looking for ideas on how a spellcaster can bring down a city

That's why it's double bonus points (for your group being dense).

A half-dozen Epidemic spells?

A few mass fly spells will get your horde in the city.
Wall of Stone can make a ramp.
Teleport Circle can also breach their defenses.

Meteor Swarm doesn't do much to high level characters, but it'll crush a lot of mooks.

Epidemic, Plague Storm or Cursed Earth bring bioweapons into your mix. Use all three for best effect.

Put symbol of X on objects and teleport or toss them into populated areas.

This is just too easy...

Control Winds @ Level 20. Instant escalation to Tornado force winds. Should tear apart nearly every structure and most of the people stuck inside too.

Anyone left standing after that by default must have more than a few HP and you then wallop them with your A-game spells.

Since he has access to scrolls and things too - he could easily put a Level 20 Control Winds bomb into a Greater Glyph of Warding (set on something simple like opening a scroll tube) and then have some charmed schmuck wander into the center of town and trigger it.

Maybe once the damage is done, send in another schmuck and do it again to whatever is left.

Rain down pamphlets on the city that contains a treasure map to a hidden treasure within the city. Oh, and the pamphlets all contain explosive runes, too. Boom, baby.

This would result in the town still being more or less in tact... You then have the option of either leaving a ghost town...

Literally.

Literally make it a ghost town. You're a 20th level Lich, this has to be doable.

O.J. Pinckert wrote:

This would result in the town still being more or less in tact... You then have the option of either leaving a ghost town...

Literally.

Literally make it a ghost town. You're a 20th level Lich, this has to be doable.

The Shadowpocolypse only requires a 3rd level caster, one 2nd level spell, and you retain indirect control of all shadows while leaving most of the city intact.

People keep insisting on hugely overpowered 9th level spells and major planer entities or arming and equipping armies. The smart wizard expends the minimum required resources.

Well yeah, the smart wizard. What we have here is a sorcerer. Cmon man.

If there's a forest nearby he could also use sige of trees or its greater form to get some instant catapults for his army.

1000 sims of creatures with a decent STR and some int, griffins work. Grab 1000 commoners. Fly over the city with you hostages. Drop 50 every round they do not surrender. If they fight, just leave and repeat somewhere else. Oh yeah drop them all at once if they fight.

Well yeah, the smart wizard. What we have here is a sorcerer. Cmon man.

Ahhh, if we are talking sorcerer, Paizo needs to bring back the spell Unleash Monolith.

You're assuming you need to bring the walls down quickly but that's not needed.

The lich should use disintegrate to hollow out a sufficient section of wall, leaving only a thin layer intact so nobody realizes what's up--he isn't operating under a time limit here, the number of castings needed doesn't really matter. Now he can quickly take down that last bit and let his army in.

For style points, excavate a vast pillared chamber under the city in the shape of a long inverted hollow cone, and then without warning knock out the supports and drop the whole place into a smoking crater that smashes what used to be the ground in on itself as it falls. It's both clean and unspeakably messy.

OK clearly I need to give more details but I really like the summon some pit fiends with gate and the astradaemon idea. Also the control winds spell would work wonders a tornado would destroy everything except for the walls.

Someone else has his phylactery and the lich is simply a pawn of someone much more powerful. Actually a high ranking general of Orcus.

The lich is also under some sort of time limit. The PCs were given means to leave and stop this general from acquiring a dangerous weapon for Orcus. So the lich has to kill them before they leave.

His resources are not insanely unlimited also he (and me as a dm) doesn't want to risk giving all of his scrolls and stuff to the PCs if he is destroyed. He has a contingency spell in place to teleport him away if this happens even if he is destroyed his body will be teleported away.

thanks for the ideas

Mr. Bones the Dragon
Find a dragon, raise it form the dead. There you have done it.

Undead Corruption
Or just slowly assassinate leaders in command, raise them from dead then use ghost sound or ventriloquism to make them sound like the person. You can now slowly destroy the city from the inside out with disguised undead.

Lover's Quarrel
Another speedy idea, and this one gets a bit awkward, cast unnatural lust on a lot of the more powerful people get them to easily follow your command. Then cast lover's vengeance to make them more powerful due to unnatural lust this should work. If they don't follow you then cast command on them.

Disease Pillar
And last but not least, this one is my favorite. Create a undead from something with a decent amount of hit points. Cast multiple uses of Greater Contagion on it. Have it walk into the city and start touching people and what not. Basically spread the diseases.

Names Artifix, I love coming up with weird ideas to destroy things >:D

The best city destroyers aren't even lich sorcerers, really, they're druids. If your lich has access to druid scrolls and can properly use them, then throw a few tricks from the Druid Death To Civilization Toolbox at them:

World Wave levels every building within the walls. Then Control Weather and Control Winds stack, so they give you a 1.6 kilometer wide legitimate tornado, carrying the debris from the World Wave. So that alone would do it, with purely environmental effects. Much more effective than Storm of Vengeance even.

If you want to be more mundane about it, Greater Siege of Trees gives you six gargantuan trebuchets hurling an infinite supply of rocks for 20 continuous hours at the same point in the wall, or up over the wall. They'd have to at least come out and confront you.

If you're raiding the door, Blood mist the guards at the gate means they lose control of the front door for 20 minutes. If it's metal, transmute metal to wood gets it a form you can use, then woodshape around the hinge points and the door falls down. So that's a quick and dirty way in.

If your antagonist was actually a druid, you could do all this wildshaped as a bird sitting in a tree in the town square, spontaneously summoning purple worms and whatnot.

World Wave levels every building within the walls. Then Control Weather and Control Winds stack, so they give you a 1.6 kilometer wide legitimate tornado, carrying the debris from the World Wave. So that alone would do it, with purely environmental effects. Much more effective than Storm of Vengeance even.

That's not how World Wave works...

If the wave encounters terrain that it cannot incorporate into itself, the wave simply flows over or around the obstacle unless the terrain occupies one-half or more of the area of the wave's crest. In such cases the spell ends in 1d6 rounds as the wave falters and collapses, unless its duration would normally cause it to expire prior to that. [..] Terrain the wave cannot incorporate includes anything primarily made from fire (such as lava), air (such as an open cliff face), or something man-made (such as a city).

Assuming a 20th level caster half the area of the waves crest (30ft high, 205 ft wide) is 3075 sq. ft, a small towns city wall (let alone the town behind it) occupies far more space than that. So when the Wave hits a city wall that wall takes 6d6 damage per round for 1d6 rounds. That's it, on average 10hp a round past the walls hardness, doesn't even hurt it too much, certainly it doesn't level it and the city behind it. Even if the GM decided the wave could crest the city wall, it still exceeds the area it can incorporate and so collapses, maybe doing some damage to a few buildings, but far and away from destroying the town.

You're a druid. You cast it from inside the walls, leaving the wall but turning all the buildings in the town to mincemeat.

However, anything else coming into contact with the wave takes either 6d6 points of bludgeoning damage (if the tsunami) or 1d6 points of bludgeoning damage (if the swell).

The wave damages any manufactured object or structure.

Then you tornado the debris, turning the occupants to mincemeat. First by Control Weather (probably do this before World Wave due to casting times)

You change the weather in the local area. It takes 10 minutes to cast the spell and an additional 10 minutes for the effects to manifest. You can call forth weather appropriate to the climate and season of the area you are in. You can also use this spell to cause the weather in the area to become calm and normal for the season.

You control the general tendencies of the weather, such as the direction and intensity of the wind. You cannot control specific applications of the weather--where lightning strikes, for example, or the exact path of a tornado. The weather continues as you left it for the duration, or until you use a standard action to designate a new kind of weather (which fully manifests itself 10 minutes later). Contradictory conditions are not possible simultaneously.

Control weather can do away with atmospheric phenomena (naturally occurring or otherwise) as well as create them.

A druid casting this spell doubles the duration and affects a circle with a 3-mile radius.

6 miles across gets the whole town easily. Then you control winds, giving you a 1,600 ft diameter tornado centered on you, as you fly around town in air elemental or bird form, with a tiny eye in the middle so you're fine. Arguably, you may not need the Control Weather at all, depending on how high a caster level you're throwing Control Winds at.

Tornado (CR 10): All flames are extinguished. All ranged attacks are impossible (even with siege weapons), as are sound-based Perception checks. Instead of being blown away (see Table: Wind Effects), characters in close proximity to a tornado who fail their Fortitude saves are sucked toward the tornado. Those who come in contact with the actual funnel cloud are picked up and whirled around for 1d10 rounds, taking 6d6 points of damage per round, before being violently expelled (falling damage might apply).

...and that doesn't even include damage from the debris caught in the tornado.

Hell, based on text within Control Winds, you might not even need the World Wave:

A tornado (175+ mph) destroys all nonfortified buildings and often uproots large trees.

Presuming every building in the town isn't a fortification, they're all immediately destroyed and turned into flying rubble, while everyone in town takes somewhere between 6d6 and 60d6 points of damage, from that one 5th level spell alone.

For style points, excavate a vast pillared chamber under the city in the shape of a long inverted hollow cone, and then without warning knock out the supports and drop the whole place into a smoking crater that smashes what used to be the ground in on itself as it falls. It's both clean and unspeakably messy.

If going this route, just hire a duergar engineering team.

You're a druid. You cast it from inside the walls, leaving the wall but turning all the buildings in the town to mincemeat.

Fair point, but the spell still ends in 1d6 rounds though.

Terrain the wave cannot incorporate includes [...] something man-made (such as a city).

Overall 6d6 Blugeoning damage to a building isn't going to do that much since the wave passes them by in a single round, after hardness you're looking at 13-15 pts of damage on a building, that's... not much.

It's definitely a useful approach for a Druid, but since the caster in question is Arcane it's a bit of a tangent, that said, Wish can always potentially replicate the effects. It is however less likely to actually achieve his ultimate objective I think, which is to kill the party, the towns destruction simply being a way to get them spread out and vulnerable. If they have distinct threats to counter they're more likely to split up to do so, if the entire town is being World Waved/Tornado-ed they really don't have much incentive to do anything other than stand around their casters as they try to dispel magic.

OK clearly I need to give more details but I really like the summon some pit fiends with gate and the astradaemon idea. Also the control winds spell would work wonders a tornado would destroy everything except for the walls.

Someone else has his phylactery and the lich is simply a pawn of someone much more powerful. Actually a high ranking general of Orcus.

The lich is also under some sort of time limit. The PCs were given means to leave and stop this general from acquiring a dangerous weapon for Orcus. So the lich has to kill them before they leave.

His resources are not insanely unlimited also he (and me as a dm) doesn't want to risk giving all of his scrolls and stuff to the PCs if he is destroyed. He has a contingency spell in place to teleport him away if this happens even if he is destroyed his body will be teleported away.

thanks for the ideas

Ah, so the lich's real enemy is not the party at all but rather this General of Orcus. The party might be the lich's best chance of winning his freedom. I think what the lich should do is surreptitiously approach the party and give them information that they can use to go after this Undead Demon General of Orcus.

He can use the village as a bargaining chip, threatening to destroy the village of poor innocent people if they don't cooperate, use the village as a diversion, keep the Orcus-General's eyes on the burning Village while the party sneaks into the castle and lays on. The Lich will pop in at just the right moment, steal back his soul object, and teleport away.

Ah, so the lich's real enemy is not the party at all but rather this General of Orcus. The party might be the lich's best chance of winning his freedom. I think what the lich should do is surreptitiously approach the party and give them information that they can use to go after this Undead Demon General of Orcus.

He can use the village as a bargaining chip, threatening to destroy the village of poor innocent people if they don't cooperate, use the village as a diversion, keep the Orcus-General's eyes on the burning Village while the party sneaks into the castle and lays on. The Lich will pop in at just the right moment, steal back his soul object, and teleport away.

Yes the lich is not a fan of this guy but he still does what he is told, someone who is undead does not want to get on orcus's bad side. when the party confronts the owner of his phylactery (the owner has a refuge spell bottle to break bringing the lich to him) and if the owner dies first the lich takes a move action to get to him, move action pick up phylactery (we can even make that a standard for searching around.) and then quicken dimension door to get out never to be seen by the PCs ever again.

...

It's definitely a useful approach for a Druid, but since the caster in question is Arcane it's a bit of a tangent
...

The spellcaster is a level 20 sorcerer lich very knowledgeable in the use of scrolls (+40 UMD) and he has more powerful friends that can provide him with any scroll he wants.

The lich can acquire druid scrolls and use them (up to CL 20) without fail (casting a scroll is DC 20 + CL) and has an 18 wisdom so more than enough to use control winds scroll at CL 18. A tornado ripping through town is more than enough to destroy a very large portion of the city. who needs to bring down the walls? just destroy everything but the walls.

Found a spell Jatembe’s Ire (Wiz 6) in Arcane Anthology. It comes out of the spellbook Wisdom of Jatembe. Basically it makes a bunch of vines and such kill evil creatures and destroy buildings. Just don't be in the area if you're an evil lich.

Yes the lich is not a fan of this guy but he still does what he is told, someone who is undead does not want to get on orcus's bad side.

So is Orcus actually a part of this design? I can see it being a problem if you interfere with Orcus's actual plans, but why would killing a general of Orcus put you on his bad side?

The thing about Orcus is that he's Evil. He doesn't have any loyalty for the people under him. If you kill his general, he might not see it like he's lost a valued employee and family friend. When you kill Orcus's general, he might even see it like you are doing him a favor by ridding his army of someone who is so incompetent that he could be killed by you. That's evil for you, especially Chaotic Evil. I don't know about your campaign, of course, but in all the descriptions of Orcus I've ever seen, Orcus is Chaotic Evil. The lich might even step up after the general is killed and take credit for manipulating the party into doing the general in, proving that he should take the general's place!

Meanwhile, what bad side? Does Orcus have a good side? Who cares if you are on his bad side? Again, a lich's best strategy is usually to escape all notice, steal back his soul receptacle, and teleport far away to somewhere where he will never be found and be free to conduct research into how to extend his life even longer, hopefully to never die and never have his soul enter the Abyss where Orcus awaits him. Anyway, by all accounts I've seen, Orcus HAAAATES the Undead that worship him, and Liches are probably smart enough to know they're already on Orcus's bad side just because. It seems that the whole point of being a lich is flee final judgement in the first place.

Even if this is Orcus's personal project, and the lich is under a great deal of pressure to do what he's ordered to do, it still might be worth his while to fail on purpose and in so doing slip the party important information for killing the general for him, deflecting blame from himself and recovering his wicked soul through treachery.

Having read the advice control weather's top end option is pretty much the best within pathfinder rules destruction option. If you want to go old shchool 3.5 had many crazy spells that'd give you a guideline for a high damage event, I would link 3.5 Tsunami but can't find it anywhere seems new edition versions from D&D 4th & 5th ed over wrote it but here's a druid version which is actually quite nasty could give it an evil vines of the dead feel?

http://www.dandwiki.com/wiki/Verdigris_tsunami,_perfect

Personally pazio keep crazy spells out of our hands for a reason of sanity, I can't be bothered to find my 3.5 box or i'd link a few others, some were whole heartly mad like Tsunami. It was basically insanity you'd kill so many people, I think it was messured in miles it was never useful to anyone not chaotic evil as you'd be becoming chaotic evil using it.

What you need is frankly a GM event sort of thing your gonig to have to wing it and make up a spell, I think also give the liche epic levels as you'll need it verus a lvl 19 party. Go some sort of Tsunami if your by the sea or just rain down fire and brimestone like a good old end times, he might make some infernal deal to summon in a devil army into the city or something, that should get the heroes out and facing him.

Remeber they use the rules you make the rules have fun.

Yep. Control Winds at CL20 gives you your tornado without any other spell. The Control Weather / Control Winds combo is only necessary if you're a lower level caster and trying to achieve the same trick.

Level 20 lich huh.

Is this the point where I just refer to Order of the Stick and tell to use that as inspiration? xD

These are some good ones. I really enjoyed reading through the insanely evil ideas. I am bumping this to the top to get more from the community so I can get my evil thoughts fix!

Undead Betrayal
Does the party have anyone close to them? Just assassinate the people closest to the party, reanimate them, then use them as the strings to turn your puppet party into mass murders destroying the city.

A Party Against Itself
If any of the party members are evil or neutral, then offer them eternal life if they kill their party members. Then let them do the deed and reward them with eternal undeath.

Insanity Mines
Use Greater Invisibility to turn invisible. Then wander around town laying Symbols of Insanity in the streets. When npcs or the party walks by they pass over the symbol, this activates the symbol and your npcs or party starts killing everyone! If you want to make them not detect your the one doing it, make the runes at night and cast permanency on them!

"Me start reading the thread: some cool and interesting ways to level the city".

Then I read Gargs454 post:

"Personally, if I were the lich, I'd just toss a Deck of Many Things into the city. Problem Solved."

"Me: "BWAHAHAHAHAHA!" I probably woke up the neighbours..

It's the same as putting the party in a room full of nothing but a big red button on the wall with a deathskull sign above it and the text below "Do not push". ^^

Anyways my advice is: Let the party be the ones to have the lich's army enter, by accident or choice.

Have fun! =)