Cube vs Square


Rules Questions


Ok, I am sure this has been asked before and I am probably dumb here, but this is something that got me. Why do spells like Mage's Magnificent mansion, a spell that makes a mansion, use cubic feet instead of square feet? Square feet is used to measure the area of a building. Cubic feet is for measuring volume. It baffles me why they are trying to measure the volume of a house.

I know there are other spells that use cubic feet and I don't have the mathematical knowledge to convert cubic feet to square feet, or even if that is doable. I know I could learn but putting that much work into something like that doesn't seem worth it.

I remember the group sitting around the table for almost half an hour, for one round of combat, trying to figure out how stone shape works in entombing a person with stone during a fight.

Liberty's Edge

Pathfinder Pathfinder Accessories Subscriber; Pathfinder Roleplaying Game Superscriber

I believe they use 10' cubes, which is about 1000 cubic feet, and is a cube 10' on a side, so matches up well with 10' squares, again rather than 10 square feet.


Volume allows you to include the height of the building as a calculation. 400 square feet gives you a 20x20 space on the floor -- but is it a 5' ceiling (2000 cubic feet), a 10' ceiling (4000 cubic feet), or a 50' ceiling (20,000 cubic feet)?

Easy calculation method: Figure every 10 cubic feet converts to a 1x1 square with a 10' ceiling (so 1000 cubic feet is 10x10x10 -- note that a lot of spells will just include "10' cube" as their basic volume unit, which is a bit easier to figure out).

Hence Mordenkainon's magnificent mansion" with three 10' cubes per level, could be conceptualized as "1 moderately large room per level of the caster" -- though the player might as well draw his own floorplan at this point.

Something like stone shape uses a lot fewer cubes, but the basic thought is that they want to be able to affect a small volume of stone, not everything from the top of Mt. Everest down to the core of the Earth.


1 person marked this as a favorite.

Square footage = Length X Width.
Cubic footage = Length X Width X Height

I think it becomes important when you start to consider creatures larger then medium size, flying, and storage of large items or large volumes of items.

For example, let's say you have a large sailing ship you want to store. The ship is 100 feet long, and 10 feat wide, so it has an approx 1,000 square foot "footprint". However, it also has large masts, let's say those are 100 feet tall as well.

Now, a 100' X 10' room with 10 foot high ceilings has enough "footprint" for the ship, however, the ship won't fit in a 10 foot high room. You only have 10,000 cubic feet. So you need the same room, except 100' high, which would be 100,000 cubic feet.

Last time I played a high level wizard, he was a conjurer, who enjoyed summoning Celestial Apes - A large (10x10x10) creature, with 10' reach, and a 30' climb speed. I designed Mezacal's Magnificent Monkey Mansion as a retirement home where all the large size celestial apes could climb, and move about freely. It might have smelled a little funny, but it was the least I could do after all the horrible stuff that happened to those poor summoned apes over the years.


I don't know, maybe because I use the metric system here. This reminds me of trying to figure out AD&D where spell ranges sometimes say 12' and yards.


Metric conversion


It's basically to help you account for "floors". Not everyone wants their mansion to be flat and spread out.


Claxon wrote:
It's basically to help you account for "floors". Not everyone wants their mansion to be flat and spread out.

And since the distance between floors is conventionally around ten feet, (i.e. a 20 story building is about 200 feet tall), the math works out pretty simply. That is if you're a 20th level wizard, you have 60 cubes to work with so you could have 6 stories of 20x50 square feet, or 10 stories of 20x30 square feet, or 2 stories of 60x50 square feet (or other combinations since 60 is divisible by a lot of stuff.)

Community / Forums / Pathfinder / Pathfinder First Edition / Rules Questions / Cube vs Square All Messageboards

Want to post a reply? Sign in.