Believe it or not, in all the time I've been running/playing Ars Magica the topic of talisman creation has never come up in any games, so I want to make sure I'm right on the fundamentals.
First, the magus prepares the item for enchantment as he would if creating an invested device, spending vis as required within his MT limit to enchant either the whole item or just part of it.
In a subsequent season the item is attuned as a talisman, but at this stage it is not possible to perform further attunements to gain benefits based on its form and material bonuses.
If only one part of an item was prepared for enchantment, it is then possible to enchant the rest of it bit by bit, and presumably this costs an amount of Vim vis to be determined by the Material and Size Tables on ArM5, p.97. Whenever this is done or whenever a power is invested in the talisman it is also possible to invest an attunement.
This is where there is a bit of discussion - My understanding is that it is not that he is "opening" the rest of the talisman, it is just that as his arts increase he can cram more vis into it.
Doesn't matter if he only opened the gem on a staff, or the whole staff.
Actually, I think it does. Presumably if one only opens the gem for enchantment there would be no form benefit from it being on a still non-magical staff. I'm guessing the idea is that the magus with a talisman made from a compound item has the advantage of being able to add bonuses one after the other, which must be kind of handy if you don't have enough Vim vis to enchant the whole thing at once.
Ok..I see where you are going but I would like to point out 'Greater Talisman': This mystery allows you to 'work in' new components'. This implies that you can actually ADD new things that were not in the item before. Ok..that seems straight foreward. Its crafting, but does not require a craft roll (magical effect).
If you take an item, enchant it, then make it your talisman, those things not included in the compound item would not be usable (mostly). Now you wish to expand it...Limited by the MT at the start, I would allow it. For any other type of item..no way...for a talisman, yes.
I would not allow him to add items not originally there unless he had the above Mystery. Remember, he is still limited by his MT, and the ability to add Vim Vis as you go implies that you can open the package slowly, instead of all at once...
8)
Well, how about an example. If my magus takes a wooden staff and spends 8 pawns of Vim vis to prepare it initially, within the limit of his MTx2 as with any other invested device, and then attunes it as a talisman, it would be possible in subsequent seasons to add, either gradually or all at once, another 12 pawns if his highest Technique/Form combination is 20. I presume it can be opened up for even more enchantments as his arts go up. Sound right?
There's a paragraph somewhere, I think under the talisman virtues in The Mysteries, that implies that once a Talisman is attuned, all of its bonuses count. Even if you only opened the highest-capacity part of it. This isn't a special effect of either of the mysteries described, either, just either a clarification of the rules, or a mistake.
I sort of imagine the attunement to the talisman spreads the enchantment out inside it, if it was initially focused on one piece.
If the item is opened as a compond item, then all the components count (this will require vis equal to EITHER the largest (in terms of vis-cap) component, or the sum of all components).
Any components not initially opened (either because of lacking vis, or because the limit of number of components (equal to MT) has been reached, can not be attuned.
Great Talisman allows new components to be added, both previously unopened parts of the talisman, and new stuff you add to your talisman.
I agree with Ulf. I seem to have mis-stated my understanding. If you open an item as a compound item, but you only open the most expensive part, you get all of the S&M bonus' of the components. The "Magic" or Vim is only in that one part. As your arts increase you can squeeze more magic into that part, but you cannot put magic into the other parts.
*** Forgive mistakes in the numbers, I've not got my books ***
e.g. A wooden staff (2 * 4 pawns), Gold jewellery (2 * 10), 1 gem (1*15)
So I can open the gem for 15 pawns. If my MT is 8 or more.
If my highest arts are 20, I can stick another 5 pawns of vis in.
However, if I opened up the other components one at a time or altogether I could stick in 43 pawns total.
This is the difference between the two - if it is a talisman, even if it is a small piece of wood, you can stick enourmous amounts of vis into it.
If it is a compound item you can stick in as much vis as the components will hold. But whether it is a Talisman or not, you cannot open up other components after it has been opened.