On page 97 of ARM5 the material & size table is where you decide how much vis an object can hold correct?
What is page 110, shape and material bonuses about? Is this how much extra vis an item can hold or some kind of bonus to rolls?
Please someone walk me through 5 mages casting aegis via wizard's communion.
This page is about bonuses related to experimentation, when you enchant a device and the shape/material aligns (pick the highest one, limited by Magic Theory score) you can add that bonus to your lab total when enchanting the effect. It also applies as an attunement bonus for the Talisman when you attune the talisman for a specific bonus.
Let's presume that this is an Aegis 25, since you're working with 5 magi; this example also presumes that the Aegis must penetrate, otherwise Communing is unnecessary.
To commune the communing magi must know Wizard's Communion at high enough level to double the level of the spell. An Aegis 25, requires combined communion levels of at least 50. Note, that Muto Vim has corrected via errata and a Sun Duration Wizard's Communion is necessary (some troupes call it Ritual Communion), that reduces the levels added by 10 per magus due to Sun Duration, the effective minimum level for this spell is 15th level, but for power purposes to the Communion it only adds 5. So, in our example, if everyone contributes equally, they have to know Ritual Communion 20, and each adds 10 power levels to the spell, for a total of 50, but anyway you can get to or exceed 50 is valid.
The Aegis 25, via Wizard's Communion for 5 communing magi has an effective level of 25 (spell level)/ 5 (participating magi) or 5. So when rolling for the final result, The penetration difference is Casting Total -5, rather than Casting Total -25.
For 2, at the starting level of play you are at, the shape and material bonus is essentially a bonus to enchanting magic items.
Say you want to make a magic wand that can move objects at a distance....
Let's give our example magus a score of 10 rego and 8 terram (rego being the art to move an object, terram being 'Earth', but also being used for bulk movement of objects no matter their material in some sagas), a magic theory of 4 (not a bad starting score) and an int of +3.
Let's put them in a lab with an aura of 4, and a bonus (assuming you've got covenants to cover all that) of +4 for making items.
Your lab total is 10+8+4+3+4+4 (Rego+Terram+MagicTheory+Int+Aura+LabBonus) for a total of 33. However, because you're using a wand, you also get to add a shape and/or material bonus to it. Let's work out the enchantment, and we'll assume 1 use per day for simplicity.
We'll go with a base 3 Rego Terram effect. We'll give it a duration of concentration for +1, and an additional range of sight for +3. This results in it being a level 15 effect (3+1+3 because of the way Ars Magica works goes 3, 4, 5, 10, 15.) and is essentially a range sight version of "The Unseen Porter" (AM5 Page 156). This effect costs 2 pawns of vis (rego or terram vis) to enchant as a lesser enchanted item.
A wand gives a +4 bonus to controlling things at a distance, resulting in a lab total of 37. Knowing this in advance, you can adjust your effect design using the rules from pages 98 and 99 to allow for more uses per day, penetration on the effect, and other triggers. For a lesser enchanted item, your lab total must at least double the level of the finished effect. 37/2 results in 18 (rounding down), meaning we can add 3 levels to the effect, maximum. Assuming this wand is simply for ease of moving objects, and is therefore akin to a magic forklift truck prongs, we don't need penetration. Being able to use it multiple times a day could be handy, and for our spare +3 levels (added as levels, not magnitudes), we can add 6 uses a day (see the table on page 98).
Our effect's level is therefore 18, and our lab total of 37 is at least double this. In a season we get to enchant the effect, using up the 2 pawns of vis and the premade wand. We now have a wand that can move any object it is pointed at that a man with strength of +5 could move, up to 6 times a day, as long as we point the wand at it and hold the triggering effect.
Being the sort of cautious, user proofing chap I am, I tend to make sure the activation sequence isn't something you can do by accident, but is designed to be doable by anyone once taught. I would thus have it set up as a sigil on the wand that you press and then speak the command word while aiming at the target. Releasing your finger or thumb from the sigil ends the concentration and thus the effect.
Magic items become mildly more complex if you have a Verditius, and I recommend reading page 93 thoroughly on the subject. Basically, Verditi can make items cheaper, and don't necessarily need the item to be made BEFORE they enchant it so long as they have the raw materials. They can also get bonuses equal to their philosophae score (capped by magic theory again).
When you create an enchanted item, you take the values for the "Base Points" of the material x "Size Multiplier", and that is both 1) the number of pawns required to prepare an Invested Item for enchantment, and 2) the maximum number of pawns that your item can hold for a Lesser Enchantment.*
(* So some small, inexpensive items cannot be made into more powerful Lesser Enchantments. A small "gem" of glass can only hold 1 pawn, 10 Levels of lesser enchantments, everything included.)
(Note that there is also always the limit of "max pawns/season = Magic Theory x 2" for any mage (p 94, col iii, "Vis Use", and p 97, col iii, par 2 end, and this step of an enchantment must be done in one season, whether as Lesser Enchantment or Preparation for an Invested Item. It takes a mighty mage to prepare some larger, highly valuable items.)
However, note also that there are 2 (well, 3*) different ways to calculate the final total, and the possible S/M Bonuses involved - for "Part of an item" (also used for a simple, single item) or for a "Compound Item". These 2 methods are discussed on page 97, under "Preparations for Enchantment".
Basically, if you are going to enchant a single "thing" - an iron sword, a silver skull, an amber mask - that is straightforward, the item's Material x Size = pawns. But if you are creating an Invested Item you can also "add up" different parts to create a compound item - an iron sword with a silver skull on top with an amber mask on that - you add each of those to find the total and prepare them all together for enchantment as one, possibly very high-capacity, item. Compound items are more commonly something like a staff with something attached/embedded, or a ring with a gem, or something along those lines. Note that this preparation still has to be done in one Season (think "limit = Magic Theory x 2 pawns"), and that compound items are not appropriate for Lesser Enchantments!
(* The 3rd type is a Talisman, but that's a special case. See page 98.)
See p 97-8 for a full walk-thru.
BL laid it out well, above. A couple points...
It's possible to include only 1 Shape Bonus plus only 1 Form Bonus, for a total if both apply. So, if your mage wants to make a "silver sword" to kill werewolves, he'd get +14 on his/her Lab Total - Material = Silver (+10 harm Lycanthropes) and Shape = Sword (+4 harm human/animal). (And, yes, some few combinations can give a large bonus to create small Simple Enchantments.*)
But they could not get a +10 from panpipes to "control children's revelry", nor could you compound a staff with a bow for +9 to "destroy things at a distance" - both those examples involve 2 Shape bonuses, not allowed. Similarly with 2 materials in a compound item - one Shape, one Material, for each enchantment. (Diff enchantments within the same compound item could draw on diff bonuses, nothing wrong with that.)
[i](* Also, the total Bonus cannot exceed Magic Theory (p 99, col iii, 2nd bullet point).
Also, S/M applies to the LT for that season, not to each item itself, so creating a half-dozen items each with +5 bonus adds +5 to LT, not +30 - even if you had the MT to cover that. If creating different items with different S/M totals, the Troupe has to rule whether to take the largest, smallest, or what - it's not clarified in the rules.)[/i]
As to what constitutes a "Form", many Troupes rule that "the image" of a thing = a Shape - so a ring with a skull on it could be enchanted as "a skull", a robe with a sword embroidered on it can count as "a sword", and a dagger with a cat etched on the blade could be enchanted as a dagger or "a cat" - at least as far as "Shape Bonus" is concerned. ysmv.
Edit - OH! And don't miss these wonderful compilations in .pdf form, found on the Atlas/Ars Magica main page (atlas-games.com/arm5/ - right hand column, half-way down)
atlas-games.com/pdf_storage/ ... yBonus.pdf
atlas-games.com/pdf_storage/ ... yShape.pdf
[list][list][list](courtesy of Erik Tyrell - credit where credit is due.)[/list:u][/list:u][/list:u]Note that in canon, these are all the S/M Bonuses that are (publicly) known to The Order. There are rules for inventing more, and it's not that hard (a season or few), but as defined these are what "currently" exist. ysmv.
Isn't the Shape and Material bonus limited by your Magic Theory score?
So in order to get the +14 to harm lycanthrope you would need a Magic Theory of 14 right?
True, your Shape & Material bonus for enchantment is limited by your Magic Theory.
Note that IIRC, your attunement bonus from your talisman is not (though you can only use one attunement bonus in a single spell casting total).
A magic theory of 14 is actually possible.
True, forgot to mention that, thx - edited in, above.