Quote Originally Posted by Greywander View Post
I think you're missing the point. I have a giant that is twice the size of a human. How heavy is the giant? How big is the giant's weapon? How heavy is the giant's weapon? How much weight can the giant carry?

The point is, how do I answer those questions?

I wasn't starting off of the assumption that the Square-Cube Law applied to D&D or any other fantasy setting, I just wanted to explain what the issue was first before looking at some ways of handling things different and how those fail to capture all aspects of how very big things are often portrayed in fiction. The reason I bring up the example of the cubes again and again is because it's such a basic, elementary demonstration that something twice as big should be 8 times as heavy, no matter what physics your universe is running on.

If we want strength and weight to scale at the same rate, then we could just make a giant twice the size of a human be 8 times as strong, but then I feel like strength ramps up way too fast. It seems like we'd want to instead make the weight scale up more slowly, but I don't know how you'd do that in a way that makes sense, given the cube example.

I dunno, maybe I should just accept that a giant's greatsword would have the same proportions as a shortsword. That just looks weird, though. I guess the crux of the issue is that one part of my brain thinks the giant should have identical physics to the human, while the other part of my brain can't ignore the cube example and that the physics must necessarily be very different. And I guess I'm trying to find a way to reconcile these, a way for the giant to have the same physics as a human without violating the example given by the cubes.
I mean, I think the answer that makes sense is that the giant is in fact 8 times as strong, when strength is expressed in terms of bulk modulus and yield modulus. That doesn't mean that the giant's strength score is 8 times higher, nor that the damage it deals with a strike is 8 times higher. For one thing, 'damage' need not have any sort of linear relationship with e.g. pressure or force exerted. In something like D&D where damage is linear in Strength score but carrying capacity is exponential, this is certainly the case - and that logarithmic relationship is extremely forgiving of whatever scaling law you want to have Strength obey. Or, it might just mean that more of the giant's strength is in the static properties of their body rather than in the balance of tensions between muscles. Which supports the 'big, strong, and slow' sort of fiction (whereas for real things that size, the 'slow' impression is usually more about distance than large things actually being slower - large things in reality tend to be faster by the numbers).

There are a bunch of other weird things you could do. For example, you could decide that the magic in dragons, giants, etc acts to weaken gravity on and around it linearly with size. So the giant is only 4 times as strong as a human but experiences 1/2 the gravitational acceleration, so it doesn't need anything funky for its body to not collapse. Also meaning that the giant can lift a proportional 2-handed sword, but it won't be swinging it proportionally as quickly as a human would swing a 2-hander because its magic is lightening the sword but not reducing its inertial mass. Also this would have a convenient bit of fiction where aerial hijinks actually become easier around dragons and giants - you can jump up the side of a giant if you judge the extent of its field correctly, in a way fundamentally unlike how you'd e.g. try to jump up the wall of a castle.

Or you could say that the magic empowering the giant or dragon means that the rate of passage of time is literally different within its body. Mass scales as density * L^3, pressure is density * L^2/T^2. So when you double L, mass goes by 8 but pressure goes by 4, which is the problem. Unless you also simultaneously scale T by 1/sqrt(2), in which case they go in proportion. So essentially, in the time the normal human's body experiences 1 second of time the giant's body has only experienced 0.7 seconds. In practice this probably would correspond to strength scaling as the cube of size rather than the square, but depending on what happens when momentum fluxes cross that boundary of different rates of time passage will determine what specific sorts of feats of strength you'd be seeing. One reading of it could be something like 'the giant is only in phase with reality for 7/10 of every second' such that the ability to stop a giant in motion has the full 8x difficulty, but the ability of a giant to actually accelerate its own body would only be 4x. So while in principle the giant could deliver 8x on external objects due to Newton, because its ability to accelerate external objects is contingent on it also accelerating itself, the difficulty of moving its own body always bottlenecks that.

Anyhow, you have lots of options. The deeper question is, are any of these options enabling other interesting things if you explore them and their knock-on consequences?