The Value of Defense vs. the Value of HP

I have often found myself asking, "What's the point of damage resistance if you can just get more HP"? Well, besides the issue of diminishing returns, defense and HP have some intrinsic advantages.

First of all, a high enough defense rating can make small attacks do 0 damage. A tank has a superb defense rating: bullets just bounce off it. After some point, a weapon does no more damage by hitting 50 times than it does once. HP can be crippled by automatic weaponry, on the other hand.

However, also look at some basic math here. Let's create a little scenario: one person with 9999 HP and 10% DR, the other with 999 HP and 90% DR. Now, remember that even if Guy #1 had no DR, he could still take 9 HP more damage! Now, both get hit by an attack inflicting 1000 damage before defense. Guy #1 takes 900 damage. Guy #2 takes 100 damage. So far, it looks even. Ah, but then Guy #2 casts White Wind. When he heals himself 899 damage, he heals the damage he took almost 9 times over! But Guy #1 isn't even fully cured (still has a deficit of 1 HP!) To summarize: defense is preferable when curing heals predictable damage.

But the flip side of the coin goes firmly in HP's direction. In the same case, a simple Blowfish spell would instantly kill Guy #2 and merely irritate Guy #1. Attacks inflicting predictable damage slaughters defense.

Also, it would seem that when damage is proportional, defense gets a major advantage. Suppose someone had 4 HP but nearly invulnerable defense. Another person has 100,000 HP and no defense. If both get hit by Demi, the first guy has an easier time of healing and is probably better off. The guy with 25,000 HP remaining has been majorly weakened; not so much the defense guy. Do remember, though, that Guy #3 would get slaughtered by an attack that ignores defense or reduces defense. And the flip side of the Demi coin is that Demi can whittle down a defensive person if nothing else works.