Can a divine caster spontaneously cast from an "open" spell slot?

[Nuun]

For example, a druid prepares some spells in the morning but leaves a 1st level slot open. Can she use that open slot in the middle of a fight to cast Summon Nature's Ally? Or must she spend 15 minutes to prepare some random 1st level spell first?

The language of the spontaneous casting section suggests the latter, but the spirit is more in line with the former. Help?
Thanks,
-nuun

[Some Random Dood]

The text does sound like you have to give up a prepared spell. But, I don't see why you couldn't use the open slot for it.

[Adamantine Dragon]

I looked at this the other day for my druid and concluded that the wording of the RAW is that if you leave a slot open, you can't spontaneously cast since you aren't replacing a spell.

PRB wrote:

She can “lose” a prepared spell in order to cast any summon nature’s ally spell of the same level or lower.

It's up to your GM though.

[Jeraa]

Nuun wrote:

For example, a druid prepares some spells in the morning but leaves a 1st level slot open. Can she use that open slot in the middle of a fight to cast Summon Nature's Ally?

No, she can't. You have to use a prepared spell to power a spontaneous Summon Nature's Ally (or a cure spell, if a cleric).

Quote:

She can “lose” a prepared spell in order to cast any summon nature's ally spell of the same level or lower.

It specifies a prepared spell, not an unused spell slot.

Nuun wrote:

Or must she spend 15 minutes to prepare some random 1st level spell first?

Yes, you would have to prepare some spell in that slot to use it to spontaneously cast a Summon Nature's Ally (or cure, if cleric) spell.