Making an area as inhospitable as possible.

[Amechra]

So, what spells do you know of that make a large area as inhospitable as possible?

I can think of the following off the top of my head:

Shadow Landscape (Druid 9th): Generally fucks up your enemies by making the terrain more hostile.
Fimbulwinter (Druid 8, Sorcerer 8, Wizard 8, Cleric 9, Winter 9): plunges a massive radius into winter for at least 4 weeks (if you know what you are doing, you can get it up to 2*(48+2d12) weeks, which is between just under 2 years to up to just under 3 years)
Skyrift (Sorcerer 9, Wizard 9): Permanently turns a mile-radius area into night.

So, any others? I'm kinda working on an Epic Spell using the Feanmerc Epic Spellcasting fix, and I want to make a large area as unlivable as feasibly possible.

[Gazzien]

Global Warming, from Sandstorm: Raises an area's temperature band. Not compatible with Fimbulwinter Ice Age, IIRC, and it's also a RAW Epic spell.
Ice Age, from Frostburn. Opposite. Still RAW Epic.

But that's all I've got, off the top of my head.

[linklord231]

Well there's Storm of Vengeance or Apocalypse from the Sky if you just want to kill lots of things in a wide area.  SoV is max 10 rounds and AftS is instantaneous, so they're both rather short duration though.  Evil Weather from BoVD can do some nasty things, including cutting off divine spell access.  Again, duration is only 3d6 minutes without shenanigans. 

[wotmaniac]

Control Weather?

[zook1shoe]

Reality maelstrom

[Amechra]

Alright, so by current calculations, the epic spell affects a radius of 20 miles with permanent night and blizzard conditions, with the terrain being difficult to navigate, and it is filled with horrifying winds that make flight a really bad idea.

I'm not going to use Reality Maelstrom, since it doesn't mesh too well with the Dimensional Anchor I'm thinking of throwing on.

The plan is to make a horrible area that can't be bypassed, after all...

What was that spell that worsens difficult terrain, again?

[Gazzien]

Alright, so by current calculations, the epic spell affects a radius of 20 miles with permanent night and blizzard conditions, with the terrain being difficult to navigate, and it is filled with horrifying winds that make flight a really bad idea.

I'm not going to use Reality Maelstrom, since it doesn't mesh too well with the Dimensional Anchor I'm thinking of throwing on.

The plan is to make a horrible area that can't be bypassed, after all...

What was that spell that worsens difficult terrain, again?

I can't find one to make difficult terrain impassable, but you might want to look at Ice Rift? (Earthquake, but for snowy environments.)

Possibly Wrack Earth, as well (though that'd be more for the characters living within this area).

[Amechra]

I just found Halaster's Teleport Cage from CoS:W; it is loveliness incarnate.

To sum it up, it creates an area that you can't teleport into or out of; if you try to teleport inside, you end up in a random area inside the "cage." Teleport spells that try to get you in teleport you to some random place that is within the range of your teleport effect.

It's going into the mix.

[Nytemare3701]

I just found Halaster's Teleport Cage from CoS:W; it is loveliness incarnate.

To sum it up, it creates an area that you can't teleport into or out of; if you try to teleport inside, you end up in a random area inside the "cage." Teleport spells that try to get you in teleport you to some random place that is within the range of your teleport effect.

It's going into the mix.

CoS:W also has Binding Chain of Fate, which is a really small area, but I'm sure this forum can figure out a way to give it a larger one.

[Empirate]

Nightmare Terrain comes to mind, for the lower levels. Small area, though.
Guards and Wards is in Core, for indoor terrain.
Darsson's Chilling Chamber and Darsson's Fiery Furnace probably qualify as well, fun stuff.

I have to second Control Weather, btw. Awesome spell.

Also, don't forget to throw in some mundane environmental effects, like acid fumes (should be pretty frequent in e.g. volcanic areas), which force saves to avoid Con damage. Ouch.
Then there's Black Sand (Sandstorm) and similar supernatural environmental hazards.

[Amechra]

The nice thing about the Feanmerc system is that I can use the best area out of all the spells that I chose as its radius.

Fimbulwinter has a radius that measures in miles.

So the area of the spell doesn't exactly matter.

However, it uses the shortest duration, which is hours/level for the spells I've got, and it takes x5 to make them Permanent...

At this point, I just need something that will stop them from burrowing, and something that will stop them from going Incorporeal/Ethereal, and I'm set.

Seeing that, since this pools effects, and Shadow Landscape explicitly makes the caster immune to the spell's effects...

The entire epic spell pools the effect.

I might want to start cutting down on the DC, though; it's getting near 300 with mitigation (Feanmerc only lets you mitigate up to half the DC, so...)

Now I just need to pump spellcraft to an absurd degree!

*This isn't for an actual game; this is just me seeing what kind of deathlands I can create.*

You know, maybe a nice Snowsong would be neat to throw on the effect; it would make the blizzard even more lethal, for one thing, and would give Charisma penalties and spell failure chance... Along with giving my friends a nice FH 1 and enough cold resistance to survive the perpetual blizzard.

[sirpercival]

Black Labyrinth

[Amechra]

Black Labyrinth

I forgot about that delightful "spell"; I don't think that it can RAW be slapped into the epic spell I'm making, but screw that noise, it's going in.

Alright, now I've got calculations going on... bear with me. (I'm going by the "cannot mitigate the thing below half", so I'm only going up to DC 150 final.)

Fimbulwinter (+28 DC)
Darsson's Chilling Chamber (+16 DC)
Shadow Labyrinth (+30 DC)
Shadow Landscape (+30 DC)
Halaster's Teleport Cage (+30 DC)
Nightmare Terrain (+18 DC)
Skyrift (+30 DC)

DC 182 before further modifications.

Double Radius (+4 DC)
Reduce Casting Time to 1 minute (+18 DC)
Reduce Casting Time to 1 round (+18 DC)
Reduce Casting Time to swift action (+30)
Increase duration to 24 Hours/CL (+46)

DC 398 before mitigation.

(As funny as it would be, I'm not going to take the -10 "reduce the area of this spell to single target" option)
Reduce the range to 1/32nd of the original (-20 DC)
Needs 8 other spellcasters donating 8th level spells (-120 DC)
Take 5d6 backlash damage (-10 DC)

For a final DC of 148 (1 below my target minimum); this is effectively a 22nd level spell, by the way.

Let's say I cast this at CL 40 (enough to protect my buddies that helped me cast the spell from the effects of the spell), it would last for 40 days, would cover an 80 mile radius where travel by everyone but my buddies and I is severely restricted, and I can still cast it up to a quarter of a mile away from our lair/hangout.

Oh, and due to a bit of weirdness about Nightmare Terrain, anyone who so much looks at the unnatural darkness of our hell winter is entangled.

This is nice and lovely (I left Control Weather out... that'll go in the spell that is layered on top of this one. Actually...)

Cast at the same CL 40...

Well, it has a DC 1 point higher than the above spell (which needs a nice, pretentious name), but it will do... It also is a 22nd level spell.

I call it "The Perfect Storm". It permanently alters the weather within 36 miles to whatever I find appropriate, I can change it as a standard action, and I can end the effect on a whim.

The cost? I merely have to take 40d6 backlash damage (which, mind you, is unblockable damage), and spend 7000 XP.

And the beauty of the Feanmerc system is that it works off of Improved Spell Capacity, so I can prep either one in a 22nd level slot.

The only issue is that most of these spells are on different spell lists, so I'll have to go Archivist... Oh well?

I think these are perfectly nice spells.

(By the way, a permanent Prestidigitation effect that affects about a two person-sized areas (using a generous estimate of 3 cubic feet (we are somewhere between 1.5 and 5 cubic feet.)) is a 13th level effect, roughly? I think the way they estimate levels is kinda silly, but that is besides the point.)

[Garryl]

Spells can't affect anything beyond their range, so dropping the range to 1/32 kinda defeats the purpose. Better find another way to mitigate 20 points of the DC.

If any portion of the spell’s area would extend beyond this range, that area is wasted.

(It's the same thing that makes many uses of Widen Spell pointless.)

[Amechra]

Damn, that means that I'll have to pump the range as well...

I can just take a bit of XP cost and Backlash instead, so it ain't a biggy.

[linklord231]

Why are you reducing casting time to a swift action if you're not planning on doing it in combat?

[Amechra]

...Good question.

I think I was going with "I cast this and then I bust out my actual offensive weaponry when everyone else is in deep fuckwater."

But it might be better idea to drop that and just grab a shit-ton of range and area boosters. So I can hit everyone within a decent-sized country with a casting or three.

[linklord231]

I kinda figured the intent was to have the spell running all the time (rather easy to do with a duration of over a month).  If you're hanging out in the middle of it, then there shouldn't ever be a need to cast it quicker than 1 round.  Heck, you could probably get away with a casting time of 10 minutes or longer and still not really have to worry about it.

[Halinn]

Can you use the locate city bomb for getting that huge radius?