Size Damage Reduction
Instead of proportionately scaling Wound Points, I came up with the concept of Size Damage Reduction (SDR), which essentially states that:
(a) when a creature is very big, it can ignore attacks of a certain "size" (i.e., a certain hit point value)
(b) when a creature is very small, it may be harmed by attacks that are very small (in essence, a fraction of a hit point of damage; rated in negative hit points worth of damage)
and it implies that
(c) +2 = x2. That is, a 2-point increase in damage is essentially double damage. This is sort of implied in the existing Strength-Lift chart where ~+4 Strength (=+2 strength bonus) translates into x2 carrying capacity.
Therefore, a Gargantuan creature might have an SDR of 12/*, meaning that no attack of any sort that does less than 12 points of damage will have any effect whatsoever. An attack that inflicts over 12 points is reduced by the SDR of 12 (e.g., a 10d6 fireball for 35 points is reduced to 23 damage).
You cannot therefore kill this creature with a barrage of magic missiles. Trying to do so is like trying to kill a man by throwing ping pong balls at him.
With the concept of SDR in place, we don't have to have massive numbers of hit points, and we maintain a semblance of realism.
There are other suggested rules, such as Size as Cover (very big creatures may partially or wholly ignore area effect attacks simply because they are not wholly in the area of effect).
For my full house rules, see
www.freewebs.com/d20elements
