Placing an area of cube

[Gaulin]

A very niche question that I can't find the answer to - how would one place an effect with the area of a cube? Specifically looking at hell of a million needles, which says you place a cube which is 30ft on a side. Cubes aren't defined, as far as I can see, in the rules as far as placing them. I assume you could cast ho1mn in a hallway or the like. Common sense would say the center of the cube would be the origin point of the effect, so you could put that point against a wall and have the effect go 15ft out, but I'm hoping there's a more solid and RAW answer somewhere I can't find.

[The Raven Black]

"a cube 30 feet on a side within 500 feet"

I read it as meaning you can put the cube anywhere as long as it does not go beyond the 500 feet distance.

Also "When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect's area, or the place where you create something with a spell or other ability. This is called a line of effect."

Not sure this answers your question though.

[Baarogue]

A cube 30' on each side is 6x6x6 squares, the center of which will be an intersection 3 squares from any edge. If what you're asking is how to place such a cube in a hallway or other room it would not fit in; I would simply choose the intersection, then fill out the space as well as possible. That's what we do with fireball, which is a sphere

[Gaulin]

Yeah I'm having a hard time describing what I mean, but I think the crux of it is - where if the origin point of the spells area. If one was fighting enemies in a 25 x 25 ft room, could you place the 'origin point' of the spell against one of the walls, hitting enemies 15ft away from that wall and leaving the other 10ft free of the needles? Logically, that's kind of the only way I can picture it working outside of the too bad to be true (hopefully) of the impulse needing a full 30ft x 30ft space to be able to manifest.

Edit - Yeah a fireball (burst) is kind of what I'm assuming how the cube works. I guess I was mostly just hoping for confirmation or an example of a cube effect that I hadn't been able to find.

[The Raven Black]

I would adjudicate that you can put the cube anywhere you want within the 500 feet distance as long as you have line of effect to one of its vertices. And then the effect only extends to areas within the line of effect, like the fireball example.

A bit as if it were a 30ft cone and you choose the origin point as you wish as long as the whole cube/cone stays within 500 feet.

[Ravingdork]

Seems like you understand how it works already (or at least how I think it works). Don't let self-doubt get in the way of your fun.

Go forth and impale your enemies in tiny rooms with your tiny needles with a big smile on your face.

[SuperParkourio]

I think inhaled poisons have similar problems. According to the inhaled trait, such a poison is activated by unleashing it in a "10-foot cube." Where's the point of origin? Doesn't say. How far can the point of origin be? Doesn't say.

If the point of origin is both a corner of your space and the center of the cube, then you cannot deploy the poison without poisoning yourself, so at least one of those things must be wrong.

[The Raven Black]

I think it is safe to assume the poison's cube is adjacent to where it is unleashed.

Though I guess it could include the square where it is unleashed if the poison user so wishes.

AFAICT there is no "point of origin" for a cube.