Some people just want to watch the world burn.

[Mauve Shirt]

My DM had put me in the position of needing to burn down a giant stone fortress. Anyone know of a thermite spell in Pathfinder?

[Darrin]

My DM had put me in the position of needing to burn down a giant stone fortress. Anyone know of a thermite spell in Pathfinder?

Not all that familiar with Pathfinder, but if 3.x sources are still allowed:

Rockburst (Shining South, Clr 3, Dru 2, Sor/Wiz 3). Unattended stone object with at least 8 cubic feet explodes. (If the fortress is considered as attended, then just cast this on the continental plate underneath the fortress, and that should work just as well.)

Suspension (Shining South, Sor/Wiz 4). Levitate any nonliving object up to 1000 lbs/CL. Push these stone blocks over the fortress, then dismiss the spell. Assuming each object is at least 4000 lbs, anything underneath takes 20d6 falling object damage. Since the duration lasts days, you can set up dozens of these objects above the fortress, then drop them all at once.

[cerin616]

Stone to flesh. fireball.

[Grommen]

Stone to flesh. fireball.

You sir are a horrible, horrible person :smallbiggrin:

I like it.

[Yora]

Do you just need to destroy everything within the stone walls, or do you have to get rid of the stone walls themselves?

[Mauve Shirt]

Just the stone walls themselves, at this point. Killing everything inside wouldn't be THAT bad. The thing inside that we want is practically indestructible.

My chaotic evil wizard REALLY LIKES the flesh to stone idea!!! However, my chaotic good self is kind of grossed out. :smalltongue:

[Fouredged Sword]

How big are some of the pieces used to make the castle?

Animate Objects to make them jump up and kill the people inside themselves.

[Chronos]

Does it specifically need to burn, or is any form of similarly-thorough destruction acceptable? Because if the latter, sonic attacks tend to work well (though I'm not sure if exactly the same ones are available in Pathfinder).

[angry_bear]

There was an old AD&D 2nd Edition Druid spell that was designed specifically to destroy stone structures called Ivy Siege. Basically how it worked was in the span of 3 turns, a stone structure such as a tower (A Castle required multiple castings) would become covered in ivy, then made a save for 3 turns afterward, and with each failure it would take some siege damage.

I'm not sure if it was converted into 3.X, but if it wasn't, a more experienced player than myself could probably update the spell for you...

[avr]

Wall of fire tends to be better at setting fire to things like wooden floors, ceilings, supports and furnishings (included in most stone fortresses) than fireball.

If you want to wreck the fortress fast transmute rock to mud on the foundations will generally do the job.

[Raven777]

What is your class and level? What resources are available to you? If you have high level necromancy backing you up, incorporeal creatures like Shadows and Wraiths could get in and ghostmurder everybody. If you prefer Conjuration, I'm sure a few Xills would be glad to help you out in exchange for a castle full of meatbags to lay their youngs.

These things all have abilities that let them look at walls, shrug, and go right through.

[erikun]

I am pretty sure there is a valid official Transmute Stone to Lava spell in one of the 3.5e books, if they are allowed. There is also Summon Nature’s Ally III (and higher) allowing you to summon Thoqqua (http://www.d20srd.org/srd/monsters/thoqqua.htm) to dig through walls and basically melt the whole thing to slag. Again though, not sure if that's still in Pathfinder.

[tiercel]

Well there's this thread: How do you destroy a City? (http://www.giantitp.com/forums/showthread.php?t=239214)

It's for a whole city, and it starts off as a "Locate City Bomb" thread but becomes more general in nature mostly on page 2, but it should yield some ideas.

Partly your answer will depend on what exactly your primary objective is—to destroy the outer walls, collapse/destroy the entire structure, whether you primarily want to *burn* as opposed to other types of destruction, or if at the end of the day you just REALLY need the McGuffin inside the fort and would like to wreak havoc in order to get it.