Spells with a duration of Concentration mean you loose your standard action to maintain the spell. Higher level spells often add extra rounds after you stop concentrating, making them better.
I want to make a magic item that lets me extend concentration of spells. I want your help to define, price, and come up with a reasonable crafting requirements.
To start this discussion, I present the Phantasmal Gem from the ARG.
Aura faint illusion; CL 3rd; Slot none; Price 4,000 gp; Weight 1 lb.
DESCRIPTION
This small cut crystal appears to be filled with hazy, indistinct images that constantly shift and vary. If a spellcaster holding the phantasmal gem casts an illusion spell with a duration of concentration (or concentration + a number of rounds), the illusion lasts up to an additional 10 rounds after the spellcaster ceases concentrating on it. The spellcaster may end the illusion early as a swift action. The phantasmal gem can be used multiple times in a day, but cannot grant more than a total of 10 additional rounds of illusion spells per day. A gnome using a phantasmal gem can recharge it by expending uses of spell-like abilities gained through the gnome magic racial trait. Each spell-like ability expended as a standard action recharges 1 round of duration to the phantasmal gem (up to a maximum of 10 rounds).
CONSTRUCTION REQUIREMENTS
Craft Wondrous Item, creator must be a gnome or a wizard specialized in the school of illusion; Cost 2,000 gp
The spell I am currently interested in is Raging Rubble a transmutation spell with a duration of concentration + 2 rounds.
My initial stab would be to start with the gem, and swap illusion with transmutation, remove the gnome choice, and call it done.
Anyone have any comments, suggestions, or alternate ideas?
/cevah
I'm assuming you're going to create this and submit it to your GM as a homebrew item? If so, this may help.
In psionics, you can get a 3rd lvl Power called Solicit Psicrystal, which allows your Psicrystal to take over the concentration of a Power for the Psion for 1 round/level, thus freeing the Psion to do other things.
You could just create a 3rd lvl spell that does the exact same thing. You'd need to create some magic gem or item that is comparable in cost as a Psicrystal as well. A psicrystal is gained through a feat (with no gp cost), and it acts as a familiar. What if you used Improved Familiar feat to do this?
If you're completely sold on going the Phantasmal Gem route, you could change the item around to do exactly that same thing except for transmutation spells, but I would say it has to be a Crafted Wondrous Item from a Transmutation specialist, and it would be 4000gp x 1.5 (6,000gp) to buy, or 3,000gp in raw materials to create plus the Wizard's fee.
When I said swap, I meant the speciallist also. :-)
What is the 1.5 multiplier for?
/cevab
That’s my rule for players homebrewing items that don’t exist. I was throwing it out there as a suggestion you could pitch to your GM.