Can you interrupt the standard action a wizard acquired via celerity with a celerity of your own?

Question

The answers in the Question: A question about Celerity spells confused me...

Some people claim that immediate actions are resolved in the order they are called wich I agree, except in the case of celerity because it says you can interrupt with it:

The Celerity spell states:

(...)When you cast this spell, you can immediately take a standard action, as if you had readied an action. You can even interrupt another creature's turn when you cast this spell(...)

Immediate actions:

Immediate Actions Much like a swift action , an immediate action consumes a very small amount of time, but represents a larger expenditure of effort and energy than a free action . However, unlike a swift action, an immediate action can be performed at any time — even if it's not your turn. Casting feather fall is an immediate action, since the spell can be cast at any time. Using an immediate action on your turn is the same as using a swift action, and counts as your swift action for that turn. You cannot use another immediate action or a swift action until after your next turn if you have used an immediate action when it is not currently your turn (effectively, using an immediate action before your turn is equivalent to using your swift action for the coming turn). You also cannot use an immediate action if you are flat-footed .

So with this info let's say a fighter wants to attack you, you have to call your celerity before the attack roll right? If a wizard wants to cast a spell, you have to call your celerity before the spell benefits/roll etc. is called (to interrupt them of course), why can't you do the same while the wizard using celerity (let's say not on his turn), you could just interrupt his standard action (given by celerity) with celerity?

I'd like a RAW reference if possible (FAQ or pathfinder is acceptable if there's nothing in 3.X)

Answer 1

There's no practical guidance on immediate actions

So far as I'm aware, there's no developer commentary on the correct use of immediate actions. All readers have in both Dungeons & Dragons 3.5 and Pathfinder is the (extremely brief, almost telegraphic, borderline opaque) rules and players' interpretations of and opinions on those rules. In fact, to my knowledge there hasn't been a single written example—long or short—of how a normal combat round works on an action-by-action basis since Wizards of the Coast ended the Web column Game Stoppers in June 2002. (Earlier examples appear in Sword and Fist (Jan. 2001), too.) Seriously, at this point in either game's lifecycle, when a group agrees that the rules for immediate actions—and, in this case, also the rules for ready actions—work a certain way, that might as well be how they actually do work because, honestly, I doubt that true and practical guidance is forthcoming.

How this DM would resolve the question

Rather than using the normal rules for immediate actions—such as they are—from, like, the Rules Compendium (7, 124), the celerity spells (Player's Handbook II 105) grant the caster actions "as if [the caster] had readied an action." This means that the limits of the ready action apply, and that means if an action can't be interrupted—and other than spellcasting and movement, most can't—the caster takes the action granted by the celerity spell before the action that caused the caster to cast the celerity spell.

So, normally, the fighter's player would say, "I attack the wizard," while rolling a d20 and the fighter would, depending on the result, either hit and deal damage or miss and the caster would either have had to've taken the immediate action before the attack or take the immediate action now after the attack. By comparison, the celerity spells' ready action language makes it so those spells essentially grant the caster readied actions, making it so the caster can pick to cast them whenever an appropriate trigger presents itself. Typically, an appropriate trigger is When I'm attacked therefore allowing the caster to respond preemptively to an enemy's attack. (The game never addresses whether the enemy must actually take the action that triggered a ready action or if the creature can take a different action in light of changed battlefield conditions; fight that fight at your table.)

This also means that Namcigam could begin a fireball spell and Edudenacra could cast a celerity spell picking the trigger When Namcigam casts a spell and take the granted action in the midst of Namcigam casting the fireball spell. (Spells—unlike, for example, attacks—do have specific rules for being interrupted.) Namcigam could take an immediate action to cast a celerity spell, too, picking the trigger When Edudenacra casts a spell. This causes his fireball spell to fail, but Namcigam could then take the granted action from his celerity spell in the midst of Edudenacra casting his celerity spell! Namcigam would take his granted action first then gain the condition dazed and Edudenacra—if he still exists—could finish his spell then take his action granted by his celerity spell then also gain the condition dazed.

A word of caution on celerity spells

The power of the 4th-level Sor/Wiz spell celerity [trans] (PH2 105) shouldn't be underestimated. Although immunity to the condition dazed is difficult to acquire, even without it I've seen a high-level bard trivialize encounters against level-appropriate foes. Getting extra actions now is worth the high price. Doing so is just that powerful.

Answer 2

I would agree with the above comment.

This spell is quite powerful and it seems very possible to use it against itself.

However, unless you're using it as counter-spell (i.e. has a counteraction already prepared before the initial wizard start the spell) it's quite complicated to know that the opponent is actually using celerity and therefore, it is necessary to do a knowledge test (Arcana).