Placement of spells - centered on you (clarification needed)


Rules Questions

Dark Archive

8 people marked this as FAQ candidate.

I've had problems with Spells that state "centered on you" as part of the area (or effect) description.

Examples would include:

Antimagic Field (http://paizo.com/prd/spells/antimagicField.html)

Emergency Force Sphere (http://www.d20pfsrd.com/magic/all-spells/e/emergency-force-sphere)

Similar: Magic Circle against evil (http://paizo.com/prd/spells/magicCircleAgainstEvil.html)

From my understanding, all spells have a clearly defined shape.

Let us start with the Antimagic field as an example:
It states "Area 10-ft.-radius emanation, centered on you"

http://paizo.com/prd/magic.html:
An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell. Most emanations are cones or spheres.

http://paizo.com/pathfinderRPG/prd/image/SpellAreas.jpg

We now know what that shape should be, the big question for me is the placement. Nowhere in the chapter "magic" I could find an example of an area effecting spell NOT originating from a grid intersection. However we have the what seems to be more specific rule of "centered on you".

As the area is fix, a spell centered on a field would, from my perspective, have to influence 50% of certain fields. Something I do not know how to handle. This ruling gets even more bizarre when looking at Magic Circle against Evil:

"10-ft.-radius emanation from touched creature"

This spell does not include specific as to how to place the emanation on the creature (i.e. there is no "centered"). This however means, the general rules kick in, stating that emanation has to originate from a grid intersection.

It gets even more complicated when looking at Emergency Force Sphere. Considering that you would go with the "centered on you", that would mean you could under no circumstances cast the emergency force sphere in a 2x10 tunnel, as you cannot stand on a grid intersection. Instead you would need a 3x10 tunnel.

So my question would be: does "centered on you" mean, that I have to chose a specific grid intersection on me or what does that mean and how do you handle that in your games?

Grand Lodge

Choose a specific grid intersection at the centre of your space. If the centre of your space is a grid square (as it is for most PCs), pick one of its four corners.

edit: It looks to me as if emergency force sphere's 5' radius hemisphere centred on you places you in your choice of the four squares that the dome takes up.

Dark Archive

That is what I was thinking, however, a lot of people rule differently. I could also not find anything official (e.g. FAQ on this).

+ in that case an antimagic field would not make any sense on a dragon

Dark Archive

bump. I really would like to hear other opinions on this and maybe get an FAQ ;)


Quote:
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. -- Link to rule

Its also under the magic section under 'Aiming a Spell' subsection 'Area'.

Its because you 'fill' a 5'x5' cube. If a fireball was centered on the center of a square the edge squares would all only be 1/2 filled. Whose to say which 1/2 a bad guy was standing it. Would be be granted a cover bonus to reflex saves? Picking a grid intersection ends arguments about where you were in a square. Its a mechanic to make the game run easier.
-----
In a game I once ran I gave people an option to chose the center of their square and people in the 1/2 square on the edge of the radius could choose to be inside the affected area or outside it, no one ever chose to pick the center of their square.


looking at the templates online makes me laugh every time.....

if the spell is a 5' burst the template assumes Im standing on an intersection. I know things like "burst from you" are only flavor text but it never made much sense to me that I could send out a 5' burst that did not affect someone directly adjacent to me.

Assume a silly combat where Im completely surrounded by enemies:

x x x
x M x
x x x

I couldn't hit everyone with that 5' burst since Id need to pick a square so MAYBE could affect a few of them (in bold)

x x x
x M x
x x x

BUT if I had Whirlwind Attack in the same scenario they are all in reach so I could hit every one of them. Seems silly, I know, but in a game that uses squares and grids Im surprised that "5' radius spread from you" isn't the same as your 5' threat range with a melee weapon:

x x x
x M x
x x x

Dark Archive

The difference is, that the latter is not a 5' radius; it is denoted as "everything in reach"; a Paladin Aura that reads "every target within 5'" would have the same result and is entirely different to the templates for spells.

TL;DR: non-spell rules usually not speak of a radius but of "within X'"; spells give a specific radius for areas of effect

Please hit FAQ ;)


oh, I get the difference in how the rules are written.....I don't understand WHY they are written differently! FAQ already hit!!

Dark Archive

Indeed. That leads to a lot of confusion and I've seen GMs (also in PFS) rule both ways,

Lantern Lodge

What Splendor said: Its a mechanic to make the game run easier.

However, that's why the game has GMs. Sometimes a GM just has to rule on something and it may not be entirely RAW. For example, if you wanted to cast emergency force sphere, BUT there is for some reason no grid intersection that would allow a legal 5' radius force sphere under the Wall of Force rules about being continuous and unbroken, but there is in fact a legal 5' radius that doesn't align with the grid intersections, the GM can simply allow the PC to cast the spell centered off the grid intersections in the legal space available.


I agree that it is not spelled out explicitly in the rules, but I think it's fairly clear by extension that it should operate as Starglim says - you pick a grid intersection in your space as the origin of the spell. That's certainly how I run it in my games. Here are the relevant rules (all from the Area section of Aiming a Spell):

PRD wrote:
Regardless of the shape of the area, you select the point where the spell originates, but otherwise you don't control which creatures or objects the spell affects. The point of origin of a spell is always a grid intersection.
PRD wrote:
Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell's point of origin and measure its effect from that point.
PRD wrote:
An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell. Most emanations are cones or spheres.
PRD wrote:
A cone-shaped spell shoots away from you in a quarter-circle in the direction you designate. It starts from any corner of your square and widens out as it goes.
PRD wrote:
A line-shaped spell shoots away from you in a line in the direction you designate. It starts from any corner of your square and extends to the limit of its range or until it strikes a barrier that blocks line of effect.
PRD wrote:
A sphere-shaped spell expands from its point of origin to fill a spherical area. Spheres may be bursts, emanations, or spreads.

From these rules, we know that a spell's point of origin is always a grid intersection. (This is shown in the Spell Areas diagram just above this section of the rules - note that the red dot is the point of origin, not the position of the caster). The rules also state that you choose the point of origin. Furthermore, it's clear how a cone-shaped emanation originating from you (such as detect secret doors) works - you pick a corner of your square as the origin. It's also clear how a line-shaped emanation originating from you (such as gust of wind) works - you pick a corner of your square as the origin. All that remains is for us to work out how a sphere-shaped emanation (such as antimagic field) centred on you works. Based on all this information, I contend that you should pick a corner of your square as its origin.

Dark Archive

Captain Zoom wrote:

What Splendor said: Its a mechanic to make the game run easier.

However, that's why the game has GMs. Sometimes a GM just has to rule on something and it may not be entirely RAW. For example, if you wanted to cast emergency force sphere, BUT there is for some reason no grid intersection that would allow a legal 5' radius force sphere under the Wall of Force rules about being continuous and unbroken, but there is in fact a legal 5' radius that doesn't align with the grid intersections, the GM can simply allow the PC to cast the spell centered off the grid intersections in the legal space available.

Actually, the case that made me write this post was a GM that fumbled the emergency force sphere because I was in a 2x2 area and he ruled that as the sphere is centered on me it would take half a square of squares that were occupied.

Dark Archive

bump

Lantern Lodge

Chevalier83 wrote:
Actually, the case that made me write this post was a GM that fumbled the emergency force sphere because I was in a 2x2 area and he ruled that as the sphere is centered on me it would take half a square of squares that were occupied.

Sounds like your GM was abrogating his role and being slavishly pedantic about following rules. Bottom line, there was enough space for the sphere to appear, the grid intersection rule is a convenience that the GM can overrule when appropriate, and he should let you cast the spell. I'm all for GM's making rulings, but I reserve the right to point out when they're being silly.

Dark Archive

actually, he kinda plays all "centered on you" spells like that, so I could've known. That's also part of the reason why I'd love to see a FAQ.


1 person marked this as FAQ candidate. 1 person marked this as a favorite.

Yeah, I noticed this when looking through the bloodrager bloodlines. Abyssal gives you a 5ft aura centered on you that does 2d6 plus Con Mod fire damage to all creatures that end their turn in it. So by the current rules you would be damaging yourself every turn(even with the innate fire resist 10, a level 16 raging bloodrager will have close to a +10 con mod).

Community / Forums / Pathfinder / Pathfinder First Edition / Rules Questions / Placement of spells - centered on you (clarification needed) All Messageboards

Want to post a reply? Sign in.
Recent threads in Rules Questions