Thought I'd toss an idea in there...
If you use something like the draft-feat that Paladin wrote (above) how about it not being an exactly equal spell.
Maybe caster level of the new spell is reduced (by 1, or 2 or some other number). (so a 9 level cleric casting fireball would be doing 8d6 damage rather than 9d6 as a sorcerer would - and adjustment to any other caster level dependant effects like range)
-or-
the spell uses a spell slot one level higher than what it would otherwise (i.e. a wizard taking cure light wounds would have to use a second level spell slot for it).
I think either of those would keep the caster from stealing the spot light off the other caster-types that would normally be able to cast said spell.
Anyway, just some rambling/random thoughts to add to the fires...
If you use something like the draft-feat that Paladin wrote (above) how about it not being an exactly equal spell.
Maybe caster level of the new spell is reduced (by 1, or 2 or some other number). (so a 9 level cleric casting fireball would be doing 8d6 damage rather than 9d6 as a sorcerer would - and adjustment to any other caster level dependant effects like range)
-or-
the spell uses a spell slot one level higher than what it would otherwise (i.e. a wizard taking cure light wounds would have to use a second level spell slot for it).
I think either of those would keep the caster from stealing the spot light off the other caster-types that would normally be able to cast said spell.
Anyway, just some rambling/random thoughts to add to the fires...