Couldn't find this answered elsewhere, so here goes:
What are the requirements for someone to be a lab assistant? Is a score in magic theory enough?
What about setting up or improving a lab? Does that require the Gift, or is a mundane with a magic theory score of 3+ perfectly capable?
I'm having visions of a wizard's lab looking something like the opening scene of the movie Hudson Hawk - lots of mundane assistants scurrying around while the wizard stands on a podium somewhere directing and personally doing only the really important put-strange-crystal-in-magical-machine bits.
Lab assistants: Having the Gift is sufficient but not necessary. Having an attachment to the Gift (a familiar, some Failed Apprentices, a faerie via Becoming) can also do. It seems like having had the Gift and being magically attached to one who does are sufficient. I don't think there's a clear-cut rule.
Setting up/improving labs: You need to have Magic Theory 3 to set up a lab and improve it. This can shift to 3+Refinement. I don't recall the need for the Gift. You do want to be careful about Refinement, though. You could fine yourself with a lab you don't know how to use. Of course, it only takes one season to remedy this, so if you don't need your lab for a while you could save some time letting someone else refine it.
Usually you need to have The Gift, this is described in the core rulebook. Having a Score in Magic Theory merely makes you a better Lab Assistant.
There are some special circumstances where characters who don't necessarily have The Gift can assist in the Laboratory. The most common such circumstance is a familiar, this is described in the core rulebook too. There are a few other special cases described in some of the supplements.
I'd say primarily the assistant needs the Gift. I'd also say the assistant needs to have his Arts opened, so his Gift becomes 'activated'. This would give him a score of 0 in Magic Theory, so by way of connection, Magic Theory is required. Having a core above 0 just raises the bonus the assistant gives.
Such an assistant with no art scores, like a failed apprentice or a first year apprentice, can do a few things themselves, requiring no Lab Totals. Like fixing Arcane Connections or stuffing vis in devices. Of course, this requires a score above 0, because of the limit of vis used per season. MT of 3 lets the assistant set up his own lab, and above that lets him improve a lab.
In all my years of playing ArM we've only used assistance from apprentices. Even though my current two sagas both feature failed apprentices working as teachers and doing odd jobs at the covenants.
Perhaps for your "vision" you could consider the Minor Outfitting Virtue: Slaves, or Servant, located in Covenants in pgs. 115-116. Sadly you would need the optional rules to see the effects in the lab, but for roleplaying purposes is valid to have that vision in a lab of enough size, of course. Having a lot of servants ("slaves") improves the upkeep a little and gives a good bonus to Mentem and Corpus activities, but offers a little less of safety and aesthetics to your lab. They, of course, don´t need to have the Gift, neither Magic Theory.
To allow greater flexibility we allow anyone with a score in Magic Theory, but anyone without the Gift have their total bonus halved. So if you can find a servant with Int +5 and have her learn alot of MT they can become very valuable despite the halving penalty.
If we go with Covenants rules (which I think are cool), then you have:
Assistant - needs to be Gifted
Familiar - marked separately, but still functioning as an assistant as per ArM5 rules
Person - someone who's there but isn't trained to help out
Servant - someone who's there for the purpose of helping
Slaves - a bunch of persons as manual labor or guinea pigs
If you want to have a great Mentem lab, a good way to go is to get a whole bunch of the smartest (Int>=0) slaves/servants you can buy/hire. Put in enough effort to make sure they know what they need to know to take care of the lab. Make sure they're happy enough (and perhaps scared enough, too) to never put a knife in your back. As long as you have the cash to feed and clothe them, you're set. If you'd rather have a balance of Corpus and Mentem, then you have the low intelligence ones hang out some of the time (Person) and make sure you have a bunch of more intelligent ones as servants (Servant) to balance the loss of Safety to the others. These are perhaps the only parts of those rules that are easy to abuse. I would probably force the player to choose between smaller numbers or having Slaves.
With the exception of the familiar (who I would see is like an extension of the mage), lab assistants must have gifts by the RAW. Servants, slaves, and other magical creatures provide bonuses like having specimens do (ie, easier I guess to do mentem labwork if there are minds around to experiment with or such).
OK. Let's try this again. I already listed several exceptions to needing The Gift. Here are the ones I know, all of which are RAW:
Familiars - we all accept this
Failed Apprentice - "You may not have the Gift... You may learn Magic Theory and serve a magus as a laboratory assistant." Can't get much more explicit than that within RAW.
Becoming - "The maga sacrifices The Gift... She may still cast spells and perform laboratory activities." That's fairly explicit, too.
I left out Gifted since that essentially gives the character The Gift, even though it may just be something similar; I figure that's might as well still qualify as having The Gift. I haven't been able to find anything specific on Homunculi. The can give others the ability to work in the lab, so they may be able to as well. I don't think I'll spend more time looking. There may be other exceptions.
Note that example 2 and 3 HAD the gift, something happened that they can't use it but enough remnants remained that they qualify. (someone could not become apprentice in first place to fail if they didn't have gift originally).
Yes, I agree: they had the Gift. They do not have the Gift, which was my point. Myself, I would use "have" or "had with remnants remaining" as the qualifiers for non-familiars.
Apart from the Familiar, the assistant must have or have had the Gift. The Gift isn't IMHO an either/or thing, you might have a damaged Gift or a weak Gift (or even a very powerful Gift). The damaged Gift was fine until some mishap, after which the poor sod can't cast spells or work on own lab projects, or even learn more of the Arts. But he can assist.
All of which serve only to strongly suggest that what is needed to assist the magus is an understanding of Hermetic Magic, be it via the Gift or a score in Magic Theory which, I point out, is only available to characters who have certain virtues anyway. I see no reason why to rule the Gift as being necessary though - the Gift is not the capacity to perform Hermetic Magic, but the capacity to be opened towards it - by the rules as written a Gifted Hedge Witch with Int 0 and MT 1 is more useful in the lab than a magical theoretician who has lived in a covenant all his life with Int +3 and MT 3 since he lacks the Gift itself.
Frankly, the magus who sacrifices multiple seasons to increase his Leadership skill and to hire and train his scholastic aides (who, let us not forget, are not faceless ciphers but companion level characters in themselves) deserves the middling boosts to his lab total. After all, he'll have to have something to balance the disdain his work will be regarded with, given that he needed mundane help even to get that far. You could require affinity with the Magic (or Faerie for Merinita) via some Supernatual Virtue or Flaw, I suppose, since the assistant will be helping in magically involved things, but the Gift itself seemsa bit much to ask.
Those restrictions basically mean that only other hermetic magi or your apprentice can help you. Add the familiar and there it more or less stops. Other traditions are unlikely to be seen as good lab assistants. Or sought after... unless they are part of exmisc, so we move to the first position. I find this ocverly restrictive, but reinforces the isolation of the hermetic magi and their paranoia. If this is a good thing (you like the lone magician in his lone tower) or not (you want hermetic universities amd research centres) is heavily saga dependent.
I tend to be leaning towarsds it being an unnecessary restriction, but that is me. I would give someone with the gift a flat +5 to your lab total if he has MT and a positive intelligence, which would make gifted lab assistants still way more worthy that ungifted ones, but if tyou want a legion of lab helpers, you can have them as well