Why does Enlarge Person make you so heavy?

[Gale]

I've been looking into ways to make a character larger when I ended up reading the spell description for Enlarge Person. It says it doubles your height and multiplies your weight by eight. In my opinion eight seems like a fairly large multiple to increase a person's weight by.
Let's take Halfings for example. They are a small race that weigh on average 30-35 lbs. with a height of about 3 ft. Using enlarge person on them would turn them into a 6 ft. creature who weighs about 240-280 lbs. That's a lot. A healthy six foot human male typically only weighs about 144-176 lbs. Thus, enlarge person makes you about 60% heavier than you would normally be if you were naturally twice as tall.
Ignoring the fact that it's "magic" I don't see the reasoning behind this. Can someone explain?

[cakellene]

Weght of muscle mass perhaps?

[JaronK]

You might want to look up the Square Cube law. If you double something's height (and increase everything else by the same proportion), you multiply their mass by 8.

Just basic math.

JaronK

[TaiLiu]

It's the square-cube law (http://en.wikipedia.org/wiki/Square-cube_law), I believe. Definitely strange in a world with literal giants, but, hey.

[holywhippet]

I assume it's because you become twice as tall, twice as wide and twice as thick. 2 X 2 X 2 = 8.

[broodax]

It multiplies your height by 2. But you're not a 1 dimensional being, you have width and depth too. These are also multiplied by 2. So overall your volume, hence your mass and weight are multiplied by 2x2x2=8.

You may be thinking that you're not a cube, you've got air inside you, curvy hips etc, but it's just a calculus problem to show you can be approximated by a near infinite number of cubes of stuff, and those are all multiplied by 8, so you are as a whole, too.

[Phelix-Mu]

They're going by the a pretty realistic metric for increases to one dimension and corresponding increases to volume. A person that is twice as tall, to remain proportional (and not look quite comical) is also twice as thick and twice as wide. 2x2x2=8. That's how that works.

The math is weird because halflings are actually kind of heavy to begin with, I think. Pretty sure human children are lighter than that, and fluff certainly makes many halflings out to be "well-rounded." Also *insert brief rant about how something 3' tall can't be as effective as halflings/gnomes can be*.

Also, height and weight are one of the areas where the simulation side of the game actually doesn't pay much attention. Jumping height and distance is pretty much the only place it really factors in much. Oh, and maybe squeezing rules...but I guess that is by size category...hmmm.

EDIT: Aaaaaand....overweight halfling'd.:smallsmile:

[eggynack]

(and increase everything else by the same proportion)
It's somewhat odd, but I'm not sure that there's any implication that this occurs. It's probably implicit in size alteration, but the explicit effects of the spell are only a doubling in height and an octupling in weight. There's no apparent commensurate increase in other vital surface area statistics. Perhaps the weight is meant to imply the other stat changes, but a strict density alteration could theoretically explain it as well.

[Greenish]

Let's take Halfings for example. They are a small race that weigh on average 30-35 lbs. with a height of about 3 ft. Using enlarge person on them would turn them into a 6 ft. creature who weighs about 240-280 lbs. That's a lot. A healthy six foot human male typically only weighs about 144-176 lbs. Thus, enlarge person makes you about 60% heavier than you would normally be if you were naturally twice as tall.Halflings are, relatively speaking, more robustly build, obviously. Fat little hobbitses…

[lsfreak]

Also as no one's answered the halfling part of the problem: it's because halflings don't make sense. (Of course, simply sizing up a person wouldn't work very well either, heart and lungs get comparatively weaker so you'll get winded faster assuming the heart is even capable of pumping the blood adequately enough to keep you from fainting, coordination would be thrown off by nerves taking longer to respond, etc).

[Phelix-Mu]

It's somewhat odd, but I'm not sure that there's any implication that this occurs. It's probably implicit in size alteration, but the explicit effects of the spell are only a doubling in height and an octupling in weight. There's no apparent commensurate increase in other vital surface area statistics. Perhaps the weight is meant to imply the other stat changes, but a strict density alteration could theoretically explain it as well.

If you doubled in height, but remained the same width and thickness, then a rather strange, feature-distorting effect would occur, which I'm going to call the "Stretch Armstrong Effect." Not only would it be comical, but it would probably bear mentioning this in the spell.

That said, I really do like the idea of using a density alteration to avoid suspension-exploding balloon people that can change mass at will...this aspect of transmutation always seemed funky to me (probably only because irl it's so implausible, but still).

[Greenish]

Also, height and weight are one of the areas where the simulation side of the game actually doesn't pay much attention. Jumping height and distance is pretty much the only place it really factors in much.Height and weight (separate from size categories) don't factor in to jumping at all. The height a medium creature can reach without jumping is 8', whether said creature is 4' tall or 8' (the limits of medium size category).

[Lord Vukodlak]

Usually you wouldn't use enlarge person on a small sized creature so they aren't the best examples.

I think they're trying to follow the Square-cube law, if you double something in size its volume increases by a factor of 8.

A cube with a side length of 1 meter has a surface area of 6m(squared) and a volume of 1m(cubed). If the dimensions of the cube were doubled, its surface area would be increased to 24m(squared) and its volume would be increased to 8m3. This principle applies to all solids.

So if you double someone in size in all dimensions you would increase the weight by a factor of eight. The trouble is a 6ft human may be twice the height of a 3ft halfling but he's not quite twice as wide on the x and z axis.



The math is weird because halflings are actually kind of heavy to begin with, I think. Pretty sure human children are lighter than that, and fluff certainly makes many halflings out to be "well-rounded." Also *insert brief rant about how something 3' tall can't be as effective as halflings/gnomes can be*.
Actually at 3ft tall 35lbs would be a healthy weight for a human being. So Halflings aren't heavy.

[eggynack]

If you doubled in height, but remained the same width and thickness, then a rather strange, feature-distorting effect would occur, which I'm going to call the "Stretch Armstrong Effect." Not only would it be comical, but it would probably bear mentioning this in the spell.
Yes, it would be quite amusing. Seems like even more reason to arbitrarily go by an aggressively RAW based reading. I don't even necessarily think it's the only reading available, but it seems somewhat odd that the spell called out height with no attention paid to other dimensions.

[Baroknik]

Yes, it would be quite amusing. Seems like even more reason to arbitrarily go by an aggressively RAW based reading. I don't even necessarily think it's the only reading available, but it seems somewhat odd that the spell called out height with no attention paid to other dimensions.

I would think this would be to stop a doubling of lengths for creatures that are long and humanoid (though I can't think of any that aren't monstrous humanoids at best and the idea of WotC thinking ahead for one to exist is unbelievable).

EDIT: for example, if centaurs were Humanoids

[Gale]

I love science as much as it confuses me sometimes.
Thanks for the explanation though, guys. I kind of wish Enlarge Person didn't literally make your character twice as big but I suppose it makes more sense this way and is easier to calculate. My idea of making my small character character permanently large kind of seems odd now. Any creature who was literally twice as big would look out of place. I always assumed it was on a scale similar to humans of an identical height but I guess not. Oh well.

[Spore]

I love science as much as it confuses me sometimes.
Thanks for the explanation though, guys. I kind of wish Enlarge Person didn't literally make your character twice as big but I suppose it makes more sense this way and is easier to calculate. My idea of making my small character character permanently large kind of seems odd now. Any creature who was literally twice as big would look out of place. I always assumed it was on a scale similar to humans of an identical height but I guess not. Oh well.

Technically not. But I guess a lenient DM would let you fluff permanent spells. I would!

[nedz]

I suppose if Enlarge Person just doubled the space between your molecules then your mass (and therefore weight) would not change. This would increase your buoyancy though, and in the case of greater size increases could even make you lighter than air.:smallcool:

It doesn't though — it either makes you have 8 times as many molecules or makes the ones you have twice the size and therefore weigh eight times as much, or some such thing.

Pity really, I quite like the idea of a floating giant on the end of a piece of string; Why ? Because he's big.

[danzibr]

If it helps for perspective, my son is right about 3' and 30#. He's also just slightly... thick, let's say. I'd absolutely believe if he were 6' with his build, he'd be 180#.

EDIT: Derp, can't multiply by 8.

[MesiDoomstalker]

I'd like to point out why a Small Halfling Enlarged to Medium doesn't sync up with a naturally Medium Human is because of the Square Cube Law. But wait Mesi! Thats what everyone else was saying! It is, but I'm saying it in a different way. The thing is, a Halfling's anatomy is designed for its Small size. If you proportionately scaled upwards, you'd get an anatomy that had more mass relative to volume compared to naturally Medium creatures. Just like a Reduced Human would be lighter than a Halfling. Halfling's aren't just short humans, their anatomies are different, which changes the densities.

[Spore]

It also makes a difference if you are on the brim of being medium (there is not a huge difference between dwarves and halflings).

[Spuddles]

I suppose if Enlarge Person just doubled the space between your molecules then your mass (and therefore weight) would not change. This would increase your buoyancy though, and in the case of greater size increases could even make you lighter than air.:smallcool:

It doesn't though — it either makes you have 8 times as many molecules or makes the ones you have twice the size and therefore weigh eight times as much, or some such thing.

Pity really, I quite like the idea of a floating giant on the end of a piece of string; Why ? Because he's big.

What is the molecule you speak of? Is it related to Democritus' blather of atoms? Everyone knows matter is a mixture of elements of varying grades. A human contain air, for we can see it in his breath. He contains fire because he is warm, water for men are wetter than not, and earth of which we were sculpted.

tl;dr
Aristotle, bro

[Gnome Alone]

I assume it's because you become twice as tall, twice as wide and twice as thick. 2 X 2 X 2 = 8.

Thank you for the idiot-proof explanation, I had vageuely remembered this arcane square-cube law rigamarole but could nae understand nor 'splain it to save mine life.

[The Insanity]

Magic.

And math.

[Ravens_cry]

It also makes a difference if you are on the brim of being medium (there is not a huge difference between dwarves and halflings).

In 3.X default fluff, I would say there is quite vast differences.
http://img62.imageshack.us/img62/6594/xq2.gif 3.X halflings by default are more than a third shorter and far, far lither than dwarves.

[Greenish]

Mmn, the average height of a male halfling is 3'1'', while an average dwarf male is 4'2'' (and females are two inches shorter, in both cases). Average dwarf male weights 165 lb., though, compared to average male halfling's 35 lb.

So dwarf is, height-wise, really on the edge of small size, but weight-wise they're firmly in medium.

[nedz]

What is the molecule you speak of? Is it related to Democritus' blather of atoms? Everyone knows matter is a mixture of elements of varying grades. A human contain air, for we can see it in his breath. He contains fire because he is warm, water for men are wetter than not, and earth of which we were sculpted.

tl;dr
Aristotle, bro
Molecules are made from Catgirls.

[Drachasor]

Enlarge was originally going to be called "Biggie Size" but they got into a copywrite dispute and dropped it.

[MonochromeTiger]

Enlarge was originally going to be called "Biggie Size" but they got into a copywrite dispute and dropped it.

it doesn't actually make them heavier, just big boned.

[Gnome Alone]

Magic.

And math.

This could answer like 23.8% of the questions around here.