View Full Version : On how to decide the Size of creatures in D20

2009-08-06, 12:01 PM
When creating D20 creatures, or statting out approximations of real-world ones using the D20 rules, what's the best way of ensuring a creature is not undersized or oversized, for the size given?

I figured that, as a rule, the Wizards weights and lengths were good for most, but for some, there is leeway.

For example, I figure a flying creature can get away with being much lighter than its size would indicate.

On deciding whether creature should be in one of other, if close to the cusp, I think comparing it next to a mid-range creature in each size (equivalent to a six ft tall human, for Medium) is a good guideline. With weight reduced as appropriate- a 2 ton Large creature, or 16 ton Huge creature, is equivalent to a 500 pound Medium creature, for example.

For example- T-rex- Gargantuan or Huge?

(18 ft tall, 13 ft tall at the hip, 40-44 ft long, between 6 and 7.5 tons)

Comparing it to a Huge humanoid- 24 feet tall (equivalent to a 6 ft human).

Scaling them both down to Medium, it would be 4.5 ft tall, 3.2 ft tall at the hips, between 10 and 11 ft long, and between 187.5 and 234.375 pounds in weight.
(scaling 32000 pounds to 500 pounds)

This seems comparable to a lizardman.

Comparing it to a Gargantuan humanoid- 48 ft tall.

Scaled down to Medium, it would be 2.25 ft tall, 1.6 ft tall at the hips, between 5 and 5.5 ft long, and between 24 and 30 pounds in weight.
(scaling 250000 pounds to 500 pounds)

This seems comparable to a fairly small dog.

Conclusion- T-Rex should be Huge.

Does this seem like an OK approximation?

2009-08-06, 12:10 PM
I go just by body height: Under 4 feet is small, over 8 feet is large, over 16 feet is huge, and so on. For quadrupeds I'd take approximately 2/3 of that for shoulder height.
And that's it.

2009-08-06, 12:13 PM
What about Long Bipeds (ones longer from nose to base of tail than they are tall) or ones with heavy tails? standard quadruped and biped rules work, but some creatures are mid-way between the two.