Can sieges withstand magical assault?

[Ryltar]

Well, hard to answer, that one. Magic would be tipping the scales in either side's favor: the one that has got more (and powerful) casters can make up many other deficits, i.e. less regular troops, terrain disadvantages, no cover ...

If both sides were equally matched, I think it wouldn't change a thing in comparison to a regular siege.

 

[kigmatzomat]

I think people are ignoring the intelligence of the fortress builders. Magic resistant architecture would be common. I don't mean enchanted walls but walls designed to resist magic attacks. You'd use layered walls separated by air, sand, soil, water, etc.

Disintigration is defeated by having sand between stone or earth walls. Sure, you destroyed 10x10x10 but the sand from the rest of the wall flows into the hole. Elemental spells are less effective against walls with air gaps because each successive wall gets to apply hardness again. Stone Shape fails against earth, Dig is useless on brick. Burrowing creatures drown when they breach cisterns in the walls.

Walls would be spaced out more and located farther from the main keep. Many walls would be of adobe or brick, materials not incredibly useful to the invaders that would have to be broken down to allow ready passage. The defender would have permanent siege engines with massive range (trebuchet anyone?) in excess of what most invaders could manage.

Mix in some trained animals and mystical creatures. Falcons hunt fliers in the day, bats at night. Some creatures may be dire (dire eagles, dire bats), others magical (groups of shocker lizards), and a few could be sentient (xorn or fey). These would be permanent fixtures at the fortress and no few of them would be secrets, possibly held only by the Lord's family.

These kinds of structures would be able to ablate a large amount of mystical assault, with or without onsite casters. If you remember LotR there were series of walls and defenses; that theory is sound and will be amplified but not obsoleted.

 

[Dracomeander]

Siege Specialists

There is one thing no one has considered yet. If sieges are going to be part of the standard of warfare in a magical world, there would develope a whole field of specialists concentrating on finding new magics and applications for siegecraft. Welcome to the fantasy arms race.

In a more conventional fantasy world, there is one power available to psions that I could see a wizard researching to have available - Energy Wall (Sonic). That power or spell alone throws a wrench in any siege calculations. Put the Energy Wall next to the castle wall and wait for the castle wall to vibrate apart.

 

[Hitokiri]

You know, this is interesting enough I may see if my group is willing to suspend normal adventuring this weekend to run a few simulations. Have to design a cast beforehand, and work out whatever modifications are needed, but have the players controll the attackers with PC's being spellcasters and see if they can get through various defenses and successfully storm a castle.

 

[azmodean]

Here's some numbers to go with the "magic can make walls tougher" statement:

Magically Treated Walls: These walls are stronger than average, with a greater hardness, more hit points, and a higher break DC. Magic can usually double the hardness and hit points and can add up to 20 to the break DC. A magically treated wall also gains a saving throw against spells that could affect it, with the save bonus equaling 2 + one-half the caster level of the magic reinforcing the wall. Creating a magic wall requires the Craft Wondrous Item feat and the expenditure of 1,500 gp for each 10 foot-by-10-foot wall section.

So stone for instance, (hardness 8, 15 HP/inch of thickness) becomes magically treated stone (hardness 16, 30 HP/inch of thickness, with a save of about +7 to +12) This thing laughs at most energy-based spells, and I'd give it at least the magical half of the hardness vs even acid or sonic attacks.

A scroll of disintegrate has a save DC of 19, but I figure a NPC or PC that can cast it will require a save of at least 22, which gives them a success rate of 45% even if the wall was enchanted by a lvl 20 caster. Also this process is expensive enough that it probably couldn't be done on a city wall, perhaps just on a keep or on a gatehouse/gate. So the primary defense against disintegrate is still multiple walls or detecting and preemtively attacking the caster.

 

[Narfellus]

In all honesty, a high magic campaign with powerful spellcasters on both sides would so skew the reality of "siege" combat as we're historically used to it, there's really no comparison. But i'd sure as hell like to run the simulation sometime. Sounds like a blast, using every magical trick you can think of to breach the walls, and every trick to defend them. You could have your players split up on two teams and plan accordingly, and let 'em have at it.

 

[Ibram]

There are a few things to consider when thinking about magic in seiges:

1) what kind of magical modifications can be made to a castle? Things like giving the walls spell reesistance or creating large permenent circles o' protection can give the defenders a good advantage.

2) what kind of spell caster are we talking about here? A cleric would be far more valuable durring a seige then a wizard/sorceror could be (casting healing spells, cure disease, and bless type spells).

3) how many casters are we talking about and what level are they? I'd wager that a wiz/sorc under 5th level would have very little impact on a seige (where as even a low level cle/dru would be able to tip the scales.

Remember that attacking a prepared position is one of the worst possible situations a general can find himself in. To break such a position you have to have a significant advantage in either manpowe or firepower. Magic doesnt change that, it just adds a pretty light show to the battle. As long as both sides have equal access to magic the defender will win.

 

[Nail]

Most of you have missed the point: Creating a magically protected castle takes lots and lots of gp. Destroying said castle does not. Simple.

Sieges, as we think of the term, simply cannot exist in a magical setting. They just don't happen.

 

[Darkness]

I'm with diaglo.

If the forces and tactics are equally good, the defenders will win, barring massive random chance.

Better to "ninja the place," as Storminator so aptly put it.

 

[Hand of Evil]

Are there guilds in the world?


Rule 7, page 12, subparagraph 4, small print statment:

...wizards that use their power in the defense or the breakage of a siege loose all properity and standing within the community, brotherhood and sisterhood of the following orders(1). They also are labeled outlaw with a bounty of no less than 5000 gp on their head and the reward of all spell related objects as part of said bounty...

1) The following orders have agreed to and have recognized these bylaws:
...The Green Brotherhood
...The Order of the Magi
...The Scarlet brotherhood
...The Hag Sisters
...The Witches of Eastwiche
...