Defending a castle from the air

[Dunderman]

As God is my witness, I had no idea where to put this thread. It does have to do with gaming so I'll put it here and see where it's moved to.

A roleplaying scenario of mine contains a castle (well, more of a fortified multi-storey bridge). The setting contains a fair number of creatures that can fly, so the castle's builders would obviously have considered that when building it. I've done a few things with it, such as putting locked steel cages around stairwells leading down off the roof and have covered areas with murderholes on the roof.

Anyone got any cool ideas for what else one could do to protect a castle against flyers? We're not talking dragons, but mainly winged humanoids. Regular armies, just attacking from above.

[Chimera]

Ballistae, Scorpions, Archers. The key to any aerial defense.

Lots of watch points to watch the sky.

Spellcasters with long range spells for interception. If you're talking D&D, then first and foremost, Fireball with it's extremely long range. Then you move down the line. Sound Burst, although short range, is awesome against flyers (stunned = falling). Wands of such spells in the hands of lower level 'guard' casters can be a great defense. Storm spells to make flying hazardous. Mist/Fog spells can confound flyers. Illusions can be even better for that if you can cover enough territory, making a solid tower or wall disappear.

*smack*
Whoops, failed to see the the invisible wall, did we?

[CalMeacham]

Standard castles were designed to protect against assaults from people and devices that were confined to the ground. They didn't have to deal with attacks from the air (thrown objects are something else altogether), and so they're not really built for it.

If you are faced with a situation where you have winged humamnoids capable of short slow controlled flight, yiou wouldn't build a castle that looked like a standard castle. You'd build it to defend against that bthreat as well. I wiould imagine that you'd have completely enclosed roofs, possibly strong and heavy domes with loopholes in them -- locked staircases be damned. I'd no more put an accessible opening on my roof under those circumstances than I'd put an unguarded door in the side of a standard castle. Any openings (and there'd be some -- you have to deal with interlopers, allow for passage on flying envoys, and the like) would be well-protected. There would be no unproptected or "blind" spots, just as in the perimeter of a standard castle. So my roof would bristle with ridges and extensions to "fill in" blind spots, and be fitted with loopholes for firing at the Flying Monkeys (or whatever they are).

[silenus]

In addition to the above, string lots of very sharp, very strong wire between every highpoint and the next. Make any attempt to land like flying through an egg slicer.

[Scuba_Ben]

Originally Posted by Chimera

*smack*
Whoops, failed to see the the invisible wall, did we?

Inevitable:

Originally Posted by Time Bandits

So THAT's what an invisible barrier looks like.

I disagree with the seige engines, as their rate of fire is too slow. I'd use lots of archers and put a lot of arrows in the air. Also have an air-to-air response team in the fortress; depending on the situation, the defenders may have some personnel (monsterrel?) on 5-minute alert.

[puppygod]

Originally Posted by silenus

In addition to the above, string lots of very sharp, very strong wire between every highpoint and the next. Make any attempt to land like flying through an egg slicer.

And a lot of spikes. I mean, there should be virtually no free space to land. Roofs should be steep and there should be a lot of spikes or blades on poles sticking out of every possible place.

Also, everything fireproof. No wooden buildings. Roofs should be constructed in a way that burning oil and other such things would stream down outside walls.

Instead of putting loopholes or whatever they are called in the roof (thus allowing invaders to throw firebombs or even make entrance), rather place several towers with crews of archers, placed so they could cover all roofs and weak points.

ETA - oh, and nets. Lots of nets between towers and high poles.

[Tuckerfan]

Given that ballista's were typically built with pivots, I'd think that mounting those on the roof would work quite well against flying monkeys.

[Madd Maxx]

Banana cannons. To distract the flying monkeys. Maybe a wizard or six with some air elemental spells. To keep other flying primates distracted.

[appleciders]

Why is a bridge being fortified if there's so darn many flying creatures around?

Ok, so if there are flying creatures and we're protecting a bridge anyway, there must be a sizable contingent of non-flying creatures. Don't neglect this in favor of the new coolness. Personally, if I had those flyers, I easily might try not to conquer the castle from the top but rather provide cover from archers, spellcasters, and other ranged types for my ground army- it's going to be comparatively easier for a flyer to force defenders to keep their heads down rather than actually assaulting. I think arrow slits, possibly with flameproof shutters (or, though I hate them unbelievably, some big armored Venetian blinds to prevent return fire while reloading) on the front face of the castle will be essential- very difficult to fire into but easy to pepper approaching forces from. However, watch out for incendiaries being thrown into them- flyers could do that easily and your castle may not burn but your defenders might die. Since this is a bridge/castle defense (can you get any luckier?) line your heavy siege equipment (ballistae, catapults, etc) up so they fire along the bridge approach to the castle. They'll do massive damage to approaching troops who are forced to approach straight and level and all in the same direction. This equipment is probably too heavy, inaccurate, and slow to reload to be effective against flying troops, so don't even bother. Possible exception- load the catapults with the equivalent of grapeshot; hundreds of small stones or darts. Accuracy is less important that way.

Razor wire spiderwebs, nets, and booby traps on the roof might be very effective. Spellwise, if there's some kind of summoner or beastmaster around, look to spiders, maybe cats. Bear in mind that flyers do not have to and probably will not attack from the same direction as the ground troops. Troops out on top of walls and towers that might have been safe before are now giant undefended targets. Flying troops are probably not using heavy plate armor due to the drastic decrease in manueverability- light mail or leather at the outside. As such, weaker projectiles might work as well as strong ones. Don't try to fight them in the air or the open- force them to come inside, to you, where their light armor (and wings, if applicable) are a penalty, not an asset.

Above all, build steep roofs and keep all staircases leading downwards indoors where you can use them safely away from the enemies and they can't get downwards without fighting you inside.

[Zsofia]

There's also the popular build-entirely-into-the-mountain Revelstone approach.

[Gukumatz]

Well, let's presume you're looking at a medieval-type D&D scenario;

Non-magic protection;

Archers and crossbowmen with pavise shields. Since crenellations will be almost useless against enemies who are - presumably - above you, fitting your archers with pavise shields to be strapped over their backs allows them safe havens from which to reload.

Catapults loaded with shredding materials - shale, sharp stones, etc. These will be effective to deny congengrations of enemies and keep them moving.

Ballistae, mysorean-style rocket artillery, crenelation-based lightweight catapults, heavy crossbows and - don't laugh - fireworks. These serve the function of striking at the enemies who stay at long range in a bombard-fashion.

Magic defenses;

Wizards with all slots used for fireballs, chain lightning and magic missiles. The fireball spell travels too quickly to be avoided and immolates enemies in a great area, the chain lightning jumps from enemy to enemy while the magic missiles can't be dodged. Prepare wands of these spells for non-sorceric defenders.

Clerics with group-healing type spells. Presumably the enemy will not attack in a melée and as such will rely on bows and speed to do their initial (light) damage. Group healing will keep these wounds patched.

Distractions - like Illusory dragons - can also be effective in keeping the enemy at bays, as can tangling spells like Web and Moss Web. Druids can also be a great help here, with their ability to call natural familiars in the form of seabirds, wasps and so forth.

Structural defences;

The essential thing is to make sure all vital passages are indoors, so one gains an equal footing if the enemy comes inside. Further, the main keep of the castle should be a tall and rounded building without an opportunity for cover from the wall-based archers and with no possibility for top-down entry.

Crenellations on the walls should be interspaced with archery stations in the form of a two-sided wall and roof, so archers can work both ways without their backs being exposed. The walls are interspaced with archery slits and one can keep amunition in them. The entrances of these can be protected with caltrops, netting, barbed wire or firewalls to keep enemy assaillants from skirmishing against them.

Ground melée troops should be kept from congengrating inside the castle grounds until the surface component of the enemy arrives at the walls because of the large potential for aerial bombardment (magical and bomb-based). Healing stations for the group-healing clerics should be clearly denoted and rehearsed. Here one might suggest underground bunkers (not connected with the main keep underground) so that the melée warriors might be protected until they have to defend the walls.


However, martial preparation aside, the most important factor is to drill the troops against such an assault and to devise a step-by-step retreat into the keep proper, in which the enemy troops have to chase you in on foot.

[duality72]

Originally Posted by Gukumatz

Catapults loaded with shredding materials - shale, sharp stones, etc. These will be effective to deny congengrations of enemies and keep them moving.

Interesting. This makes me think of grapeshot for a cannon which leads me to think of chainshot and grapple shot as two more possibilities.

[Lightray]

Camouflage netting or somesuch over the entire castle. You don't want the enemy flying recon to see what you're doing with your troops, you don't want the flying enemy attackers to see where you've positioned your troops when they're approaching, and you don't want the flying enemy attackers to be able to figure out what is a safe landing zone or kill-zone within your castle.

[Dunderman]

Originally Posted by appleciders

Why is a bridge being fortified if there's so darn many flying creatures around?

Well, a) because there aren't darn many of them but still enough that you have to think about it, b) because the bridge started out as an ordinary bridge, then got built up, used as a residence and eventually fortified because its residents now had other reasons to defend it than it being a bridge, and c) because I want it to be in the way of my players, none of whom can fly (suckers). I don't want to overthink it, just add a touch or three. We're geeks, but we're also big fans of willing suspension of disbelief.

Wires, spikes and blades are excellent suggestions, thanks. Powerful magic is rare, so it's not something you plan using or defending against.

I'm thinking about what to do with those stairwells, though. Access points to the roof is needed, but I guess a heavy trapdoor locked from the inside is a better solution than my original one.

[Left Hand of Dorkness]

Is there any place in such a defense for noxious smoke? If you can fill the air above the castle very quickly with smoke, you can make an aerial assault much more difficult. I'm not sure if that could be effective, though.

Daniel

[Darth Nader]

Lose the battle. Dig deep next time.

[Apollyon]

Completely agree with the sentiment of building something other than a traditional style castle... but, depending on the magic available, you could go for something like this Castle Defense System that appeared in the DragonQuest campaign I play in.

(First encountered one while on a flying boat... not pretty...)

[The King of Soup]

Float balloons filled with flammable gas and short fuses attached. That's just for fun.

Up top, smudge pots on poles -- flying humanoids hate not being able to breathe or see. If your world includes plants that when burned might addle someone, throw 'em on the fire as well.

Be aware of their limitations. I hope your castle has narrow passageways. Humanoids with wings are going to be wide and bulky proportional to their strength, pretty much all of their muscle has to be devoted to beating their wings, and they can't support much meat and bone elsewhere. They won't be able to carry much, certainly nothing heavy in the way of weapons, and if they land, they're a meal in a bucket. They'll have to stop and feed incredibly frequently, which means your land-based cavalry can stop them just by attacking the enemy's supply lines. Can you make rain? Practically no naturally flying creature ventures out in a downpour. You can make steam: you may be able to discourage them with incredible humidity.

A good falconer might be able to encourage his birds to harass the larger attackers the way smaller birds, in concert, attack his raptors.

Mostly, just don't let your opponent get away with pretending that a flying army costs the same as a walking one. They eat more, fight less, carry practically nothing and are useless if forced to defend a fixed position.

I have no idea at all what I'm talking about. I don't even play these games. But it seemed like a fun question and I hope I haven't wasted your time.

[BrainGlutton]

The best way is to have a castle in the air.

[Apollyon]

Originally Posted by BrainGlutton

The best way is to have a castle in the air.

Call me Mr. Silly... but wouldn't a flying castle be equally vulnerable to flying troops?
(While of course being well protected again ground troops).

[Apollyon]

Originally Posted by The King of Soup

Mostly, just don't let your opponent get away with pretending that a flying army costs the same as a walking one. They eat more, fight less, carry practically nothing and are useless if forced to defend a fixed position.

They are pretty certain to cost more regardless of the technology or magic being used to achieve flight, but the amount they can carry and their fighting abilities are very much dependent.

Flying humanoids (bat-winged guys, or angelic types) -- assuming the physics can support them getting airborne -- are likely to be lightweight and even fragile.

If the tech or magic is more like jet-packs, then they weight carried may be constrained, and the troops lightly armed, but the troops themselves of normal capabilities once they land.

If flying carpets, flying boats, etc are available then both heavy troops and equipment might be flown in.

But yes, they're likely to be terribly expensive / rare.

[Mosier]

Originally Posted by Priceguy

Well, a) because there aren't darn many of them but still enough that you have to think about it, b) because the bridge started out as an ordinary bridge, then got built up, used as a residence and eventually fortified because its residents now had other reasons to defend it than it being a bridge, and c) because I want it to be in the way of my players, none of whom can fly (suckers). I don't want to overthink it, just add a touch or three. We're geeks, but we're also big fans of willing suspension of disbelief.

Wires, spikes and blades are excellent suggestions, thanks. Powerful magic is rare, so it's not something you plan using or defending against.

I'm thinking about what to do with those stairwells, though. Access points to the roof is needed, but I guess a heavy trapdoor locked from the inside is a better solution than my original one.

How do the flying things attack? Do they land on the roof and duke it out with hand to hand weapons, or shoot arrows or something?

You can toss a lot of shrapnel and debris in the air with something like a catapult. The people operating it could be protected by a cubby built into the sides of the machine. Load the shrapnel, arm the machine, let the stuff fly, and duck into the cubbies before the junk hits the ground. That would be a good way to stop flying troops of the "shoot arrows" or "swarm" variety.

If they have to land before engaging in battle, a small group of soldiers with a couple of long spears could make landing extremely difficult. If they're spaced out correctly, even a small group could quickly bring lots of pointy edges to bear against a descending enemy, since you dont have the normal "bottleneck" problem if you're aiming at something in the air. Flying things take up a lot more space relative to their size and strength, meaning there's a whole lot of places to stick a spear and cripple them.

[The King of Soup]

Hi, Apollyon -- good to meet you. Please accept my best regards and wishes.

The OP did say (didn't he? I think so) winged humanoids -- as I said, I don't play these games and probably shouldn't be allowed to discuss them -- but to me, wings means certain limitations. Out-and-out magic doesn't, and to my constricted imagination, that's why it's out of bounds. Otherwise, the game devolves into "Oh, yeah? Well, my wizard can do this!!!" And where's the fun in that?

But I'll bow to your ideas -- obviously you've thought about this much more than I did before posting.

[Apollyon]

Originally Posted by The King of Soup

Hi, Apollyon -- good to meet you. Please accept my best regards and wishes.

Good to meet you too King of Soup.

The OP did say (didn't he? I think so) winged humanoids...

Ahhh... Yes.... or at least "mainly winged humanoids"... and he later mentioned that "powerful magic is rare"... so your comments on cost, weight and fighting ability are probably rather more germane than mine,

...as I said, I don't play these games and probably shouldn't be allowed to discuss them

Pish, and indeed tosh! Priceguy hasn't specified a particular game system (or even confirmed an exact genre), so I think we can all play this thought experiment. Some of the other posters have mentioned D&D in their answers, most of my experience with this sort of thing has ome from DragonQuest (which has a fair amount of flight magic -- probably rather more and more powerful than what Priceguy is referring to.

...to me, wings means certain limitations.

And is probably much closer to what the OP is after... something like the Garuda of Miéville's Bas-Leg (Perdido Street Station, etc).

Out-and-out magic doesn't, and to my constricted imagination, that's why it's out of bounds.

I understand what you are getting at -- my wife's main rpg fantasy character is a winged halfling (didn't start out with wings -- long story), and while it might in fact require a magical world (or at least one with different physics to our own) to get a 3' 6" halfling off the grounbd with 7' angel wings, it's better to treat it as "natural" flight (like Pegasus, or a gryphon, etc) and then apply as much commonsense / real world knowledge as possible.

Otherwise, the game devolves into "Oh, yeah? Well, my wizard can do this!!!" And where's the fun in that?

Even when there is high magic in a game it will (usually) have rules around it... or a GM/Referee to say "no, your wizard can't"... but in review the OP does appear to be asking more about "natural" flyers than flying boats or carpets.

[Dunderman]

Originally Posted by Mosier

How do the flying things attack? Do they land on the roof and duke it out with hand to hand weapons, or shoot arrows or something?

They do whatever seems it might work. Imagine if someone gave you a pair of wings and the energy to use them efficiently, without having to worry about your skeleton becoming hollow or your food requirements increasing or your chest muscles needing to be made of steel. I don't go for realism in my fantasy games so I don't worry about what flying humanoids would require in real life, while simultaneously avoiding King of Soup's "My wizard can do this!"; I have set rules that everyone knows about but that nevertheless are ultimately extracted from my posterior orifice.

In short, if a force of the flying guys think they can attack effectively with bows and guns from the air, they will. If they think they can do so by landing and swinging swords, they will. This is not a big concern - there are two races of flyers, both uncommon and neither inclined to form huge armies - but big enough that you would put some thought into it when building a castle. The flyers have had decisive effects on historical battles, so it's something to think of.

[Apollyon]

Originally Posted by Priceguy

I have set rules that everyone knows about but that nevertheless are ultimately extracted from my posterior orifice.

Or, to use the technical term, an indie game.

[The King of Soup]

Originally Posted by Apollyon

Good to meet you too King of Soup....

Thanks.

I have the uncomfortable feeling of having given offense without intending it. I am aware that lots of people have invested lots of time and thought and effort into exactly the sort of question the OP asked, and I am embarrassed to have used the word "magic" disparagingly, meaning (for my own purposes) "without rules" when for most of the people who play and think seriously about these things, it merely evokes a whole new, complicated and strict set of rules that I haven't thought about and don't understand. I sincerely apologize to anyone who felt or feels slighted by my remarks.

Still, from Twain's Connecticut Yankee on, I've always enjoyed the rude collision of reality with fantasy, and that's all I was trying to get at in my first post. Peace.

[mswas]

Peaked Roof with a steep slope, buttressed from the inside creating a multilayered honeycomb shape, that has multiple levels woven into it. Around the bottom of the slope of the peak where it levels off there is a battlement with giant spikes sticking out, so if aerial troops every tried to land they'd be impaled. Along the battlement are archers that can shoot things down, hopefully on the roof to be impaled by said spikes.

Oh yeah, and fluted shapes to guide rocks to particular exit points in the battlement to rain down on any sieging army below in case the fliers decide to drop rocks on the castle.

[MrDibble]

Originally Posted by silenus

In addition to the above, string lots of very sharp, very strong wire between every highpoint and the next. Make any attempt to land like flying through an egg slicer.

This solution (on a certain other world this is known as tarnwire) would be my first recourse, too.

Also, having some flying troops of your own, to meet them on equal terms. At the very least, poison your falcons' claws.

[puppygod]

Originally Posted by Left Hand of Dorkness

Is there any place in such a defense for noxious smoke? If you can fill the air above the castle very quickly with smoke, you can make an aerial assault much more difficult. I'm not sure if that could be effective, though.

Daniel

Very good idea. A couple of strategically placed cauldrons full of burning tar coupled with all that wires, poles and nettings could effectively make any kind of aerial assault suicidal.

Lets see, what kind of threat could flyers be:

Intel. To prevent them from scouting, all that camo netting (as proposed by Lightray), smoke screens and putting everything possible under the roof should be enough. Also, if flyers can't see in dark, do maintenance and moving defenders / changing arrangement of defenses at night. Keep them guessing.

High altitude bombing attacks. Make everything fireproof. As much roofing as possible, with significant overhang. Actually, now that I think about it, design similiar to japanese castle would be quite effective. Not many options of counterattack though. Possibly catapults or other siege machines could launch buckets of small stones far enough to reach attackers.

Low altitude bombing / attacking with ranged weapons / skirmishing. Here comes almost everything we had in this thread. Smokescreens, nets and wires, fireworks. Lots and lots of archers.Actually, if all these defenses ar ready, then attackers are at serious disadvantage at that range. They can't use heavy shields of armors, they have only limited number of projectiles on them, they can't use terrain to hide, they need to watch if there is some net in their path etc. Meanwhile defenders can concentrate on making pincushions from flyers.

Landing and direct assault. Again - nets, roofs with spikes, forest of poles where there is no roof. Make them impale themselves during landing. Also placing archers on towers that overlook whole castle. Most defenses here are in design. Leave no opening. Where you need entrance, make it heavy doors, possibly doubled. Should be enough - they can take battering ram with them, so can't really break through solid doors. Oh, and if some windows are large enough for humanoid to fit, put some gratings in them.

Overall, with enough archers and proper design of castle, aerial troops can't do much beside scouting, correcting artillery fire from safe distance and drawing defenders attention away during critical moments of assault.

[Apollyon]

Originally Posted by The King of Soup

I have the uncomfortable feeling of having given offense without intending it.

Nothing that you wrote could or did offend me in any way, shape, or form. (If I am who you are concerned about). Cheers, Apollyon.

[Quercus]

OK, I can’t believe I’m spending precious brain energy thinking about this, but here’s my thoughts:

I’m assuming that the threat is flying humanoids as part of a larger army with lots of ground troops, so you’ll still want traditional high stone walls.

Then, basically, treat the roofs the same way castles treat the outer walls: put stone between you and the attacker, and make sure that every outside edge of stone can be fired on by a defender. The fighting areas on top of the curtain walls will be roofed with stone, and have walls on the front and rear with loopholes to shoot through. Towers on the ends of the walls would allow fire on the roof of the wall. The tower’s fighting platform is also roofed in stone, with two turrents sticking up that can cover the tower’s roof as well as each other’s roofs. The roofs of the great hall or whatever would all be slightly below the level of a tower in the corner that can fire down on the main roof.

For castles that aren’t already all connected (for instance, the classic double ring of curtain walls), you’d have to have covered ways connecting them so troops can advance or retreat without being exposed from above. You’d have to make sure the ways are still exposed to fire from the inner walls, so attackers can’t use them for shelter if the outer wall is abandoned.

If for some reason you need a doorway to the roof, you do it the same way as the gates on the ground: the doorway is set back (in this case, down), so the door is covered by fire from the walls on either side. And probably, behind the door, there’s a stairway down ending in another strong door, again surrounded by walls with holes so that defenders on the other side can do nasty things to anyone trying to force open the second door.

You would want some kind of sally-port in case the defenders have enough flyers to match up with the attackers, but that could just be a door into a courtyard, not necessarily to the roof.

Roofs would all have drainage arranged so that noxious liquids (burning oil, essence of rotting animal, etc.) would be directed to safe places. Ideally roofs would also all be steep and slippery, but it’s more important that they be covered by missle fire. Slanted roofs to help deflect medium-sized rocks might be useful. If the enemy has a captive roc or large dragon that can drop very large rocks on the castle, then you do what real-life castles did when the attackers managed to build a giant trebuchet: either counter-attack to take it out before it gets used, or surrender.

I don’t think spikes would be very useful in most cases: flyers can just hover and put their foot down carefully next to the spike. And, historically, metal was way too expensive to use that way. After all, if metal was that cheap, real castles would have covered the ground approaches with spikes and barbed wire. But historically scarce metal was best put towards more arrowheads. Wire might be useful to protect a small key area, but mostly I think it would get in the way of defender’s fire as much as anything else (though I’m assuming attackers can hover or fly slowly. If you know they’re limited to fairly high speed flight, then wires and barrage balloons start making some sense).

I do like the idea of noxious fumes, though the vision obscuring effects of smoke generally hurt the defenders more than the attackers.

[puppygod]

Well, the main purpose of all that netting, spikes and wires is to make flyers hover or fly slowly. Then instead of fast and hard to hit they become big, stationary, exposed targets.

ETA - I seem to remember reading about some kind of temple or palace (in Thailand? somewhere in Asia) with roof actually covered with metal spikes. Does somebody remember that one?

[duality72]

Originally Posted by The King of Soup

I have no idea at all what I'm talking about. I don't even play these games.

Sounds like you should.

[silenus]

Originally Posted by MrDibble

This solution (on a certain other world this is known as tarnwire) would be my first recourse, too.

Also, having some flying troops of your own, to meet them on equal terms. At the very least, poison your falcons' claws.

Few people are willing to admit they call it "tarnwire," for obvious reasons.

[Atrael]

While I don't know that I can add anything to what everyone else is adding, one thing did pop into my head when I read the OP and thought about the structure.

You said it was a bridge that was built up and fortified, right? Well how are you protecting the underside of the bridge? What about the support structures? Why bother storming the castle if I can bring down the whole thing by taking out two supports underneath it? Especially if the defenders haven't put any sort of defense against that in place.

[Really Not All That Bright]

You'd never hit a moving aerial target with a ballista. Hard enough to hit a ship with one.

[Dunderman]

Originally Posted by Atrael

You said it was a bridge that was built up and fortified, right? Well how are you protecting the underside of the bridge? What about the support structures? Why bother storming the castle if I can bring down the whole thing by taking out two supports underneath it? Especially if the defenders haven't put any sort of defense against that in place.

Well, it's pretty difficult to get close enough to do that, and there are cannon batteries, murder holes et cetera in place.

[appleciders]

Originally Posted by Priceguy

Well, it's pretty difficult to get close enough to do that, and there are cannon batteries, murder holes et cetera in place.

Shouldn't matter, should it? Destroying the bridge would be a net gain for the defenders, who would rather see the bridge destroyed than taken.

I love the idea of fireworks. That'd be a huge disruption and deterrent, especially at range. However, smokescreens would be a gain for the attackers, wouldn't it? Making it tough to spot the incoming attack.

[Sage Rat]

Probably what I would do would be to build the castle into the side of a cliff. Construction would mostly consist of boring, rather than building.

On Earth, this probably wouldn't be practical since you'd need light, but lots of fires would smoke the whole place up. But with magic, you could presumably use some sort of magical light source, and have just a few fireplaces with chimneys that ran to the surface for cooking.

[Bosda Di'Chi of Tricor]

Five or six Permanent-ized Invisible Force Walls above the castle, at angles to each other (spell names in italics). Midair collisions would be as deadly as catapult stones.

One such wall, directly above the castle, parallel to the ground, to protect against dropped weapons.

Dome-shaped castles, yes.

Early warning counts!!--Remote observers, away from the castle, in watchtowers. Drums, flags & signal fires to warn of incoming air raids or armies.

[Chimera]

For all the talk of wire, I have to point out that significant lengths of wire are pretty much an artifact of modern technology.

And the whole idea of lobbing stones upward at the flying enemy? Limited at best. They will lose significant kinetic energy flying upward. Then they come back down...

No, I think I'm really liking the idea of limiting exterior access and landing spots (severely sloped roofs anyone?) combined with heavy coverage from well protected archers.

[appleciders]

Originally Posted by Chimera

For all the talk of wire, I have to point out that significant lengths of wire are pretty much an artifact of modern technology.

And the whole idea of lobbing stones upward at the flying enemy? Limited at best. They will lose significant kinetic energy flying upward. Then they come back down...

No, I think I'm really liking the idea of limiting exterior access and landing spots (severely sloped roofs anyone?) combined with heavy coverage from well protected archers.

You realize that your arrows are going to lose kinetic energy and come right back down too, right?

You're right about wire being modern, but some decent cord (maybe magically reinforced) would provide a significant obstacle, even if it wouldn't cut.

If I were defending that castle, I'd be tempted to grease those sloping roofs to make them even more difficult to land on. Then again, if I'm attacking a castle with greased roofs, I'm probably going to try to light those roofs on fire. This could work against either side- hot flaming grease is going to run right off the roof, onto the head of those below if your drainage is good. However, it could, you know, burn down your castle.

[Chimera]

Originally Posted by appleciders

You realize that your arrows are going to lose kinetic energy and come right back down too, right?

Well yes, but they are potentially going to stick into their targets, not just bounce off like stones. They also have a lot less mass, which means a lot less kinetic energy when they come down. Sure, there's the whole "pointy" thing on the way down, but we just make sure no one's having a picnic in the courtyard during the battle, eh?

Don't grease the roofs, just make them naturally slick with nothing to hold onto, along with the severe slope.

[smiling bandit]

I'm curious as to how much these flying creatures can carry. There's going to be little point if the attackers can drop ten-ton boulders from a thousand feet up.

[Ranchoth]

I was thinking barage ballons, for starters—with, of course, the obvious problems that a) You may not have balloon technology, b) The attackers could shred the balloons, to take down the cables and/or nets strung between them, and c) they could simply fly above the balloons and attack from any gaps from above.

They may come in handy if—like Disney's Gargoyles—the winged humanoids can't actually make powered flight, but have to glide, which could limit their ability to climb to altitude for the attack.

Though I see King of Soup technically beat me to the balloon concept...and smudge pots. Filthy bastard. ( ) Some ancient chemical warfare techniques, such as burning mustard or sulfur, might be handy, too. Assuming you don't have any sentimental moral qualms.

Depending on the technology you have available, you might try something like a Fire-lance, an early Chinese gunpowder weapon. Kind of like a primitive fougasse/blunderbuss. (The very cool book Gunpowder has some good info on these, pages 13-15.) Supposedly, they could project a six-foot tongue of gunpowder-fueled flame that would burn for five minutes, additionally with bits of shrapnel (such as metal or crockery bits) mixed in with the powder to be spewed out.

Hell, a Punt gun would be good, too...if it's getting too steampunk-y, maybe you could rig up one powered by springs, or magic, or a big troll mercenary using one like a blowgun, or something.

Or you could buy some sick poultry from a disreputable Kara-tur importer, and try to give ol' Voltan bird flu.

[Chimera]

Originally Posted by smiling bandit

I'm curious as to how much these flying creatures can carry. There's going to be little point if the attackers can drop ten-ton boulders from a thousand feet up.

Depends on how good their bomb sight technology is.

[drachillix]

Originally Posted by Madd Maxx

Banana cannons. To distract the flying monkeys. Maybe a wizard or six with some air elemental spells. To keep other flying primates distracted.

considering this is a fantasy rpg type setting, especially if you want some kind of cool rescue, bailout situation would be flying reinforcements of your own, air elementals, giant eagles, djinn, pegasi, various demons, etc.

Spellcasters will also be of immense help via the fact that spells often lack the inaccuracy of weapon fire and even some lower level spells like sleep could be used with devastating effect on a flying critter.

[MrDibble]

Originally Posted by smiling bandit

I'm curious as to how much these flying creatures can carry.

Do you mean, like, could they carry a .. coconut?

[Sublight]

Man, I'm glad my D&D GM didn't think of these for his game. He put us in a small province sitting in between two huge armies: one led by a homicidal maniac baron who was pissed off at our group in particular and this town for giving us aid (so we humiliated him by stealing an ancient artifact he was completely unaware of that had been sitting under his castle for centuries, setting the central market on fire, kidnapping his second-in-command, and blowing the front gates sky-high in making our escape. Is that any reason to be a sorehead?). The other was ostensibly an ally of the province who was waiting for an excuse to swoop in an put them under permanent "protection". I think the GM expected us to either try and negotiate a peace, or flee with our McGuffin to the next stage of our quest.

As thief, I had the best sneak and snoop abilities, so our mage cast invisibility and fly (so I could get to the enemy camp and back before the invisibility wore off) on me so I could check out what we were up against. I found the Baron's tent and his main strategy center, checked out how many and what kind of troops he had, then buggered off.

We were mulling over what to do when suddenly it hit me:
"Hey, you can cast fly!"
(mage) "Yeah."
"And you've got more fireball spells than you know what to do with."
"uh... yeah" (this was a sore point with him. The market immolation mentioned above was unintentional)
"Nuke them from orbit!"

We waited until nightfall and managed to fly over the enemy camp undetected. After re-locating the Baron's tent we unleashed a high-altitude bombing campaign (in addition to the mage's spells, he'd also already made several wands of fireball) right on the command center that killed most of the leaders (though not the Baron), destroyed their #1 fear weapon and threw everyone into disarray.

Final score: withdrawal of remaining troops by one now-extremely homicidal but impotent maniac Baron, reluctant withdrawal of troops by one "ally", one saved province, and one pissed-off GM.

He didn't learn his lesson, however, and we were later able to successfully besiege a castle using almost exactly the same strategy.