Something came up recently in our troupe: is it OK for a magus to bind a potentially very powerful magical beast while still very young and small, and raise it, thus winning, a bond with an entity potentially to powerful for the magus to bind as an adult?
On a certain level, my gut tells me this is a loophole in the mechanics. On the other hand, the magus is going to have much more work with the familiar story-wise, having to spend time educating it. They will also have to deal with the parent of the familiar, usually.
What do you think? Do the rules say anything on this? On another note, do creatures with Magic Might start with lower Might when young?
That is the question for your SG to decide for a specific creature. It might make sense for dragons and such.
The troupe then decides, whether such a creature remains bound as a familiar, if its newly increased Might leads to a (ArM5 p.104) Familiar Bonding Level overcoming the previously achieved (ArM5 p.104) Familiar Bonding Lab Total.
I would be doubtful: the Familiar Bond could not by itself now keep the creature of higher Might bound - but there may be special situations of established deep friendship that the troupe - and the creature - might accept.
By ArM5 p.104 you can strengthen your Familiar Bonding Lab Total as time progresses, though, and maybe - instead of increasing cord strengths - thus keep it strong enough also to bind the creature with its higher Might now.
The Rules don't say anything specific about juvenile familiars that I'm aware of. The closest they come is
[quote="Core Book pg 105"]
The familiar will not die of old age as long as the magus is alive, and it only suffers ill effects from aging when the magus does. [/quote]
If you wanted to, you could extrapolate from that that the familiar only ages at all when the magus does (so if the magus has already matured, which they almost certainly will have done, the familiar will be stuck as a juvenile and unable to mature), but I don't think it's required.
It would be reasonable to have the magus have to keep the bond score above the minimum that would be required to bond the familiar at the current point in time, but again it's not required by the standard Rules.
There is also a mention in GotF that Philipus niger convinced a basilisk to give him one of its eggs so that he could raise it and bind it as a familiar. It is not quite clear if he bound the basilisk as a familiar when it hatched or if he waited until it was fully grown. There is clearly the possiblity that he bound the young basilisk and that it grew up while being his familiar.
There is excellent story potential in a familiar growing up. Which is itself sufficient justification to allow it, for me at least. It is my impression that most magical creatures grow and sustain themselves by consuming vis that takes the shape of their natural food source, such as magical plants for herbivorous animals and magical animals for predatory animals. So there is that to consider. Your familiar would have to consume rather large quantities of vis if it were to grow to maturity according to the rules presented in RoP:M.
That would be my reading. If the familiar's binding minimum grows beyond the lab total, the bonds would start failing. For most magi this won't be a problem, but if you're binding a Might 10 griffin cub of Size -1 and it will grow to a Might 45 adult of Size +2, you might have problems.
Since any creature with Magic Might can potentially grow in Might over time (by consuming vis), this has the potential to be an issue for any familiar.
On the other hand, you could go with the elephant rope:
the story goes that a man visiting the Ringling Bros circus saw an Elephant on a rope staked to the ground. The rope was but 1/4 inch in diameter, and the man looked at it confused before asking why the elephant doesn't simply break the rope. he is told that the Elephant has been tied down with that rope since it was a child, when it was too small to be able to break the rope, but fought against it until it learned that it was futile to pull at the rope. and so it no longer tries to fight the rope.
Similarly a familiar bound at a young age which has grown in power might remain bound by a weak bond simply because it is accustomed to being bound.
Or perhaps in its growth it has strengthened the bond itself...
Not saying that these are RAW, but different perspectives which could work.
Maybe, but I'd hesitate to characterize the familiar bond as a restraint. It makes Acclimation irrelevant, often provides extra powers and a True Friend, plus the relative luxury from living in the wild.
Normally I would agree with you but it does depend on the critter in question. For a low powered creature with a short (expected) life-span your analysis 100% holds true.
For more powerful creatures it can become a problem that the familiar dies along with the magus.
It is an interesting dynamic to consider because if you are trying to bind a low powered familiar as a magus you are in the position of doing the prospective familiar a favor but if you are trying to woo a powerful familiar the situation is probably more the opposite.
Just because a lot of magical creatures might have to age along with their magus that doesn't make it that bad a deal. Magic critters get killed in the wild all the time - by magi, by other critters, by accident. If it's a choice between definitely dying in 150 years, or probably getting killed violently within the next 10 years but theoretically living forever, what's the right choice? Those Might 40-50 creatures aren't likely to get killed, so yes, those creatures are less likely to be interested in becoming a familiar.
But the rules for familiars were written long before RoP:Magic came around, where magic creatures weren't necessarily immune to normal aging. As written in core, it's beneficial to the animal as it assures that they won't age to death before the magus does - a magic mouse would only live a few years if it aged like a normal mouse, which was the assumption that RoP:M turned on its head. Familiars also didn't have the might related learning penalty until RoP:M came around, it really changed the rules significantly.
Plenty of magic animals probably do have Susceptible to Deprivation and Age Quickly flaws, making them age like normal animals. The familiar bond is very attractive to such creatures. As for the ones that are ageless, they should probably remain ageless - those rules wouldn't apply to spirit, daimonic or faerie familiars either.
If I were to have a Familiar evolve and grow, it'd be for story purposes, where the player in question, SG and actually the entire Troupe are in agreement about wanting it.
I could see a young, inexperienced magus bonding with a young familiar, because it it easier than with an adult.
Then, as the Familiar grows, it will reach a limit where the Might reaches the level of the Bond. Increase in size may also affect this.The magus must then continually study his Arts and at some point reforge the bond (perhaps even more than once).
If not then the Familiar either suffers and is held back, because the Bond level is a limit, or some powers and enchantments may temporarily become unavailable.
Or one could rule that the animal breaks free if the Might exceeds the Bond level, perhaps set some limit like 5 Might or 10 more then the level, to give a buffer. It seems too final to have the familiar break free. Of course it could be a temporary thing, where the bond isn't broken, but the connection is weak, and the familiar is away and no powers or effects can be used.
It will become a race to keep the Familiar well. Perhaps use story elements to seek out special auras or find vis to feed the animal to stave off ill effects etc.
So, what I've pieced together from the discussion:
magic beings do not grow old and die as a general rule, but exceptions may exist
there is RAW evidence of magical beings growing up, and gaining power
This deifnitely makes it possible for the PC magus to bind a juvenile familiar, and it should be easier than binding an adult. As for handling the growth of the familiar, I really like the idea of the bond "stretching" for a while, and putting strain on the familiar, and after a certain level discrepancy, simply fraying. This motivates the magus to take actions in order to preserve the bond, and provides for interesting stories. I think I'm using this.
You say 'as a general rule' and 'exeptions may exist', but I think there needs to be a slight bit of clarification here. I did a LOT of work with familiars and magical animals this last November. Magic Beings do not grow old and die as a specific rule. This is because magic beings constitute Magical Animals, Magical Humans, Magical Spirits, and Magical Things. As a policy, almost every Magical Animal (which are what can be bound as familiars) and Magical Humans have Succeptibility to Deprivation. In fact, in the RoPM book, there is one animal without it, and one human without it. So while it's not forced onto the character build, I expect most Magical Animals to need to eat, breathe, and age.
I also like the idea of having the magical bond stretch and fray. Maybe start taking away points from the cords as it gets bigger or mightier. (I know it doesn't work like that, but its counterintuitive). It may also be worth considering that a juvenile might not be able to truly make a lifelong-friendship-dedication necessary for the familiar bond, though YSMV. I'd probably not let any familiar bonding happen until it was at least young adult if not fully grown.
I think you miscounted: the salamander and several cats (not fully statted, but that's not listed among the common Inferiorities).
If you look at more than RoP:M (and I'll skip stuff before it), you'll find more examples without that Inferiority. For example, I couldn't find a single Familiar in Through the Aegis with it. So it does not seem that is the intention across the line, even if it had been the intention of some writers of RoP:M.
This Inferiority has nothing to do with aging. Aging falls under a different thing. The description of the Inferiority even says all this explicitly: "The character is still immune to aging, unless it has the Age Quickly Flaw."