The spell reads as follows.
Produce Flame
School evocation [fire]; Level druid 1
Quick Reference
A torch sheds normal light in a 20-foot radius and increases the light level by one step for an additional 20 feet beyond that area (darkness becomes dim light and dim light becomes normal light). A torch does not increase the light level in normal light or bright light.
Casting Time 1 standard action
Components V, S
Range 0 ft.
Effect flame in your palm
Duration 1 min./level (D)
Saving Throw none; Spell Resistance yes
Flames as bright as a torch (see Quick Reference at right) appear in your open hand. The flames harm neither you nor your equipment.
In addition to providing illumination, the flames can be hurled or used to touch enemies. You can strike an opponent with a melee touch attack, dealing fire damage equal to 1d6 + 1 point per caster level (maximum +5). Alternatively, you can hurl the flames up to 120 feet as a thrown weapon. When doing so, you attack with a ranged touch attack (with no range penalty) and deal the same damage as with the melee attack. No sooner do you hurl the flames than a new set appears in your hand. Each attack you make reduces the remaining duration by 1 minute. If an attack reduces the remaining duration to 0 minutes or less, the spell ends after the attack resolves.
This spell does not function underwater.
My question is that with a high level druid with durations of 10+minutes, can other spells be cast while this spell is maintained as with call lightning?
There are rules for "Holding the Charge" in the Magic chapter under "Duration". But those rules don't seem to apply here. Mostly because they refer to "Touch" spells. Produce Flame is a "Ranged Touch" spell which is different.
To my knowledge there is no general rule for this situation, so the Specific-Trumps-General axiom comes into play. Only, in this case, there is no specific rule for it either.
Well, that's the dog's bleedin' breakfast there eh? What to do, what to do? Well, we could apply some logic here and make a judgment call.
Occam's Razor. Which is more likely?
1. The intent of the spell is to create a multi-purpose utility/combat spell that shed's light and can be used to harm the caster's enemies.
2. The intent of this spell is to cripple a spellcaster to the point that he will become nearly useless for the duration of the spell, relegating him to little more than a NPC torch-bearer who can occasionally fling his torch to do less damge than a good crossbow bolt.
Me, I support option 1. The druid can still make himself useful while this spell is active.
Side note: the spell references "open hand" which seems to say that this hand must remain open. Spells with somatic components usually require complex hand gestures that might be impossible to do with an open hand. Which means I would interpret this that the druid must use his other hand (spells usually only require one free hand) or, if he cannot or will not free his other hand for spellcasting, then he would be unable to cast spells with somatic components unless he discharges his ongoing flame first. But that's just me.
I would agree, but I would also add that I don't think that the flame would interfere with most other activities.
I do kinda wonder, tho, if the intent of the spell is to reduce the duration by one minute for regular touch attacks as well as ranged touch attacks. The way it is written, it certainly does, but since a ranged touch attack is generally considered a better attack for a spell caster than a regular touch attack (since he or she doesn't have to enter melee), I can't help but wonder if the intent was allow touch attacks for the normal duration, only reduced for throwing the flame.
As I said, the wording would seem to indicate otherwise. But I do wonder.