Move for Larger Creatures

[lwcamp]

Originally Posted by Kuu

When designing larger monsters, does Move increase with size, a fraction of size, or as a square root of size?

Or should it be modeled as Enhanced Move, since a larger creature has more trouble turning around? If so, what is the ratio of Enhanced Move to size?


The reason I'm asking this is because I notice that, in many movies and fictional stories, larger creatures are much more clumsier and slower than smaller ones. This probably has to do with the square-cube law and encumberance, but I don't know the extent to which it affects a large creature.

For example, how fast would a 40-yard worm-like creature (with ST 200, BL 8000, and weight 500 tons, that, if 2 yards long, would have Move 1) be able to move?

EDIT: Looking through Space p151, it seems that a more accurate weight would be 800 tons, as well as a ST of 233 and a BL of 5.43 tons.
EDIT 2: Going by the square-cube law, it seems that something that big would be crushed under its weight. So much for that example.

Going from data of extant animals, you tend to find an optimum size for fast movement, which decreases as you get larger or smaller. However, this is a fairly broad maximum. For running, the maximum is somewhere around 10 kg to 200 kg - both really big and small animals seem to drop off in speed (but not all that fast. Note that racehorses tend to be bigger than the optimum because they have to carry the extra weight of a rider). For slithering, the maximum size is probably considerably smaller. The fastest slitherers are likely the mambas, coachwhips, and racers, all of which have a GURPS move of perhaps as high as 3. The largest slitherers - the green anaconda and the reticulated python, along with other giant pythons, have a GURPS move of 1 (or less).

Luke