Military tactics vs. high-level spellcasters

[RangerWickett]

Say you've got an army of 10,000 men, most of them 4th level or less. And you want to sack a fortress that has 20 mid- to high-level spellcasters and say 500 soldiers. The fortress is on a peninsula, has high ground, and is the size of a small castle, with a surrounding town. It will take the army a month to arrive.

What kind of tactics would you use if you were the general of the army? The general is a high level warrior-type class, with mid- to high-level bodyguards, and the necessary protection to avoid a scrysassination attempt.

What kind of defenses and tactics would you use if you were the leader of the mage fortress? Assume you have access to a lot of 3rd level spells, a fair number of 4th, and progressively less of the higher level spells, of different classes.

For the record, I'm asking specifically for D&D rules ideas here. Try to minimize use of things that aren't already in the rules. I'm concerned both with prep and with the actual battle.

 

[S'mon]

In this siege/assault scenario, if you don't have air superiority you're dead meat. Per the RAW the spellcasters fly over the enemy lines, if they're Wiz-10 they can fireball from 800' away AIR; if they have prot fr missiles, mirror image, stoneskin et al they could probably even do close-in runs too. They can drop their load, return to castle, 8 hours rest & back if necessary - unlikely, a few Wiz-10s can kill thousands of troops in 1 day.
My advice to the army commander: Unless you can recruit a ton of dragons, don't bother. Your only chance to even survive these guys is build a big dungeon fortress & let them attack you!

 

[S'mon]

My overall advice to both sides: Wipe out enemy fliers, gain air superiority. At that point you've effectively won. I've been running D&D battles for over 20 years, and this is always the case unless there are hundreds of thousand of cavalry on the battlefield, in which case area-effect spells may not kill enough of them.

 

[Piratecat]

If I was the general, I'd train the archers - who have had magic weapon cast on their arrows, right? - to all practice firing at ONE target. One arrow in 20 is going to hit a high level adventurer, but if 500 archers with rapid shot all aim simultaneously at one wizard, 50 arrows are going to strike him. Then they move on to the next adventurer.

 

[takasi]

Use an artifact that summons a pillar of flame to teleport the army directly into the fortress.

 

[takasi]

If I was the general, I'd train the archers - who have had magic weapon cast on their arrows, right? - to all practice firing at ONE target. One arrow in 20 is going to hit a high level adventurer, but if 500 archers with rapid shot all aim simultaneously at one wizard, 50 arrows are going to strike him. Then they move on to the next adventurer.

I don't think this will work. High level wizards can easily have enough potions or scrolls of greater invisibility for their flying bombardments.

 

[Mallus]

Surrender?

 

[Drowbane]

Say you've got an army of 10,000 men, most of them 4th level or less. And you want to sack a fortress that has 20 mid- to high-level spellcasters and say 500 soldiers. The fortress is on a peninsula, has high ground, and is the size of a small castle, with a surrounding town. It will take the army a month to arrive.

What kind of tactics would you use if you were the general of the army? The general is a high level warrior-type class, with mid- to high-level bodyguards, and the necessary protection to avoid a scrysassination attempt..

Hire 4-6 "Heroes" to assassinate the Casters?

What kind of defenses and tactics would you use if you were the leader of the mage fortress? Assume you have access to a lot of 3rd level spells, a fair number of 4th, and progressively less of the higher level spells, of different classes.

For the record, I'm asking specifically for D&D rules ideas here. Try to minimize use of things that aren't already in the rules. I'm concerned both with prep and with the actual battle.

Scry and Fry.

 

[Shane_Leahy]

Everyone is saying that AOE will kill the attackers so how do you deal with it?

Disperse your troops, don't have any large concentrations of them. Since the army inside the castle is so small, you should not have to worry about your army being taken apart piecemeal.

Best way not to get AOE'd is to get your troops in with the enemy as quick as possible. No Siege, lots of ladders, and get on those walls fast. Sure, you will lose alot of men but you will lose them no matter what. Also you stated that there is a town around the castle. If you can get to the town before too many citizens are safely in the castle you should have some protection from the wizards. Not a nice way to do it.

Deception. Can you make the wizards cast alot of spells on the wrong targets? Then when they are resting hit them?

Sneak attack? Use those bodyguards and any rogue types you have to sneak inside the castle and open the doors for a quick charge.


Could the General 'invite' a scryassassination and ambush the arriving mages? Eliminate some of them that way?

 

[Kae'Yoss]

Spell assassination will be a problem. You say it will take them a month to get there. It's quite possible that the spellcasters will find out - if they don't know already.

That means that every once in a while, a spellcaster will teleport there, a bit away from your army, will launch some destruction, and be gone again.

They will buff (including invisibility probably), teleport there, do a couple rounds of action, and be gone again.

Stuff like Teleport, time stop, some cloud kills and delayed blast fireballs, and teleport away. So all of a sudden, poison gas and fire is felling your warriors by the score. Or just teleport some way away, with ample cover, and fire some meteor swarms, or launch a storm of vengeance. Or summon critters and let them loose on the army.

Unless you find ways to counter these sorties, morale will suffer.

Oh, and suspect that any obstacle will be worse: Rivers will have no bridges any more (if they do, be wary, for they might crumble under your feet) and boats might have trouble ferry across because of all the imported sea monsters. Treacherous paths will be more so with cunning appliance of magic.

As for the siege/assault: This will be tough. Make sure everyone has a ranged weapon, or this could get really ugly: They pick off the archers and then fly over your army with impunity, faining death from above (they might do so, anyway, getting protection about mundane weapons).

The wizards will be on the battlements, anyway, probably in prismatic spheres, launching spell after spell.


By the way: What kind of men are in your army? Only warriors? Some adepts? Fighters and wizards? In what numbers (approximately)