The spell lists it as personal, meaning it draws a 5ft/lvl radius from only ever the caster, but it doesn't clarify if that radius is affected by LoE or cover.
Should the effect be a spread that just requires some line of effect, an emanation which is blocked by cover, or does it just always work regardless of anything else but distance to target and why?
To clarify, emanations are only blocked by total cover, not regular cover.
Line of Effect is also broken by total cover, in fact total cover is defined as breaking line of effect.
So your concept of "something else that requires line of effect" and an emanation are the same thing.
|
Most divinations have text saying they are blocked by this and that thickness of material or whatnot. Emanation, burst, cone, etc are normally listed in spell description as well. So by RAW, it reveals everything in the range and is blocked by nothing. In practice though, I generally see people running it as an emanation.
To clarify, not all divination spells specify this. It's not something that applies to all of them (although for home games I do have that rule for a lot of them, all of them except for spells that are locating something).
So that restriction would not apply here.
In general, I think running it as an emanation is the only sensible way to do it.
Just to be clear, invisibility purge is an evocation, not a divination. Most every evocation spell requires line of effect, unless they are a spread, so that would make the most sense. (Wow, the Evocation section of the Magic chapter is three short sentences, hilarious).
Is the "sphere of power" an emanation/burst or a spread? Are there any spreads that persist from a point, object, or creature? Only spread I can find that even targets an object or creature is shatter, and that's not persistent. Seems pretty likely it acts as an emanation (i.e. as a burst, not going around corners), and would need line of effect - at least a 1' square hole.
This does remind me of Frank Mentzer running 1e D&D with continual light working through walls, because it has a radius and does say anything about line of effect :)
@Claxon, yeah emanations don't get blocked by "cover" because it's assumed that it's not big enough to hide begins, therefore not total cover. Maybe if a mouse was invisible, it could gain total cover behind the vase and thus be excluded from the effect but that's because the level of cover isn't determined by the the ability to wrap around an object, just it's relative size.
@gnoams and Majuba, thanks for your inputs.
Majuba, good call on Invisibility Purge not being a divination.
I didn't even double check on that one.
@Claxon, yeah emanations don't get blocked by "cover" because it's assumed that it's not big enough to hide begins, therefore not total cover. Maybe if a mouse was invisible, it could gain total cover behind the vase and thus be excluded from the effect but that's because the level of cover isn't determined by the the ability to wrap around an object, just it's relative size.
@gnoams and Majuba, thanks for your inputs.
Kind of, yes.
But cover vs total cover can also be something like I'm behind a decorative wall with lots of holes (I don't know if a specific size is stated, but we know a fireball can be shot through a 1ft diameter hole but requires a check to be done) then it's not blocking line of effect sufficiently to stop the magic from affecting me.
Fair, although in the case I am unsure about, it's more of a solid, stone wall around a corner.
And in the case of a holey wall that you could also shoot a fireball through, I imagine streaks of a person becoming visible from thin lines of effect would also be enough to effectively give the invisibility away...
Around a corner assuming you're not right next to the corner (cause that can get weird and cause arguments) definitely grants you total cover (assuming the wall is a solid wall without significant openings).
Think of an emanation as drawing a straight line from a source point (which can be a character). If the line is blocked from reaching something, then it doesn't have line of effect. And thus the emanation is blocked.
The reason why being at the corner or a wall can be contentious is some people will argue it's total cover, other will save it's partial cover.
I say it's only partial cover, because you occupy the whole 5ft square and you can reach the far corner of the square completely uninterrupted.
Other will say "I'm pressing myself up against the wall so it doesn't count".
And you go from there.
Right, I know *how* emanations work, my confusion is "is invisibility purge an emanation or what". Not checking for edge case so much as confirming that it actually cares about cover at all like an emanation, just needs to be able to draw a nonstraight line shorter than 5*CL ft. but cannot go through cover as a spread, or if it's radius regardless of any obstructions.
|
|
So again. RAW, invisibility purge is blocked by nothing.
In the magic chapter of the crb: "Most spells that affect an area function as a burst, an emanation, or a spread." and "A burst, cone, cylinder, or emanation spell affects only an area, creature, or object to which it has line of effect from its origin."
Since invisibility purge is not like most spells as it does not say that is an emanation, then it is not subject to the restrictions of needing line of effect to work.
However, most people (in my experience) house rule it to function as an emanation, and have it be blocked by being on the other side of a wall or the like. This might simply be because most spells work according to the defined area types, so fitting this one into one of the definitions makes sense. It may be intentional that "emanation" was left off the spell in order for it to function through barriers.
Sorry to confuse with the divination stuff. I meant to draw correlation with other similar game effects, but yeah, that didn't come out well. My bad.