Grid seems to be on Area spells.

You can sort much of this out via examining the spell effect/area rules. Effect doesn't mention grid and other spell formats do mention grid.


I'd like an official ruling as well.


James Risner wrote:

I'd look at how Emergency Force Sphere is adjudicated.

Developers have said it's 4 squares.

Grid seems to be on Area spells.

You can sort much of this out via examining the spell effect/area rules. Effect doesn't mention grid and other spell formats do mention grid.

Yep - there *is* disagreement though and a search of the matter shows that this has actually gone back to the origin of the pathfinder playtest. Given a decade of various forms of this question being asked, I think it's worthy of a FAQ.

Not all FAQ's have to dramatically impact the game (I don't think this one would either way honestly) but they should resolve questions that pop up commonly (that's part of the definition - thus 'frequently asked').


This discussion regarding aspects of this issue came to a nice resolution, but clarification from the Paizo team would be much better than a repeat of the same discussion in the future.

Sovereign Court

Pathfinder Starfinder Society Subscriber

I don't think putting blade barrier on a gridline means it affects both adjacent squares. The caster would pick a side to affect.


KingOfAnything wrote:
I don't think putting blade barrier on a gridline means it affects both adjacent squares. The caster would pick a side to affect.

I don't even think the caster could pick a side it effects. As it is a vertical effect and doesn't state a width, it would only give cover and effect anyone trying to pass through it.

Scarab Sages

I posted this in the other thread, but here's the shorter version. In order for blade barrier to affect a creature, it has to pass through that creature's space. A blade barrier on the grid line between two squares does not pass through either of those squares. So a medium creature in either square would not have to make a saving throw and would not be affected unless they step through the blade barrier. As someone pointed out in that thread, a large creature that's space includes both sides of the blade barrier would be affected by it, and would have to make a saving throw.

There are definitely situations where you might want to do that. If you as the caster are on one side of the barrier, it guarantees you keep creatures on the other side of the barrier, which means they have a cover penalty to hit you and have to take damage if they want to step through. If you drop it on them, and they make their save, they can choose to be on your side of the barrier and attack you without cover.


Koi Eokei wrote:
This discussion regarding aspects of this issue came to a nice resolution, but clarification from the Paizo team would be much better than a repeat of the same discussion in the future.

What happens is sometimes (even for those of us that like to play devils advocate) people realize that they aren't getting anywhere with an argument.

The solution isn't resolved due to that thread - it just resolved me to request a decent FAQ for it because frankly 'grid' is an optional part of the game and I disagree that if we play without one I can say 'I place my blade barrier on top of the medium sized creature' and if we play with a grid I can't.

That is a bad rule, and deserves an answer as to spell effects or spell language is wrong.

My guess on the resolution will be it's that custom spell effects don't follow the grid rule - not because I think I'm 'more right' but because it's the solution that requires no change to any text in the rulebook and 99% of the time they try to change as few words as possible because layout changes can alter page numbers and they refer to page numbers in printed content - etc. etc. etc.


Ckorik wrote:

What happens is sometimes (even for those of us that like to play devils advocate) people realize that they aren't getting anywhere with an argument.

The solution isn't resolved due to that thread - it just resolved me to request a decent FAQ for it because frankly 'grid' is an optional part of the game and I disagree that if we play without one I can say 'I place my blade barrier on top of the medium sized creature' and if we play with a grid I can't.

There's a middle ground between complete free-form placement and gridline placement, and it's a method used by some specific area spells: place both ends on a grid intersection and draw a straight line between them.

Such a line doesn't have to be orthogonal with regard to the grid so it can intersect squares and affect creatures in them.


Walls bisecting squares would have similar language. It doesn't need to be a drastic change. Even if its just a few clarifying words.


Bump for FAQ.

Sovereign Court

Pathfinder Starfinder Society Subscriber
Koi Eokei wrote:
KingOfAnything wrote:
I don't think putting blade barrier on a gridline means it affects both adjacent squares. The caster would pick a side to affect.
I don't even think the caster could pick a side it effects. As it is a vertical effect and doesn't state a width, it would only give cover and effect anyone trying to pass through it.

Is there a meaningful difference between "on a gridline" and "infinitesimally to one side of the gridline"?


Dude, King, that was my whole argument it that other thread. There is definitely a difference, but no one was hearing it then. Lol.

I was using "line" and area rules for my argument, and that didn't blow over well, because it's an effect.

IF IT DID HAVE SIMILAR VERBAGE TO LINE EFFECTS, THEN YES, you have to pick the side it effects. Since it doesn't, you're supposed to just put it wherever you want and if it goes through the corner of my square, then I just argue, well my small sized character isn't close enough to that corner to be effected.

Sovereign Court

Pathfinder Starfinder Society Subscriber

I don't know what you were arguing against in JDLPF's comment, but referencing line rules was not the way to go about it. You definitely confused things. What were you objecting to? It would have helped a lot if you had quoted something.

You only pick a side to affect if you do the easy thing and draw the wall down a gridline. You can get more creative with diagonals and such, but they just make a headache.


I honestly think spells with an effect (like walls) should originate in a corner or middle of one side, just for clear drawing purposes so you know what's effected. If blade barrier just down a gridline, or infinitesimally to one side, it would hold the same effect where it would only grant cover or cause issues if directly interacted with.

Sure its in my square, but like flaming sphere, make your save, declare which "side" you on within your square, and go about your day.


Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Roleplaying Game Subscriber

FAQ'd.

I've seen it come up enough times to warrant space in the online FAQ.

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