Deity (or similar) based features

[Lord.Sorasen]

My specific case: In the campaign I am currently running, one of my players is playing a paladin, and asked about the Mystic Fire Knight. Now, that little set of alternate class features requires one worship the god Mystra, but that sect doesn't exist within my campaign world, so I allowed her to have such powers regardless, as a worshiper of Pelor. What I'm wondering is whether allowing this paladin to take feats/alternate class features/what have you which, due to deity requirements, would not be legal normally, might break the game? My first thought is "of course not, she is a paladin playing in a game with a druid (nonwildshaping but still), a psychic warrior, a cleric, a beguiler, and a dragonfire Adept. Should be fine! But I am partly worried that there's something I don't see.

General case: I don't see why this wouldn't apply to every class, really. Were the deity required entries made for balance reasons, and would it be a problem to get rid of them as a whole? What about racial or regional requirements?

[tyckspoon]

Deity requirements are almost always built around world-fluff, not balance ideas (the only thing I can think of where it might be relevant is clerics, where if you had a really well-scripted set of deities you might be able to do some balancing with careful assignment of domains/domain powers as pre-reqs. It should go without saying that there is basically no pre-existing set of deities that can really do this.) In the case of Mystic Fire Knight and most of its brother features/PrCs, they want Mystra because they were written for the Forgotten Realms, which is a setting where the gods have very distinct areas of control and are somewhat territorial about them. So, for the Realms, it makes sense for the world that if you are going to have a sect of Paladins that have extra magic power, they're going to be the ones in service to the Goddess of Magic.

If you want to ditch those requirements or rewrite them to be more suitable to the world you play in, feel free. You won't hurt any balance by doing so (or, more accurately, making them available at all already causes their balance concerns, regardless of which gods make them possible.)

[Greenish]

Deity stuff is mostly fluff, even WotC doesn't consider it a huge limiting point. Case in point: RKV is as written specific for Wee Jas. The sample RKV worships St. Cuthbert.

Though Mystra does have some cheese to her name, but usually if you'd allow something for a follower of certain god, it's not going to get any more broken in the hands of a follower of another.

[Lord.Sorasen]

Deity stuff is mostly fluff, even WotC doesn't consider it a huge limiting point. Case in point: RKV is as written specific for Wee Jas. The sample RKV worships St. Cuthbert.

Though Mystra does have some cheese to her name, but usually if you'd allow something for a follower of certain god, it's not going to get any more broken in the hands of a follower of another.

Well, I'm talking about more than that, though. I'm specifically referring to stacking the alternate class features of different God-req classes. I figured it wouldn't matter much because Paladin is paladin, but I wanted to make sure it wouldn't be totally game breaking. No one else is interested in doing this in the party other than the paladin for paladin class features, if that helps.