|1 person marked this as a favorite.|
The biggest problem, I found, was that some things just made no sense at that size. Even if a 500-foot-long beetle notices the damage you do to it, do feats like Stunning Strike make any sense?
The reality is that creatures above Colossal really need an extension of the size rules. I was kinda hoping it would be there in the Mythic stuff, but I suspect it was just too squirrelly of an issue. Under 3.5e, there was a book called the Immortals Handbook Epic Bestiary Volume One (there never was a volume two) that had a decent section on expanded sizes, but it didn't really address some of the core issues.
Maybe sometime there will be Ultimate Monsters, with some optional rules on expanded size. For now, I'd recommend staying away from creatures above Colossal except as plot devices :)
Personally, I always wanted to see some rules for diminished effects beyond certain size differences - for example, damage is by medium creatures is halved for every size category above Colossal, so when Big Mac the All-Beef Barbarian hacks at King Mogaru, his damage is quartered even before DR or any other modifiers, and Big Mac's ally Small Fry the Halfling Rogue is in even worse shape, doing 1/8 the damage because he's Small instead of Medium.
I never actually fleshed any of that out; truly ginormous creatures were tough enough as it was, but some end results and corner conditions of the rules (flanking? 5-foot steps?) ended up sort of silly.