In Ars Magica it is trivially easy to create a min-maxed character, I think everyone here has done it in one shape. There is a fine line between creating a specialist and creating a min-maxed monstrosity. I can't tell you exactly where that dividing line is, but when I see it crossed I know. I don't want to have a lot and hard and fast rules and say no to a lot of things, but I do want you to have powerful in character motivations for certain choices and be able to defend those choices if asked by anyone in the troupe.
Players should create individual character threads for all of their characters, at first we're starting with instructors as they will take the most time to make. I'd like to see a snapshot at gauntlet and every 10 years or so post gauntlet. If you have MetaCreator you can send me the files.
This is an opportunity of creating characters that are otherwise sub-optimal. I once created a character with Unstructured Caster and Rigid Magic making formulaic magic impossible. I might even bring him here as my SG player character, or someone like him, just because this is the perfect environment for someone like that.
If you're going to pursue mystery cults, we'll work through those as they come up in your character development threads. Mystery Cults will unlock things, but often at the expense of experience points.
The only solid guideline is that your character needs to have the minimum combination for teaching of Com + Teacher + Virtue>=7. 40 xp per year for advancement and all spells are purchased with experience points (this removes the need of asking me whether a lab text for a spell is available).
Additional character building rules
Buying a LR
(Normal vis cost you would pay) + (1 per mag up to 10) + 2 per mag from 11 to 15) +(3 per mag from 16-20) + 1 season of XP sacrificed.
Characters get 5 build points worth of stuff per year. So for the typical 30 years post gauntlet character, they would start with 150 build points. It sounds like a lot, but it's not, not really when you consider some of the restrictions.
Vis
This is probably the crunchiest part of determining how much vis a character has, especially when used to compute the longevity ritual. [strike]During generation no more than 10% of your available build points at a given time can be in vis, and it is limited to an overall total of 100 pawns of used and possible vis for everyone during character development.[/strike] During generation no more than 10% of your available build points at any time can be spent as vis. Say your magus gauntlets at age 25, and acquires stuff for 10 years, and wants an LR at age 35. Such circumstances give him 50 build points, he can convert 5 build points to vis, for a total of 25 pawns. With 25 pawns of vis at age 35 he can buy a LR of: Ritual 7 + 101 magnitudes +42 magnitudes, or a total of LR 14. It's a pretty good LR. When he musters out, so to speak, and starts the saga he can also only 75 pawns of vis. It's possible that some characters, depending on their age at gauntlet might need two LRs due to not having enough vis at age 35, but that's not unusual in play, either. The first LR is usually the hardest to come by unless one's a specialist, and even then, a specialist will often redo the ritual later on.
Summae
They are generally off the table. I haven't posted this as a house rule, but basically Summae in Arts are primers for new magi in this saga and can't go past level 7. High level and high quality Summae are the debbil. I hate them as an SG and love them as a player. If you have an Art score below 7 at the start of the saga, we can talk about finding a summa, but that would be the exception. They would cost the standard build point cost, and have the standard build point limit. In many cases a tractatus might be a better fit. Summae in Abilities are multi-volume sets, and I need to tweak this a bit, but still it will make my life a lot easier if you don't try and bring the L6Q12 book on Parma Magica and the like.
Tractatus
These are available, but you may not bring more than 6. Of these, if these are in your favored Arts you may have already read some of these, but they will have other uses later on, such as trading them to the other professors. If all 6 are in nothing but your favored/highest Art, you can be sure that you've read some of these.
Items
You can and should build items with the bulk of these build points. These aren't necessarily items that you've made, but items you've acquired or traded throughout your life post gauntlet. I may veto the Wand of Ball of Abysmal Flame with +30 penetration, as I want these to highlight how a magus will use magic to improve the comfort level of his surroundings make his life easier and the like.