Item creation: The Mystic volunteer

I am a bit on a roll about lab stuff:

I find it odd to visualise specialisation in spells that you can't practice, as well as creating them and having a perfect result without having a target first. This could of course be remedied by getting a volunteer of the correct type, but those are not always easy to come by.

I visualise a target/puppet that uses Vis of the appropriate form to provide a target to practice on (for instance to create a Demon's Eternal Oblivion, you'd use Vim vis, infernally tainted if you have it), with a +1 to the lab total per Vis used. The Vis is used through the season, and nothing of it remains at the end of it.
The LT bonus could be used to invent spells, or as an advancement bonus to mastery or penetration.

To me, the general idea seems balanced and interesting, however, I have no idea how to pour this into Ars Magica rules. I'd say some Rego Vim would be appropriate, with a total effect about 40 (which would be a +2 GQ, you can get higher, but it'll cost you).

You mean like researching a dragon affecting spell when you don't have a dragon handy?

I have always assumed that Hermetic Magic Theory is sufficiently precise and comprehensive that you could accurately extrapolate from the smallest samples of the appropriate form.
And that you might get a study bonus if you did have a sample of the target to experiment upon (eg a baby dragon in the lab).

Yeah, I've always seen Hermetic Magic as being a bit like an academic discipline. Sure, there are experimental aspects, but it is also possible to perform theoretical calculations and extrapolations. And there are also probably some principles like "Forms", "scale-up", and "simulation" involved. So, having a "fire", and a "small" "lizard", and maybe a "book about dragons" on hand somehow helps you to think about magic to affect a dragon = "large fire breathing lizard".

By comparison, take a relatively practical modern academic discipline like Civil Engineering. A Civil Engineer can happily design a bridge before building it and without needing all the materials actually on hand --- using a combination of simultations, tests on samples, models, structural data from books, etc.

So, if I'm understanding correctly, you're theorizing that, by expending a pawn of the appropriate vis during the spell invention process, that would add +1 to your lab total for that season?

I'm having a hard time seeing that, especially as how using a pawn of vis in spell casting adds +2 to your CT. If you're going to house-rule using vis in spell creation, I would think it would have to be at least as effective as vis in spell casting.

I can't put my finger on it, and I've been thinking about it for a while, but this seems...wrong. The idea of adding vis to increase LT seems fraught with risk for the researcher and possibly exploitation by the player.

Is it really that difficult to create a lab specialized for inventing spells?

The very opposite. Suddenly Vis-rich covenants actually have the major advantage they should have.
I´ve used it for a looong time. But i also require everything with a labtotal to use some Vis ( and if you dont have any, you get halved labtotal instead ).

I think that is the point of the idea...

This sounds like a description of a Supernatural Lab Virtue. It's an item that gives a bonus to a particular activity.

Once the troupe's agreed what it does, (and the magus has made it) just follow the rules in Covenants for how to install the Virtue into the lab (and rules on how many such things can fit in a lab, etc).

It seems I was mistaking about the feel and balance of it, I'll propose it as a supernatural virtue, though I have no idea how to get it in my lab as of yet.