Infiniti2000 said:
Sure. Why can't it work on the spell slot, though, not the spell? You lose a spell slot, then you regain it. Casters who prepared spells are somewhat screwed while those who don't are not. I might even consider allowing the slot as an open slot for preparation casters because the spell wasn't actually cast and it was "rested for".
But the question becomes, why would a DM rule that it is similar to casting the spell (or not preparing the spell) when even Death itself does not necessarily lose prepared spells?
That appears to be a dicotomy which the "you just gain them back like you gain all other ability related attributes" does not have.
Infiniti2000 said:
It can create a problem. Consider a caster with 3 slots of his highest level spell still in memory. (For this example, they need to be prepared.) His stat drops and technically he's only allowed 2, but he doesn't use the spells and keeps them. The next day while preparing, what can he prepare at his highest level spell slots? Can he change at one spell? Two? All three? If he tries to change out one, does it suddenly go poof?
That's a really tricky scenario that is easily avoided using (e.g.) Frank's rule or even the one I offer above (turned into open slots upon regaining the ability score).
Like you said to me, this is a strawman.
If you still have the prepared spell but just do not have access to it, that means that you cannot modify it.
So, if the caster has two spell slots available, he can do whatever he wants with those two slots just like always. The third slot with the prepared spell still in it is unavailable.
No problem at all.
And, this follows RAW closer. If you do not cast a spell, you do not lose the preparation of it. In this case, you would just lose access to it.
Either interpretation is fine, it's just that my proposed interpretation is closer to RAW in that spell preparation is only truly lost if the character casts the spell (or dies). Not if some condition just temporarily prevents him from accessing the spell.
Plus, I do not know of a rule that takes away spells (outside of casting or death). But, there is a rule that ability score changes result in attributes changing accordingly. Your interpretation (somewhat arbitrarily) states that this rule applies for everything except spells (or spell slots).