mflayermonk
First Post
That is talking about using that as a method for thinking about challenge rating.
It says nothing about actually messing with monster's stats.
If you buff the hit points that way, then it takes just as long as it did before to kill with mundane weapons (because the effect is the same), but it now takes much longer than it did before with HP damage spells or magic weapons (because the HPs are now so much more).
So, the effect is you just turned a thing that was easier to kill with magic into one that's harder to kill with magic.
I see. Damage resistance b/p/s is worse than just having the normal hit points for the monster in campaigns with a lot of magic items.