Salve Soldales!
If I'm being helped in the lab by my own familiar and another gifted person…
and that lab assistant has a familiar…
And my leadership is at least 3…
Can the lab assistant’s familiar also assist me, adding it's intelligence + magic theory to my lab total?
Yes. No. Maybe.
There are different opinions on if that should work, and no clear answer in the rules.
I have always played it as yes!
This has been debated a number of times in this forum.
So, on the one hand, under Help in the Laboratory, "Anyone who has the Gift and a score of at least one in Magic Theory may help you to perform any activity that uses your Magic Theory", and the lab assistant's familiar does not have the Gift.
On the other hand, under The Bound Familiar, "[bound familiars] can learn Magic Theory and serve as laboratory assistants, even though they do not have The Gift".
The interpretations I've actually seen are:
#4 is pretty rare.
Note that if you pick anything other than #1, and you have Folk Witches running around, you may have to decide if their familiars can learn Magic Theory and assist magi in the lab. Even if you allow that for the familiars of Gifted Folk Witches, you may want to disallow it on the part of the familiars of unGifted Folk Witches.
I think at some level it comes down to how you treat the idea of an assistant to your assistant.
For example in covenants you are able to make minimal use of a servant in the lab with no Gift or skill in magic theory- gaining the servant’s Int/2 as a bonus. There is nothing to say that a second servant could not be assigned to your assistant, though whether the lab total would benefit or not is not explicitly stated. To me the familiar of an assistant is in a similarly uncertain state that is really a SG decision.
Alternatively, you might want to require to have a Leadership score.
By default, a magi can have a familiar and an apprentice "for free", any additional help would require one point of Leadership. At least, that would be consistent with multiple helpers assisting the magi in a laboratory activity.
You are misremembering Covenants.
Servant: +(servant’s Intelligence / 2, rounding up) Safety, +1 Aesthetics; +1 Me. They do no provide a bonus to Lab Total, outside of increasing a Me Specialization (if one even exist). Their modifier is to the Lab’s Safety. Other possibilities for people in the lab listed in Covenants are ‘Person’ and ‘Assistant’. Person gives -1 Safety and +1 Co or Me. An Assistant uses the rules in ArM5 and actually adds to the Lab Total.
To be a Servant, they must specifically be a full-time lab servant. A maid who comes in to clean your lab frequently (1 hour, most days) would qualify for the Person Virtue.
Oh and there is also the Guard Virtue, but is for someone at the entrance rather than in the lab. A guard stationed in the actual lab would use the Person virtue rather than the Guard virtue.
Great reply, Troy 
. These Person example actually clarify things up 
I think this comes down to how min/max you want to go, as multi lab assistants can give a big boost. Getting a leadership of 3 is not too hard. 2 seasons with a decent teacher gets you there. Int +2, Magic Theory +4 assistants would not be too hard to find. +18 to a lab total is pretty extreme. Also, are we saying 3 adequate assistants are better than a master assisting? There should be some dimishing returns for extra people.
I’m generally not a fan of this degree of power creep, as if 1 person starts wringing every number out of the books they can, every other player has to, or be left behind. If everyone likes getting big numbers, and spending the time in the rule book great. Otherwise I’d be shutting down multi assistants. I’d suggest saying only the highest int adds. For Magic theory, add all the XP of the assistants together. The level the XP total gives is the level added, not the individual levels added together.
Normally, only magis or apprentice can assist in laboratory work. Servant, as Troy mentionned, don’t give bonus on General Quality, only on safety.
So convincing fully competent magis to personally help or lend their precious apprentices, although not forbidden or impossible, requires a high level of trust but also admitting that the lead magi is their superior.
You can handwave that part if you just want to min-max, but I know for sure it won’t fly that easy around my table. Some PCs might be willing to help another PC on personal project, but it will be more the exception than the rule.
The point is that if you allow an assistant to assistants then every magus helping you could have their own familiar and apprentice, and the lab safety total can go through the roof by providing everyone with servants. Now your magus with there leadership has 3 other mages, 4 apprentices and 4 familiars. Allowing helper’s apprentices but counting them against the leadership limit is probably reasonable for most campaigns, which then circles us back around to the main question- can the assistant’s familiar help and will they count against the leadership total constraints?
Or do we follow a more “military” stucture where a “general” with leadership 5 can have a team of 5 “commanders” each with leadership 5 who in turn have “captains” with leadership 5? It works conceptually for a military where your general commands, indirectly, 125 men (or larger with more layers of command), but doesn’t seem like a good idea for a lab, even aside from space constraints.
The question is not really about any “assistant to assistants”, but if someone else’s familiar can assist you in the lab - with or without their mage also assisting.
If they can, yes of course they would count against the Leadership score. Even your own familiar normally counts against the Leadership constraint, though with an exception for low scores.
This is one of the quirks of the rules. Even if you can get a master mage to help you for a season, they aren't really much more use than someone junior (but with decent training in Magic Theory).
I don't think this should be changed, actually. But it does appear that Hermetic magic is really bad at cooperation work. I guess that's what happens when your founder is a genius.
When I said master, I should have said expert. To my mind, there is only so much help another person can give, and having 3 or 4 people in a lab, if anything they will start getting in each others way.
I think that's where the Leadership comes in. But the rules don't say much about how lab work is done, so there's a lot of latitude here.
But imagine two senior magi in a covenant, both with Leadership, apprentices and familiars, and with labs side by side. If they are cooperating on a single research project, that ought to be a big advantage, and the rules don't allow for that. That may be for the best: it would change the flavour of the Order a lot of all major advances were team efforts.
Exactly. And as I mentioned above, if 1 magi does this, then everyone does, or they fall behind.
Power creep is a big decision, as it changes tone. An example. A long running sage could employ a mundane teacher, and give them a longevity potion. Good teaching, affinity teaching, etc. Regularly getting 30 XP a season is plausible.The mundane teacher teaches the magi teaching as well. When a magi gets a new level of magic theory, arts liberales, philosophy, concentration, etc they teach the teacher, who then teaches everyone else.
There has been much discussion in other threads about books. Arguably the Order should be awash with Quality 8+ tractatii, such that 1 vis for 1 would be a reasonable cost. Power creep again.
I appreciate this has gone a little off topic from the first post, but I think the first post opens a door to the bigger power creep discussion.
The fact is that you don’t even have to use lab assistance rules for combined projects to work- lets say we are trying to make a breakthrough. When one of us makes progress we have lab notes both for the inspiration and for the development for breakthrough points, which we can share with another mage who can then follow the same steps more quickly. If we are both making progress towards a breakthrough and just share our lab notes we can get there more quickly with two magi working on the project instead of one. Cooperation actually inside the lab is a much more specific issue, and for the most part already part of the rules and setting aside from the issue of prestige loss, which is a sort of slapped on patch to explain why the order isn’t far more powerful than it is.
as to a familiar’s bonus it states that a magus may always have one more assistant other than their familiar, not that the familiar must count against the leadership total. I have seen arguments either way, most centering on the fact that with familiars counting you have to have a leadership skill of 3 to actually gain anything from leadership. Personally, I would definitely not allow another magus familiar to assist in the lab without the other mage being involved. While I would not count a mage’s own familiar against the leadership total I would count anyone else’s familiar. I can also see where people who are trying to encourage or discourage more cooperation might make other choices.
For breakthroughs, yes, you can share insights. I was thinking of non-breakthrough effects that are just very high level.