Good, lawful al. shift from actions to balance chaotic, evil

[Stonebar]

Because the dark side is more seductive, so says Yoda; this is why wizards are effected Joke aside I think alignment shifting anything is a bad idea, for mechanical reasons.

[Ariella]

I am a fan of chance alignment shifts from spells good/evil/chaotic and law, Also a fan of evil and good cleric spells not working at all if cast by a cleric of the opposing alignment. While DM's handing out shifts is the ideal solution it is also the impractical one, The rules of PnP where designed around a different game. Four people sitting around telling every action they do casting or other wise to the DM or at least in-front of them, We don't and can't have the same system and so automating a part of it eases the work load of the DM team.

That said i would not have it as a point per cast it would be a 5% chance or less each time you cast the spell to earn the slight shift. Something that would take thousands of casts to shift or abuse. Not that there is much to abuse as BG already has a custom system to stop clerics casting, paladin ability's from working and so forth.