Can I cast spells with radius if there isn't enough space?

[Letric]

Glitterdust, Grease, Create Pit.

Those spells have a radius that is something like 10/20 radius.
Am I able to cast those spells in a 5 ft corridor for example?

Is there a specific spell for each case?

I'm asking this because the origin of the spell is usually an intersection of squares, and technically I'm only see 1/2 sides of that center of origin (information)

EDIT= links added for reference

[darth_gator]

Unless the spell description specifically tells you otherwise, yes, you may absolutely cast spells in areas smaller than the spell's size and shape.

Spells like glitterdust and grease will just fill up the squares that aren't blocked by the walls, e.g. grease fills a 10' square, so in a 5' wide corridor, you'll fill two squares with the grease (the remaining 2 squares will be "wasted").

Create pit specifically requires you to cast the spell in an area of sufficient size. So you can't cast it in a 5' wide corridor.

[Letric]

darth_gator wrote:

Unless the spell description specifically tells you otherwise, yes, you may absolutely cast spells in areas smaller than the spell's size and shape.

Spells like glitterdust and grease will just fill up the squares that aren't blocked by the walls, e.g. grease fills a 10' square, so in a 5' wide corridor, you'll fill two squares with the grease (the remaining 2 squares will be "wasted").

Create pit specifically requires you to cast the spell in an area of sufficient size. So you can't cast it in a 5' wide corridor.

Cool, nice! I wasn't sure about it. Double checked Create Pit, and you are right.

First time playing a Wizard, and some questions come as I use spells.

[Phoenix M]

2 squares aren't wasted, just don't lean on the wall for support it too has been greased. So many people fail to see the 3rd dimension in table top games. :)

[darth_gator]

Phoenix M wrote:

2 squares aren't wasted, just don't lean on the wall for support it too has been greased. So many people fail to see the 3rd dimension in table top games. :)

Nothing in RAW indicates you can cast grease with a right angle running through the center of its area of effect. So, while I personally would have no issue with a caster doing this, I don't think it fits RAW.

[Dragonchess Player]

You should review Aiming a Spell in the Magic chapter of the Core Rulebook. Glitterdust is a spread (detailed in the Magic chapter) and grease simply specifies "a solid surface" (no restriction on it being flat), however create pit has the restriction "You must create the pit on a horizontal surface of sufficient size."

[Letric]

Dragonchess Player wrote:

You should review Aiming a Spell in the Magic chapter of the Core Rulebook. Glitterdust is a spread (detailed in the Magic chapter) and grease simply specifies "a solid surface" (no restriction on it being flat), however create pit has the restriction "You must create the pit on a horizontal surface of sufficient size."

So burst means it spreads, but if it doesn't have any space on the 10 ft you don't get a 4 line glitterdust, right?

[Goddity]

In one of the earlier DnD editions, spell effects would compound if compressed. Fireball damage could be multiplied massively if you cast it in a corridor. Of course, it would also spread around the corridor, until it covered enough space, but thats irrelevant.

[Kazaan]

Well, in the case of a damaging spell like Fireball, it would attempt to damage things like walls, pillars, obstacles, etc. Spread effects like Glitterdust affect objects and walls would certainly be objects, so if the wall (or ceiling for that matter) are within the area of effect, they will be covered in craft herpes. Grease affects solid surfaces and, if the counter-argument is that the spell doesn't specifically allow the effect to turn at a 90 degree angle, that also means the spell doesn't specifically allow the effect to turn at any angle. But it would be ridiculous to presume that Grease must be cast upon a mirror-flat surface or that you cannot grease a set of stairs. Thus, it is more meaningful to say that the spell must, in some way, spell out that you can't affect a non-horizontal surface because can is built into the system by default.

[darth_gator]

Kazaan wrote:

Grease affects solid surfaces and, if the counter-argument is that the spell doesn't specifically allow the effect to turn at a 90 degree angle, that also means the spell doesn't specifically allow the effect to turn at any angle. But it would be ridiculous to presume that Grease must be cast upon a mirror-flat surface or that you cannot grease a set of stairs.

But dropping grease on a set of stairs doesn't require you to bend the area of affect; the grease coats the top of the steps only, not the kickplate at the front of each step. If it does coat the kickplate, you're going to lose around 6" of width for each step. So, with a 10" step, you're going to use 16" of grease. You had 120" to start with, so you're only going to get 7.5' x 10' on the stairs, and since we round down in PF, you only get 5' x 10'. I think we can agree that there's no intent in the rules to reduce the area greased when cast on steps, so the area of affect doesn't actually bend around the steps; it merely coats the step portion. Neither does it automatically bend 90 degrees perpendicularly to coat 5' of floor and 5' of wall per RAW. In actual practice, I can see very few situations arising where allowing the greased area to spread onto the wall would cause any problems at all, and if a player asked, I'd allow it. However, the OP wanted to know if he could cast the spell in the 5' wide corridor at all, which we both agree he can.

Dragonchess Player wrote:

Glitterdust is a spread (detailed in the Magic chapter)

Yes, glitterdust spreads into 4 squares in the 5' wide corridor, coating the floor, walls, and ceiling (provided it's no more than 10 or 20' high, depending on where the spell was centered).

Letric wrote:

So burst means it spreads, but if it doesn't have any space on the 10 ft you don't get a 4 line glitterdust, right?

Actually you will have a line of 4 squares with glitterdust, because it has a 10' radius which equates to a 20' diameter.

[Dragonchess Player]

Letric wrote:

Dragonchess Player wrote:

You should review Aiming a Spell in the Magic chapter of the Core Rulebook. Glitterdust is a spread (detailed in the Magic chapter) and grease simply specifies "a solid surface" (no restriction on it being flat), however create pit has the restriction "You must create the pit on a horizontal surface of sufficient size."

So burst means it spreads, but if it doesn't have any space on the 10 ft you don't get a 4 line glitterdust, right?

The other way around:

Core Rulebook wrote:

A spread spell extends out like a burst but can turn corners.

A burst must have a line of effect from the origin point. A spread does not, as long as there is a path for the effect to travel.

[Dragonchess Player]

darth_gator wrote:

Kazaan wrote:

Grease affects solid surfaces and, if the counter-argument is that the spell doesn't specifically allow the effect to turn at a 90 degree angle, that also means the spell doesn't specifically allow the effect to turn at any angle. But it would be ridiculous to presume that Grease must be cast upon a mirror-flat surface or that you cannot grease a set of stairs.

But dropping grease on a set of stairs doesn't require you to bend the area of affect; the grease coats the top of the steps only, not the kickplate at the front of each step. If it does coat the kickplate, you're going to lose around 6" of width for each step. So, with a 10" step, you're going to use 16" of grease. You had 120" to start with, so you're only going to get 7.5' x 10' on the stairs, and since we round down in PF, you only get 5' x 10'. I think we can agree that there's no intent in the rules to reduce the area greased when cast on steps, so the area of affect doesn't actually bend around the steps; it merely coats the step portion. Neither does it automatically bend 90 degrees perpendicularly to coat 5' of floor and 5' of wall per RAW.

Incorrect. By RAW, grease covers a surface 10 ft square ("A grease spell covers a solid surface with a layer of slippery grease"). That surface is the area; trying to remove the vertical portions of a set of stairs is what goes against the RAW.

[Casual Viking]

Really, I recommend reading the Magic chapter at some point. Even to experienced players.