D&D 3.5 - Using cloud kill in an uncharted maze

[Harlot]

Yo wise people, I need your verdict on this, please.

I'm DM'ing a game in which the players are currently in a 'Tuckers Cobolds' sort of maze. The corridors they walk are often connected through small, narrow passages only passable by small or smaller creatures (3 feet high). So the critters living there will run out from a small passage, throw stuff at the players, and the enter another small passage which most of the players can't physically enter. Lots of fun.

Now, the wizard, frustrated with the annoying critters attacking them hit'n'run style through these small corridors, decided to cast cloudkill into a corridor, having no idea how long it was, where it ends and whether it branches off or not. He fired it into uncharted territory, but in a direction seemingly leading towards sections of the maze not yet discovered.

Problem is, with his caster level, the cloud would move away from him at 10 ft./round, = 220 feet overall (according to the player, didn't check up on that. He's a level 10 wild mage).
The narrow corridor splits at a t-section after just 60 ft, and these two corridors branches off after another 40-50 feet, and then one of these corridors end in a cavernous cave while another corridor actually leads right back to where the group was standing.

Now here's the issue:
The PC casting it argued that the cloud would simply fill up all of the corridors from his starting point and EVERY passage connected to the starting point 220 ft. from there.
I argued that it moves as cloud, doesn't split at intersections, and thus rolled for the cloud going right or left at every intersection.

Was I right to do so? How would you rule it?

Also: The corridors were actually empty, but as he couldn't see them, he didn't know.
However, if they hadn't been, wouldn't the creatures in them be able to spot the cloud coming at them, and run from it? After all it moves very slowly...

As always, thank you for helping!
/Harlot

[Mr Adventurer]

The spell area would not increase. Creatures would be able to move away if they saw it coming, could mobe quickly enough, and had somewhere to go.

[Harlot]

Sorry, what do you mean 'the spell area would not increase?' (I assume it means that the PC is not right in his assumption?)
- The cloud moves down the corridor - so how do you/would you determine which way it moves?

[prufock]

Point 1: "Effect: Cloud spreads in 20-ft. radius, 20 ft. high"

Point 2: "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."

Point 3: "A spread spell spreads out like a burst but can turn corners. You select the point of origin, and the spell spreads out a given distance in all directions. Figure the area the spell effect fills by taking into account any turns the spell effect takes."

So it could split and go down 2 different corridors, but the effect can't cover more than 20' radius from a single point of origin. In effect, the split in the corridor would work the same as if there was a large room with a column in it. The column takes up space within the spell's effect, and one end of the spell's area to the other can't be more than 40' apart.

It would be much more effective to send it off down a single route.

[Fouredged Sword]

Couple of important lines here. Underlines added for clarity and emphasis.


Effect: Cloud spreads in 20-ft. radius, 20 ft. high


Unlike a fog cloud, the cloudkill moves away from you at 10 feet per round, rolling along the surface of the ground.


A spread spell spreads out like a burst but can turn corners. You select the point of origin, and the spell spreads out a given distance in all directions. Figure the area the spell effect fills by taking into account any turns the spell effect takes.

Ok, so the wizard casts cloud kill. He picks a point up to medium range away, and suddenly a cloud forms. It will penetrate the tunnels up to 20ft, importantly it follows the path of movement, not a set radius, so it is likely to have to turn corners and such for much less reach.

Now, the cloud is a spread from a set point. That point is what moves. The cloud simply follows that path. It will take whatever branch the wizard accidentally pointed it down. I would as him if he pointed it left or right, and if he shrugs flip a coin.

[prufock]

Ok, so the wizard casts cloud kill. He picks a point up to medium range away, and suddenly a cloud forms. It will penetrate the tunnels up to 20ft, importantly it follows the path of movement, not a set radius, so it is likely to have to turn corners and such for much less reach.

Now, the cloud is a spread from a set point. That point is what moves. The cloud simply follows that path. It will take whatever branch the wizard accidentally pointed it down. I would as him if he pointed it left or right, and if he shrugs flip a coin.

This is exactly it. To elucidate, here is a (poor) diagram.

http://i60.tinypic.com/oh0avs.jpg

In part 1, wizard casts cloudkill in a 20' wide hallway. The green sections show its effect, grey shows walls blocking the effect. The dot in the middle is the point of origin. As it gets to the T intersection in part 2, the radius of the effect is the same (20'). The point or origin can go left or right, but it can't split, nor does the unaffected portion behind walls get redistributed to make it wider. The radius remains 20'.

[Harlot]

This is exactly it. To elucidate, here is a (poor) diagram.

http://i60.tinypic.com/oh0avs.jpg

In part 1, wizard casts cloudkill in a 20' wide hallway. The green sections show its effect, grey shows walls blocking the effect. The dot in the middle is the point of origin. As it gets to the T intersection in part 2, the radius of the effect is the same (20'). The point or origin can go left or right, but it can't split, nor does the unaffected portion behind walls get redistributed to make it wider. The radius remains 20'.

Thank you all for your aid. The illustration was exceedingly helpful!

It makes sense with the point of origin
1) not splitting
2) being the center of the cloud as it moves
(So far I'm right - I love being right.)

My dilemma is this though: The wizard places the cloud in a corridor going straight north, so he points nothwards. The cloud moves 60 ft. northwards and then the corridor splits, one corridor going east, the other going west - and both corridors split again after that.
So if he pointed north, and the corridor then takes another direction, how do we determine which way it goes? Is it OK to just roll for it/flip a coin?
Or does the cloud simply stop at the wall because the wizard has implied no other direction?

[Harlot]

Btw, that same player said his breath weapon, a cone, would become a straight line (thus much longer) when fired into a corridor? The logic being that the walls would press it together, elongating it?
I ruled no, as breath weapons are either cone or line, and physics dont apply. True?

[Fouredged Sword]

The cloud will attempt to move directly away from the wizard. A wizard is standing facing north in a hall with two 90 turns at a dead end to the north (one east, one west). Those turns soon become cross intersections with a branch in each cardinal direction.. At the first 90 degree bend, it will take the direction opposite the side of the hall the wizard is standing on to move away from him in the most efficient manner. For the next turn, it will turn north again, as that is the direction most away from the wizard.

Odd little rules -
A wizard can herd a cloudkill by moving around it after it has been cast.

A cloudkill can be captured in a teacup by putting the saucer on top(had a wizard do just this to a cloud of fog at one point)

[darksolitaire]

Btw, that same player said his breath weapon, a cone, would become a straight line (thus much longer) when fired into a corridor? The logic being that the walls would press it together, elongating it?
I ruled no, as breath weapons are either cone or line, and physics dont apply. True?

I'd agree. Corridor's walls would take damage from breath weapon if applicable.

[Fouredged Sword]

Yes, the walls get spattered with acid/fire/ice, but the area does not extend unless the user uses the shape metabreath feat.

There is no way to cause an effect to exceed the space listed in it's entry. You can restrict it further, but you cannot extend it without modifying the effect itself.

[Psyren]

I'm DM'ing a game in which the players are currently in a 'Tuckers Cobolds' sort of maze. The corridors they walk are often connected through small, narrow passages only passable by small or smaller creatures (3 feet high). So the critters living there will run out from a small passage, throw stuff at the players, and the enter another small passage which most of the players can't physically enter. Lots of fun.

Sounds like it's not so much fun for the players if they're getting frustrated :smalltongue:

Still, if your caster is high enough for cloudkill he has lots of options. He can defend the party from whatever the kobolds are throwing, he can send earth elementals or allips after them, he can turn the fighter gaseous and have him chase them through the tiny passages they are using, he can polymorph the party to burrow through the maze, he can ready an action to glitterdust or resilient sphere them when they appear etc.

[Fouredged Sword]

Yeah, he should send earth elementals to drag them into the walls. Now, the cloud kill WILL do a lot of damage to the Kobolds. Any that are waiting around corners along the path of the cloud are dead, no save. They notice the cloud when it wraps around the corner they are hiding behind and kills them. All those blind turns are suddenly a really big weakness when it comes to avoiding the spell.

[Harlot]

Sounds like it's not so much fun for the players if they're getting frustrated :smalltongue:

Harassing the players is pretty much the point with Tuckers, right? :smallbiggrin:

Anyway, thank you all for fast replies - I heart this community! You're all awesome!

[Jeff the Green]

This is exactly it. To elucidate, here is a (poor) diagram.

http://i60.tinypic.com/oh0avs.jpg

In part 1, wizard casts cloudkill in a 20' wide hallway. The green sections show its effect, grey shows walls blocking the effect. The dot in the middle is the point of origin. As it gets to the T intersection in part 2, the radius of the effect is the same (20'). The point or origin can go left or right, but it can't split, nor does the unaffected portion behind walls get redistributed to make it wider. The radius remains 20'.

That's not quite accurate. A spread has to turn corners, so the area will look more like this:
http://oi59.tinypic.com/2d2awky.jpg
The green and blue areas are the effect and the red is not.

[Psyren]

Harassing the players is pretty much the point with Tuckers, right? :smallbiggrin:

Indeed - though again, your player isn't wizarding very well if Tuckers are a problem at 10th level. Again, I don't know what they're chucking at the party, but I'm willing to bet it won't get through a wind wall or wall of force for instance.

[Harlot]

Nah, they don't do much damage - the wiz was pissed off because evil DM let an opponent hurl Dust of sneezing and choking at him ...

[Psyren]

Shouldn't that affect the kobold too? It's not a grenade, you have to throw the powder into the air and it's a 20ft. spread.

[Urpriest]

I don't think there's any provision for the cloud turning. Its point of origin should just start entering the wall, especially since you only need line of effect at time of casting.

[Psyren]

I wonder what it would do at a Y-shaped junction instead of a T-shaped one?

[Arc_knight25]

You also need to take into account Inclines within the dungeon since Cloudkill is heavier then air. If it goes down an incline then it will have to keep going down that path regardless of which direction the wizard is facing. Also if you want you could have the fog sink through a pit trap so that the wizard will think the spell wasn't a complete waste.

The number of Kobalds that can be in this dungeon is almost unlimited so, place a few dead kobalds at the blind corners since they didn't see the slow moving cloud coming. It gives the player some satisfaction and it really doesn't change anything.

[Psyren]

The number of Kobalds that can be in this dungeon is almost unlimited so, place a few dead kobalds at the blind corners since they didn't see the slow moving cloud coming. It gives the player some satisfaction and it really doesn't change anything.

Excellent suggestion - and since it's 3.5 you might not even have to award XP for them.