Majoru Oakheart
Adventurer
This is the key portion, but what I get out of it is that the rules are complicated in that there are a lot of "fringe" rules that people forget to apply when advancing a monster, applying a template, adding a class or PrC, or just running the creature.WotC_GregB said:“Gotcha” rules are usually modifiers (often related to size class and the like) that are almost invariably forgotten or miscalculated. As we come to the end of 3rd edition, the sheer number of Gotchas out there is daunting.
Did you remember when the monster increased in size that it now gets pluses to disarming for its weapon being larger, pluses to grapple as a size modifier, that it's ac goes down due to size, that it gets bonuses against certain types of creatures due to levels in Occult Slayer, pluses to hit orcs and goblins due to it being a dwarf, pluses against spells due to being a dwarf, did you increase the damage on his weapon due to size correctly, did you remember you apply the Dodge feat this turn, etc?
These, I believe, are what they refer to as "gotcha" rules. They tend to be rules that are used only in specific circumstances, so you need to remember the circumstances in which to apply them. Since you don't use them all the time and there are just SO many of them, people forget them.
So, what he's saying about 4th ed is that he likes it because there is some science behind the creation of creatures but enough wiggle room to just change things how you want them to be changed without having a bunch of "Gotcha" rules that you may have forgotten.
I interpret it to mean that you can create a creature who is Colossal who has X pluses to hit and x damage and x saving throws without having to worry if you did all the size modifiers correctly. You are given the freedom to make what you want without remembering a bunch of rules to do it. And no one can tell you you made a mistake, since there's no way for someone to sit down and say "This is EXACTLY what bonuses this creature is supposed to have".