I am just trying to figure out what good a cleric's (or a paladin's) aura is. It seems like all it does is give off an alignment for identification purposes. Also, are there any other classes that give an alignment aura?
If a character gains the saint template (BoED), they get an aura like the nimbus of light feat (BoED). The nimbus of light auras provides for some level of protection from undead but an aura without that is prolly only good for free chow and a place to sleep at the local temple.
It may be fluff, but in the Paladin description, it says that two palladins, regardless of church, country, race, or even plane of origin, will always recognize each other as paladins. In my games, the aura is part of that.
Here's some other "in my game" stuff relating to the auras.
Should someone try to hide their aura, they can try to do so. They make a disguse check with a penalty equal to their level. Anyone who would be "sensitive" to such an aura (evil cleric vrs good cleric) gets a wisdom check to oppose and notice that so-and-so reeks of good.
Non-detection type spells supress the aura, if it is within the intent of the spell to do so.
Paladins can recognize each other, always, even if the aura is supressed. Ex-paladin blackguards (but not other blackguards) get to make the opposed check, even if the Paladin's aura is concealed. However, if the aura is concealed, the blackguard takes a -5 penalty.
It may be fluff, but in the Paladin description, it says that two palladins, regardless of church, country, race, or even plane of origin, will always recognize each other as paladins.
Uh...that's not actually what it says. It says they will recognize in each other an eternal bond that transcends background. That doesn't in any way suggest they recognize each other as paladins.
I don't have any problem with your house rules, but these kinds of reading comprehension errors are a pet peeve of mine. :)
There are always interesting ways to work these rules into a game. There is a cleric in my game, Lawful Good, who worships Helm, LN, which means that no matter how "good" he is, because he venerates Helm, he radiates Law and law only.
Traps that detect alignment will pick up the deity's alignment, as will NPCs that detect the cleric. This can make for some interesting RP hooks.
Basically, some creature that eats good, with detect good active, will notice that the party cleric is awfully tasty looking. It's mostly for flavour purposes.
The cleric aura mentioned in the Players Handbook says to see the spell "Detect Evil". I pretty much just change the spells area of effect from CONE to AURA. Since no duration is mentioned I can assume that it's a constant and ongoing effect. Just leave everything else as is. As to what good it is, there are a number of instances I can see it being useful. Lastai's Caress a spell from the Book of Exalted Deeds (p.102), only works if you KNOW the target is evil. Taking a moment to study a suspicious character could determine if they are evil or just look shady. Finally, if you take the aura business to it's maximum extent, you can further determine if the target of inspection is in opposition to you in the matter of LAW/CHAOS. So you can actually have 2 auras going at once, you merely have to concentrate on someone in aura range to gather a bunch of useful information.