Sharing Concentration Spells with your Familiar.

[Craiconn]

If you are sharing a personal-effect, concentration-durationed spell with your familiar (say, Toothed Tentacle from LEoF), this creates *2* spell effects - one controlled by each of you.

Now say your Sorc/Wiz stops concentrating on the spell.  Does this cease the spell for both of you?  Or does the Familiar who is still concentrating on his "shared" version of the spell ... keep his version still up and running?

This article here didn't give me much of an answer.  Maybe I missed something?

http://www.wizards.com/default.asp?x=dnd/rg/20050913a

Familiar-Shared attack/offense spells seem like a strong optimization angle to purse.  Especially in regards to action economy.

[rot42]

I would rule that there is only one spell in effect here and that if the caster ceases concentration then it ends. The Share Spells ability is phrased that a shared spell can also affect a familiar rather than that the spell is actually twinned. I am not aware of any specific rules clarification, though.

[sirpercival]

Then you take Familiar Concentration and the familiar can maintain both.

[Craiconn]

Rot42 ... that's how I thought of it as well.  It would be different if the familiar actually "cast" the spell (via Imbue Familiar With Spell Ability spell).  RAW-wise though, it's really not clear.  Does anybody parse the RAW structure as being different than our intrepretation?

Sir Percival ... I was certainly excited about that feat until I took a look at the INT requirements of the Advanced Familiar.  You seriously need to give your Advanced Familiar some INT enhancement bonuses via spell or magic item.  Otherwise you are limited to usually 1st or 2nd level spells for him to use via that feat. 

In light of all that, I'm starting to think that potent Concentration spells (like Manyjaws, Telekinesis, Illusory Pit, Grasping Wall) are best suited to pass on to your Familiar via the Imbue Familiar With Spell Ability Spell (at high-middle or higher levels).  Again, to maximize the action economy.