[RPG] Can you cast an immediate action spell while you are casting a one round spell.


This came up on the /r/pathfinder_rpg subreddit, and it made me wonder, is it possible to cast an immediate action spell while you're casting a one round spell?

The idea was that someone could begin casting Summon Monster on their turn, get attacked, and cast Emergency Force Sphere as an immediate action to block the attack and continue casting Summon Monster.

To me, this seems wrong, as you would have to break your focus on casting the Summon Monster spell to focus on casting Emergency Force Sphere, and to my knowledge, if you willingly drop concentration on a spell being cast, it's the same as failing a concentration check, and the spell is lost.

The person in question seemed to be convinced because the spell's description didn't state you couldn't use it in this way, it had to be viable. (Even though Pathfinder is clearly a Rules-Can, not a Rules-Can't game).

I wanted to reach out to you guys and see if you have any information one way or the other.

Best Answer

Working from the rules listed here it seems as though no.

I'll run through my train of thought on this.

As listed in Casting time:

  • A spell that takes 1 round to cast is a full-round action. It comes into effect just before the beginning of your turn in the round after you began casting the spell. You then act normally after the spell is completed.
  • When you begin a spell that takes 1 round or longer to cast, you must continue the concentration from the current round to ... the next round (at least). If you lose concentration before the casting is complete, you lose the spell.

And from the Concentration subheading under Duration:

  • You can't cast a spell while concentrating on another one. Some spells last for a short time after you cease concentrating.

Because Summon Monster has a casting time of 1 round, it seems to me that you would have to interrupt concentration in order to cast force sphere, and thus lose the casting of Summon Monster.