How much/how fast can a gelatinous cube "eat"?

[gadren]

So, in another thread, I've been talking about the castle that was a dungeon that the PCs have decided to take over as their own.
Last night, one of them came up with an idea. During the adventure in the ruined castle, they came across a room with a gelatinous cube in it. They decided it wasn't worth fighting, and just, shut the door and left it there.
Now they want to use it as a garbage disposal and septic tank. They want to make a glass-lined pit, 30 feet deep, 10 feet x 10 feet wide, lure the cube into it, and then when they attract followers to the castle via Leadership, use the cube as a way to dispose of leftover food, waste, etc. (basically all organic garbage).

I think the idea is brilliant, though it does raise a few questions not immediately answered in the monster description, and I was wondering if anyone knew of any Monster Ecology articles from Dragon or the WotC web archive or anywhere else that might have answered them:

1. How much can a cube "eat", and how long does it take? Basically, how much garbage can be poured into at a time? Could it handle digesting the waste of 100+ people a day?

2. How do cubes grow? They can advance to huge size, at least, according to the d20 srd. I'd assume that is from eating? How much does it have to eat to grow? Do you think they should possibly grow larger than huge?

3. Cubes don't have a climb speed and have no ranks in Climb. Does that mean it can be safely assumed that they won't climb out of a well-sealed pit made of material their acid can't dissolve?

4. Any other issues I should consider?

[OldTrees1]

Warning: I only used the Monster Description & the object hp section of the PHB

1) I think the Cube's acid works on everything it touches regardless of how fast it can eat. So I would calculate it based upon the acid damage & some fraction of the Cube's volume.

If we assume the Cube can work evenly on 125 cubic feet at a time and we assume that a common object will have less than 15hp, then we can expect it to be done in just over 4 rounds. So let's round and say it can handle 250 cubic feet per minute. How many castles did you say were using this septic tank?

3) I don't think the Cube would think to climb. Just to be safe make it hard to climb and keep it's food away from the edge.

4) "A gelatinous cube’s acid does not harm metal or stone." So be careful about the silverware.

[Ashtagon]

Make sure you have drainage holes. Just because the acid dissolves stuff, doesn't mean it turns stuff into nothing. The acid basically turns stuff into a slurry that can either be ingested by the cube of left to drain away into the ground. That's not normally a problem if the cube can wander around or if the ground is porous, but 'caged' like this, it could be an issue.

Organic waste (aka excrement) fed to the cube probably won't give it any nourishment. It'll still dissolve that stuff, but cubes have generally the same calorific nutrition requirements as any other animal. It'll pass through the cube like corn through you. The kitchen scraps from a garrison's kitchen would probably be enough to keep it healthy.

Regarding growth, there's no canonical answer to the question of how big an individual gets. Although rules for advancing their HD (and thereby size) exist, it has never been canonically stated whether individual examples of a species grow this way, or if advanced creatures indicate very similar species that differ only in adult size.

There is an ecology article in an old Dragon issue (from the pre-3e days) that suggests that a cube will split into two new cubes every 6-8 years. That's the only data on growth we have.

[gadren]

There is an ecology article in an old Dragon issue (from the pre-3e days) that suggests that a cube will split into two new cubes every 6-8 years. That's the only data on growth we have.

Do you by any chance know what the issue # was? Maybe I can find a PDF of it.

[MisterKaws]

Gelatinous Cubes actually feel rather comfortable inside holes as long as they're regularly fed, and are commonly used in pitfall traps.

If you want some more detailed info on them, try to get Dragon #124. I don't have it either, and my internet connection is too slow to use methods that would otherwise be illegal if my country's laws weren't so easy to circumvent, so I can't help you any further.

[gadren]

Gelatinous Cubes actually feel rather comfortable inside holes as long as they're regularly fed, and are commonly used in pitfall traps.

If you want some more detailed info on them, try to get Dragon #124. I don't have it either, and my internet is too slow to use methods that would otherwise be illegal if my country's laws weren't so easy to circumvent, so I can't help you any further.

Awesome, found it.

[gadren]

So, according to the Dragon article by Ed Greenwood, a gelatinous cube that eats an average amount grows and divides into multiple cubes about once every six years.
So, I guess the question is, how much an average amount of food is for a gelatinous cube.

Anyone want to make any estimates at how much mass a typical cube would get to consume per year?

[InvisibleBison]

So, according to the Dragon article by Ed Greenwood, a gelatinous cube that eats an average amount grows and divides into multiple cubes about once every six years.
So, I guess the question is, how much an average amount of food is for a gelatinous cube.

Anyone want to make any estimates at how much mass a typical cube would get to consume per year?

Well, elephants eat about 330 pounds of food per day. Gelatinous cubes weigh about 3 times as much as elephants, but they can also eat meat, which has a higher caloric density than plants. So assuming that cubes need 3 times as many calories, but eat higher-caloric density foods, maybe 600 to 1,000 pounds of food per day, depending on what exactly you're feeding it?

[Âmesang]

I was just thinking about gelatinous cubes today, oddly enough… except I was wondering if they could be divided and frozen solid with acid-proof Popsicle^® sticks, left in the ice box by some wizard who wanted to leave behind a nasty and silly trap for interlopers.

Pull out the sticks and watch 'em melt and reform into hungry lil' cubes…

[elonin]

Gadren, from the way you asked the question I'm guessing you are the dm and not the player. If that is the case then it works the way you say it works. Personally, I'd consider the damage they do and the food they can generally be expected to get which doesn't seem like much. So the idea of feeding it scraps and other refuse seems like a decent way of getting rid of the trash. Depending on the style of play at your table i'd suggest the party is slowly filling the pit anyway unless there is drainage of some sort.

[gadren]

Well, elephants eat about 330 pounds of food per day. Gelatinous cubes weigh about 3 times as much as elephants, but they can also eat meat, which has a higher caloric density than plants. So assuming that cubes need 3 times as many calories, but eat higher-caloric density foods, maybe 600 to 1,000 pounds of food per day, depending on what exactly you're feeding it?

Hmmm, that seems like a lot. I don't really see your typical cube successfully eating 4-7 people a day, every day.

Gadren, from the way you asked the question I'm guessing you are the dm and not the player. If that is the case then it works the way you say it works. Personally, I'd consider the damage they do and the food they can generally be expected to get which doesn't seem like much. So the idea of feeding it scraps and other refuse seems like a decent way of getting rid of the trash. Depending on the style of play at your table i'd suggest the party is slowly filling the pit anyway unless there is drainage of some sort.

Yes, I'm the the DM, and yes I'm aware that what I say goes. I just like to bounce ideas off of other people and see if something comes up I hadn't thought of.

[OldTrees1]

Hmmm, that seems like a lot. I don't really see your typical cube successfully eating 4-7 people a day, every day.

Adjust that value for:
1) Relative Activity. Elephants like to walk around. Cubes barely crawl.
2) Meaty flesh converts calories into movement, repair, & heat. Cubes only really need that first one.


I would calculate their food intake by considering the stereotypical (warning: this is subjective) dungeon environment. The cube would have a daily path across which it consumes microfauna, microflora, small plants, and vermin. Rarely a sentient will wander in and fall prey to the Cube. So maybe 1 bucket of nutritious organic material per day?

[gadren]

Perhaps it easiest to just say they eat the same as a horse, since that is something that already has rules in game. Cubes move considerably less and have fewer biological processes than horses, but cubes have much, much more mass despite both being large creatures, so I'll call it a wash.