How strong a hold can you fit in a Colossal space (30x30x30)?

[Morphic tide]

The most straightforward approach for sliding Stronghold spaces into a 30x30x30 cube is by their suggested 20x20x10 dimensions, which gives you a 20x20x30 "pillar" with two more spaces lain sideways, leaving quite some "noise". However, few Stronghold components are neat 4x4 squares of floorplan per space (almost all larger, granted), establishing flexibility in layout that can "soften" it to be volumetric instead of tiling.

This allows for cleaner implementations like two 15x25 "blocks" with corners taken out for a 10x5 "offshoot" to leave a 10x10 square between them for a stairwell. An oubliette-style prison cell or fortified ladder/stairwell "gate"house/guard post can work decently for filling the leftover space of that arrangement, or one that takes the 10x10 square out of the middle of each floor.

This does not necessarily need to make sense as the innards of a probably-Construct creature, this is simply about what can be done with a Stronghold bounded by that size of cube. Fancy houses, oddly-proportioned guard towers, small keeps, whatever nonsense comes to mind with that half-off on permanent spell effects for Magical Architecture, if it fits in the thirty-foot-to-a-side cube without flagrant violation of Stronghold Builder's Guide guidelines it's fine.

[Biggus]

Probably not what you're looking for, but: https://www.d20srd.org/srd/epic/monsters/livingVault.htm

[Maat Mons]

You could cover every bit of flat floor with an Enveloping Pit, to get a bunch of extra room to work with. Every flat piece of wall could have a door to a Magnificent Mansion, but unless your DM will allow the spell to be made into a permanent custom item, you'll have to keep recasting the spell every time it wears off. Dragon 299 had a magic Dollhouse that contained an extradimensional manor within it. Though, honestly, the most sensible option is to just use the stronghold to guard a portal to your own personal demiplane. Then it you effectively have unlimited internal space in a very small package.


Edit: Here are some possible floorplans for portal gatehouses.

https://thumbs2.imgbox.com/91/11/BkwxL3pb_t.jpg (https://images2.imgbox.com/94/d8/Z69ttH0P_o.jpg)
Click for full size.

https://thumbs2.imgbox.com/94/d8/Z69ttH0P_t.jpg (https://images2.imgbox.com/91/11/BkwxL3pb_o.jpg)
Click for full size.

[ShurikVch]

By the RAW, there is no limits for the Colossal size - supermassive star still would be Colossal (at least, if it's animated somehow - non-creatures are just may not count as a single object)

Thus, there are no limits for how much you can fit in a Colossal - as long as it is a creature of some kind (presumably, it would be Construct - but Outsider is possible too)

[Maat Mons]

It's been over a week, and I'm the only one who submitted a floor plan. That means I win.

Actually, since I submitted 2 floor plans, I win both 1st and 2nd place.

[shaikujin]

Ah, maximizing Stronghold Spaces!
I have some experience squeezing Stronghold Spaces into Ships and Enveloping Pits :D



Since the limit given is 30 x 30 x 30, cleanest way to fully utilize the space is by using the flexibility mentioned on page 11.

Paraphrased:
Master bedroom suite can be a 20-foot-by-20-foot room, an octagonal room 25 feet across, or a 15-foot-by-30-foot room.



Using the 15-foot-by-30-foot room we can have 2 Stronghold Spaces on each 10 foot floor. For a total of 6 stronghold spaces. No empty gaps. Use ladders or teleporters move between the floors.
Map of 1st Floor, with room 1 and room 2. Each grid is 5 x 5 ft. Same layout for 2nd and 3rd floor.


1
1
1
1
1
1


1
1
1
1
1
1


1
1
1
1
1
1


2
2
2
2
2
2


2
2
2
2
2
2


2
2
2
2
2
2




There are components that takes only 0.5 stronghold spaces: Bath, GateHouse, Guard Post, Office, Prison cell. So using the same 15 x 30 x 10 space, half the size would be 15 x 15 x 10. This layout provides 12 rooms. Sample map for each floor:


GH
GH
GH
GP
GP
GP


GH
GH
GH
GP
GP
GP


GH
GH
GH
GP
GP
GP


B
B
B
O
O
O


B
B
B
O
O
O


B
B
B
O
O
O




If it's just for maxing out stronghold components, we use the standard 20 x 20 x 10 sized rooms. 0.5 Stronghold Spaces will take 20 x 10 x 10 instead. Making something like this where rooms 1 to 4 can be Prison cells, and room 5 is a 2 storey Guardhouse. There will be an extra 10 x 10 ft above the 2 storey guardhouse that can be a 3rd storey. For a total of 13 components (4 normal 0.5 rooms, x 3 floors + 1 2-storey gatehouse). Map of each floor:


1
1
1
1
4
4


1
1
1
1
4
4


2
2
2
2
4
4


2
2
2
2
4
4


3
3
3
3
5
5


3
3
3
3
5
5



2 x 0.5 Stronghold spaces can be combined to give 1 Stonghold space if you want other larger types of components.

[Maat Mons]

How thick are you figuring the walls are? I went with 2.5 feet for mine, which already seems on the thing side for walls meant to repel invaders. That knocked me down to an internal floorspace of 25x25.

[Seerow]

Since stronghold spaces are largely an abstraction and can be reshaped to the desire of the builder, and the volume of the space is the important part of the cost, instead of trying to actually create a floorplan, I'd lean towards just doing a volume comparison.

Colossal Space is 30x30x30 = 27,000 cubic feet
1 SS is 20 x 20 x10 = 4,000 cubic feet.

27,000/4,000 = 6.75 SS in a Colossal Space.


That said the smallest stronghold space is .5, there are no .25 increment spaces, so without homebrewing best we'll get in 6.5, and the extra .25 can probably be chalked up to walls.

Coincidentally scrolling through the rest of the thread, that matches up with what people are getting from actually trying to do the layouts so seems fair.

[MaxiDuRaritry]

How thick are you figuring the walls are? I went with 2.5 feet for mine, which already seems on the thing side for walls meant to repel invaders. That knocked me down to an internal floorspace of 25x25.Wall of force (or riverine) has infinite tensile strength and can thus be infinitely thin, so the correct answer is "nigh-infinitely thin."

Note that riverine is technically non-magical, since it's a substance and not a spell effect, so it can be affected by (greater) (psionic) fabricate. Since that is the case, purchase 1 cp's worth of riverine and use fabricate (etc) to stretch it into all of the walls, ceilings, etc.

My suggestion is to start with a Colossal 30' cube, hit the entire place with a(n un)hallow effect tied to a spell that shrinks inhabitants down to Fine size, fabricate the walls (etc) into 10' cubes with Fine-sized doorways connecting them in the corners, cover all the walls, ceilings, and floors with enveloping pits, then fabricate the riverine to create whatever structures you like inside all of the resulting space. Magically enhance the riverine with immunity to things that destroy riverine so that it can no longer be fabricated to remove that weakness.

...And then make one itty bitty (disguised) portal hidden somewhere in the labyrinth that leads to your actual abode on your personal demiplane.

Bonus points if the only way to get in as a Small or larger creature is to teleport into a very specific space, which happens to be filled with Transdimensional quintessence, which traps any such creature in a timeless stasis. Craft or summon some critter or another that is immune to temporal effects to clean out the bodies of invaders by either tossing them in a demiplane that is itself filled with quintessence (if uninvited), or by pulling them out, shrinking them, and cleaning all the quintessence off to release them (if not).

[edit] You can actually get a lot more space than that, now that I think about it. If a Fine-sized human is, say, 1/4" tall, then having a number of stories each being about 1/3" tall would allow you to place enveloping pits on the ceilings and floors of each story, adding 100' of space for every 1/3" of actual space in the stronghold. That's significantly more than lining the walls, floors, and ceilings of 10' cubes.

[shaikujin]

How thick are you figuring the walls are? I went with 2.5 feet for mine, which already seems on the thing side for walls meant to repel invaders. That knocked me down to an internal floorspace of 25x25.

If force walls are too expensive, more convention lead-lined iron walls are 3 inches thick as per page 11. Created directly via Wall of Iron spells, or in tandem with the Fabricate spell to make modular bars that interlock with each other like Lego bricks. It will eat into the Storage Space, but 3 inches of external wall each side is still neligible compared to a room that is 10 feet at its narrowest part.