Need to create complex flying castles.

[GameDaddy]

What about using a new type of Glyph spell to imbue the stone or rock with buoyancy or anti-gravity properties?

Glyph of Warding Spell

How to use Glyph Spells properly;
http://www.llewellyn.com/journal/article/1355

 

[BlackSeed_Vash]

Stronghold Builder's Guide outlines how one can go about converting gold pieces into a castle, fortress, dungeon, or whatever else you can imagine. One of the many many options is to make parts or all of a stronghold Burrowing, Crawling, Flying, Sailing and/or Submersing. It's noted in the book that both Flying and Sailing do not actually provide locomotion without additional costs, the base price just allows the structures to float, one in the air the other on liquid it is built upon.

The way I've always look at magically enhanced rooms/buildings is applying the Craft Wondrous Items feat and whatever spell(s) make sense [Illithidbix makes several great suggestions]. The mortar could have special ingredients add, in the same manner holy water need silver dust, and infused with magic. There could be special runes hidden around their castles that mimic the spells embedded within an item.

 

[Greenfield]

How crazy can I get?

I'm thinking using Wall of Stone to create the Castle, then Polymorph Any Object to turn it into an adamantine castle. The Stronghold Builder's Guide might offer advice on how to make it fly, but I'm too lazy to read it. So how about we abuse an item casting Reverse Gravity to get it off the ground, and engines using Gust of Wind to provide propulsion?

Wall of Stone works. Poly Any Object doesn't: The spell has a volume of 100 cubic feet per caster level, which sounds like a lot, but when you consider that outer walls of a castle were typically 10 feet thick, then at 20th level you can affect a 10x 20 section of wall per casting. Add in that it can be dispelled. And, of course, the fact that it can't create Adamantine, or other intrinsically valuable material.

Because of the way the spell works, you can't affect a section of wall. You P.A.O an entire object, or nothing at all. Also, since the volume is in cubic feet, rather than a radius, feats like Widen Spell don't help.

Now Wall of Stone can be used cumulatively. At 20th level (you said you didn't want to go Epic), your wall is five inches thick and 20 5x5 sections in area. It attaches/embeds itself in surrounding stone, so you can glue layers together to make continuous surfaces.

Further you can shape it as you cast, so little details like murder holes, crenulations (the saw toothed look on the top of typical castle walls) and openings for doors and windows can be made, but that halves the volume of that casting.

Still, given enough time you should be able to build the fortress of your dreams.

Now, as for making the whole thing fly... You might consider enchanting it as a magic item, such as a Carpet of Flying. This is problematic though, since you wanted to avoid blind DM fiat. The castle far exceeds the weight limits of such an enchantment. There might be such rules in the Stronghold Builders guide, but straight item creation rules wouldn't cut it.

You could allw a *tiny* DM fiat by adding a spell like Overland Flight to the ones that can be grafted onto a Hallow spell. That spell makes an area or structure into a holy site, and lets you add one spell effect. The area is small (a 40 foot radius from casting point) but Widen Spell can help. Still small for an entire castle, but you're getting there.

That effect has to be renewed once a year, but that's not really an issue.

Want to make it really cool? Don't affix Overland Flight. Affix Wind Walk. The entire castle turns to vapor and flies at up to 60 mph, then re-materializes where you choose.

There are rules for crafting vehicles, such as ships that can sail over land, or that fly. Take a look at those, see if they lead anywhere.

Now if you just want it to float in one place, that's pretty easy: Fly to the appropriate location and use Force effects, like Wall of Force or Cube of Force, and make them permanent. (Some spells may not be on the normal list for Permanency, but Limited Wish can replicate the effect of that spell and bypass that limit. It has an Exp cost, but it always gets overridden by the cost of the Permanency itself: 500 Exp per spell level.)

Once you have a number of permanent force effects up in the sky, you bridge them with Wall of Stone or Wall of Iron to build the supporting undercarriage, expand to a stone foundation, and build your castle.

It's interesting to observe that many standard magic items, straight from the book, include abilities that can't be achieved with spells. For example, a Lyre of Building has an ability, once per day, that protects "all inanimate construction" within 300 feet from *ALL* damage. The protected walls, floors, whatever, are 100% indestructible for 30 minutes, and with a volume of a 600 foot diameter sphere it's just what the doctor ordered if you want your flying castle to survive that smash-landing you described. (It's possible to own several, so as to get longer periods of protection.)

Now comes the dirty trick: You want to stay strictly "by the book" in terms of spells, materials, etc. Custom spell research/design is in "the book". Reeks of DM fiat, I know, but it's there.

 

[Greenfield]

Okay, did the research.

Stronghold Builder's Guide section on mobile strongholds starts on Page 47.

Stronghold costs are based on "spaces", which describe how bit the place is.

A flying stronghold costs 15,000 gp per space. That allows floating only. Speed costs more. How much more?

Well if you want "incredible" speed of 10 mph it costs an extra 25,000 per space. That, by the way, is the top speed listed in the table. That translates to 14.666666666 feet per second, or 88 feet per round. Suddenly not looking so shabby.

Now you can modify this price based on the proximity of the nearest town or city. That's where workers come from. It's also who you have to get land from.

Best deal is to be about 20 miles from a small city. That saves you 2%. Might not seem like much, but if you're talking 40k per space, it adds up.

You can drop it by 10% if the site is in a "lawless area", meaning you may have to contest with monsters for the land, but not with any noble who wants his cut.

So how big is a "space"? By the book it's not a rigidly defined unit of measure, but generally every 20x20 of room with 10 feet of ceiling is a "space".

Table 1–4: Stronghold Sizes
Stronghold Type Size in Stronghold Spaces
Cottage 1
Simple house 4
Grand house 7
Mansion 15
Border tower 4
Keep 12
Castle 20
Huge castle 80
Small dungeon* 30–60
Medium dungeon** 60–120
Large dungeon† 120 and up

So your "Huge castle" is 80 spaces, times 40k, so the base price of the flying "huge castle" is 3,200,000 gp. That's the cost of making it fly with "incredible speed", not the cost of the castle itself. That part gets expensive, depending on what you want it to have,it terms of features, magical add ons and customizations, etc.

Build it on a hill, in lawless territory 20 miles from a small city, and you get a total 17% discount. That will let you shave off over half a million.

So, to answer the original question, yes you can do it. The stronghold is "epic" in the amount of money it costs, but not in terms of spells and/or caster-levels needed to buld it.

 

[The Human Target]

One suggestion.

Just because something is a flying fortress/castle doesn't mean it has to look like an earth bound fortress or castle.

One castle could be carved to look like a giant statue of one of the lords himself or herself.

One a huge dragon standing on its hind legs.

An enormous jade tree.

A collosal black metal fist.

 

[airistal]

Start with a adamantine pillar use what you need to get it airborne (plenty of options for that), then use it as an anchor for a lasting mordenkainen's magnificent mansion (quality of the anchoring method can allow for the other dimensional space to be seen into and out of). If extra size is desired an additional pillar setup and linking the extra dimensional spaces should suffice.

The impact damage will be equal to the pillar but will not affect the inhabitance of the castle due to it's extra dimensional status.

See Mordenkainen's magnificent mansion for spells details.

 

[NaturalZero]

I have a campaign setting based in a planet that is completely broken a part into floating masses of earth, so flying constructs are a large part of the world. If i were you, I'd trying to make each count's fortress as conceptually distinct as possible and worry less about whether they are immediately explainable by PHB spells.

Off the top of my head, I'd start with -

• A castle held aloft by floating soar whales. The fortress itself is a huge gondola below a "flock" of whales. The count uses enchantment or psionics to control the whales.
• A castle held aloft by jets and mechanical rotors. The core of the castle is a massive furnace that needs constant tending. This structure needs to land often to fuel.
• A castle formed inside magical, semi-solid clouds. This castle borrows directly from both cloud giant lore and folktales like Jack and the Beanstalk. The building might look like a storm front as it approaches and use lightning in battle.
• A castle formed from a swarm of massive, floating meteors. Geomancy animates a cluster of connected boulders and out-buildings of various size. This fortress can rain stones down to devastate enemies and gather earth from mountain in order to reform. Maybe the whole thing is a literal mountain.
• A city on the back of a flying turtle. Borrowing from the DnD zataran, this giant tortoise is the last of it's kind: a flying variety from the astral plane. The fortress is an entire city mounted on it's shell.
• A flying bubble of water. This fortress if formed from coral, suspending in space inside an enormous, floating zone of water. The entire structure is an aquatic lair with aquatic monsters.
• A ghost castle. This fortress exists partially in the ethereal plane, making it semi-solid and lighter than air. It comes to the ground, then fully shifts to the material plane.

The important thing is that make the things cool and memorable. You can always sit down and come up with super detailed and complex explanations for how they operate after you have a strong concept.

 

[NotAYakk]

The lyre of building plus extradimensional/teleport effects.

The smash has the castke being indestructible. The deziens less so. So remove them.

Arrays of bags of holding; one person can pull snother, who both pull another, who exponentially pull more.

The seed few who start the process need more expensive ways to survive the crash. A circle of teleportation to a land stronghold works.

Each bag is 10 minutes of air. This arguably can be extended with a bucket of water and a water breathing effect, but could be enough for a crash landing.

Tiny servants are another option. Or feather fall glyphs.

 

[dave2008]

1. I would build the castle normally. Their are various options to determine the cost, like Stongholds and Followers
2. Use magic to make it fly. Take some of the suggestions in post #10 , or others - there are lots of creative options, and extrapolate various rituals. A rule of thumb for making a spell permanent is to cast it every day for year. So assume a similar ritual takes a year (or perhaps multiple rituals to reduce the time) and the cost is the spell cost x 365 x area (number of castings need to included the whole castle in the area). This will get very costly very quickly!
3. Repeat step #2 as needed for the various things the castle needs to do: hover, fly, fall, etc. The same for means to strength the castle so it can slam into the ground.