Explain Arcane connection simply

I have tried to read Arcane Connection rules several times, but still it is bit shady for me.

Lets take two examples.

There are covenant member who should be found, target is dead. There are some personal items in the covenant like clothes, a comb, special ring (just normal) from his parents and of course his place of living.

How locating works? How to calculate? What multiplier means?

Second example.

Magi wants to see through the eyes of the target. He don' know where the target is. He is another magi with the Parma Magica 2. Magi who tires arcane connection knows only the name of the magi and what he looks.

How calculation is done then? What are the chances to cast a spell?

An Arcane Connection is something connected to another in a mystical way. Arcane connections (AC) are useful, because they allow you to target unsensed targets, targets at a great range and also provide a bonus to penetration if the target has magic resistance.

In the first example, that's probably a saga specific thing, but items that belong to someone wouldn't be an AC to the now corpse, IMO. They might be an AC to the ghost, if it exists. Now if you had hair in the comb, yeah, I'd say that's going to remain an AC to the corpse. YSMV.

The second example is a bit more involved and requires a bit of arithmetic, and making some assumptions in addition to the information you provided.

An AC can be used to cast the spell at great range, and also provide a penetration bonus. Magus A knows the spell to do so, and has an AC to Magus B. Magus A casts the spell, and he needs to have a penetration bonus greater than Magus B's Magic resistance which is his Parma score x5 + Imaginem form. Say he has an Imaginem score of 5, he has a resistance of 15 against that form.

Penetration is calculated by first calculating the excess of Casting Total - Spell Level. In this let's assume it's 9. If the caster has the penetration ability, that is normally added to the remainder above to determine total penetration. However, when you have an AC, you can multiply the penetration score. Let's say he has a penetration score of 2, and the AC provided lasts for weeks or months so it provides a bonus to the multiplier of +2, which always starts at 1. So the final penetration is 6 [excess of Casting Total - Spell Level] + (2 [Penetration Ability Score] * (1+2 [multiplier for weeks or months duration AC]). Simplifying the equation it is 9+2*3=15. The penetration matches the resistance of the target (which was 15 from above) and the spell fails to take effect (penetration must exceed magic resistance). Of course, he could use confidence to boost the final casting total, and therefore affect penetration to have the spell succeed.

Calculation penetration is a bit tedious. At it's simplest, without an AC, it's just Casting Total - Spell Level + Penetration Ability

How pinpointing is done, by spell?

Pinpointing is done by the spell and the Arcane Connection. The spell must have Range: Arcane Connection.

What is needed to establish it?

Multipliers won't affect if spells are cast to normal people without Might or Magic Resistance?

Every spell can be resisted by might or magic resistance?

Is it possible to cast "Crystal Dart" spekl on target if normally that spell needs eye sight to cast?

Nothing, Arcane Connections to the target are automatic, and listed in the chart on page 84 of the core rule book.

Multipliers aren't needed against the mundane, they have no magic resistance. Might provides magic resistance equal to the might. It is possible to have spells that have negative penetration (casting total - spell level= negative number) and they still affect the mundane, but they will fatigue the caster.

Yes.

Hermetic Magic requires targets to be perceived without an AC. Sight is but one sense, you can possibly hear the individual, too. But assuming you can't perceive them, but you know that they are in range, I think it's reasonable that with an AC you can target someone with the spell, but I can understand how such an interpretation might be difficult for some troupes to accept. It's something to discuss with your troupe.

I know you are looking for an explanation of the rules.

This is not what I am going to write about.

What is an arcane connection?

When I was five years old, my father carved a wooden knife for me to play with.
I still have it. And I treasure it. If I should die before my parents die, my parents will find this piece of wood between my belongings. They will know what it meant to me. This is an arcane connection. This is not a metaphore. I keep this piece of wood close. And I will for fifty years to come...
Yes, really.

There is hundreds of things that are arcane connections to me by Ars Magica rules. Half a liter of my blood. Pieces of hair in my shower that I did not collect and burn. Clippings of my tooth nails and such. My forearm if you chop it off of me. A couple of easy to obtain things I wont mention here.
Guess which one is closest to me...

So, please, forget about the calculations. I know mechanics can help. But that is what they are: helpers.
Arcane Connections are much more than a variable in penetration total calculation. And sometimes the calculations make you loose focus.

Think Story.
Think what it would mean to you, personally.
Think Story again and forget about the rules.
This is a "feel it" thing really.

I know this is probably adding to the confusion. But sometimes mechanics can really get in the way.

This is a game dangnabbit, not a math class...

And this is a very personal opinion. Use, abuse or discard as you see fit.

Yours sincerely,
Fury

Arcane connections are established by a variety of means, be it emotional attachment or physical attachment or similar. There is a list of the kind of things that can be arcane connections on p84 of the core rulebook, in the box labelled 'Arcane Connections'. As you can see on that table, Fury's wooden knife would indeed be an arcane connection were you able to get your hands on it, but a lock of his hair would be a more effective arcane connection.

Magi don't create arcane connections, they find them. The easiest way to get an arcane connection in the field is to steal something belonging to the target or to take a chunk out of them. For example, if a grog manages to wound a beast with his sword then the blood on his sword is an arcane connection to the beast.

What a magus can do is fix an arcane connection. This is a seasonal activity that involves taking an existing arcane connection and msytically preserving the bond it has to the target. Thus, if you took Fury's wooden knife and spent a season fixing it as a connection, the result would be a mystically stronger connection than a lock of his hair or a pint of his blood.

Penetration multipliers for arcane connections (and sympathetic connections) are purely about overcoming magic resistance. If the target doesn't have magic resistance, none of this matters.

No, not every spell. Magic resistance applies if any of the following are true at the moment the magic resistant target is affected:

• the spell directly targets the creature with magic resistance (e.g. an Intellego spell to look through someone's eyes)
• the spell creates something magically that then affects the target creature (e.g. Pilum of Fire)
• the spell modifies or controls something that then affects the target creature (e.g. The Crystal Dart)

It is worth noting that any spell you can effectively cast via an arcane connection will be resisted. You can't cast 'Pit of Gaping Earth' at the feet of someone to whom you have an arcane connection unless you can see / have an arcane connection to the ground he's standing on. Pit of Gaping Earth doesn't target people, it targets ground.

If the spell range is 'sight' then the target must be close enough that the caster could see them if no obstructions were in the way. In addition, the caster must be able to sense the target OR must have an arcane connection. So if, for example, you have an arcane connection to a guy who is on the other side of a wall, you can target him just fine.

If the spell range is 'eye' then you must have an unobstructed view of the targets eyes and they must be looking into your eyes. Both of you must be able to see the other. This is intentionally very restricting; it's designed for 'look into my eyes...' spells, and is typically useless for combat.

To go back to your original post...

Example 1:
A spell of range 'Arcane Connection', such as 'The Inexorable Search' could be used to locate the covenant member. As long as the spell has a range of 'Arcane Connection' it'll work just like any other spell. Assuming the covenant member does not have magic resistance, none of the multiplier stuff matters.

Example 2:
In this case the Magus is out of luck. In your example, all he knows are the name of the magus and what he looks like. While these can be used to create sympathetic connections, neither of these are arcane connections. No arcane connection means no spell targeting.

Now, if the magus has also got an arcane connection (a lock of hair), then...

A lock of hair has a penetration multiplier value of +3.
The magus also knows the name of the target, which is a sympathetic connection of +1.
The magus also knows what the target looks like, so if he creates a symbolic reference such as a small doll then that's another +2.

This gives a total penetration multiplier bonus of +6. We add this to the default penetration multiplier (1) for a penetration multiplier of 7.

The caster now attempts to cast the spell. Lets assume, for argument's sake, that he manages a casting total 2 points lower than the spell level. This means the spell goes off, the magus loses a fatigue level and the penetration total is currently -2 (casting total - spell level = -2).

Lets assume that the target has a relevant form score of 5 and is standing in a +2 magic aura, so his magic resistance is 17.

Now, lets assume the caster has a penetration ability score of 3. The final penetration bonus is penetration ability x penetration multiplier. The default penetration multiplier is 1, but because of our penetration multiplier bonus, the final multiplier is 7 (1 + 6 = 7, as calculated earlier).

This means the penetration bonus is 3 (ability) x 7 (multiplier) = 21.

We add this to the current penetration total (-2), for a final penetration total of 19 (-2 + 21 = 19).

Because 19 is more than 17 the spell successfully penetrates and takes effect. The caster is now able to see through the eyes of the target.

If the magus did not successfully make a symbolic reference, his penetration multiplier would be 5. This would mean his final penetration would be 13 (-2 + (3x5)), which would not be sufficient to overcome the target's magic resistance and the spell would fail.

All of this assumes the spell being cast is of range: Arcane Connection. If it isn't, it's not going to work because the target is out of range.

As an addendum, there is a way to cast spells with ranges other than Arcane Connection on a distant target to whom you have an Arcane Connection. To do so requires the spell "Opening the Intangible Tunnel", on Core p. 162. This allows you to cast any spell of range greater than Personal on a target to whom you have an Arcane Connection. Both "Opening the Intangible Tunnel" AND the spell you wish to cast must penetrate, and you must also maintain concentration, so this is not easy. OIT is a general spell, which means you can invent it at multiple levels. The spell you wish to cast through the tunnel must have a level less than or equal to that of the version of OIT that you are using.

One question I have is whether one could create a magic item that could cast Opening the Intangible Tunnel. This has major disadvantages, chiefly, the inability to take advantage of the Arcane Connection you possess for penetration, but it might allow you to avoid the need to maintain concentration yourself.

It is.
Though arguably, depending on troupe and the design of the specific item, you might need aditional magics to sense the Intangible Tunnel and thus be able to cast spells through it.

Also, depending upon the end use, consider using D:Diameter, rather than D:Concentration on the spell. If it's for contacting your grogs at a distance, this is probably fine. If using it to attack someone/something with magic resistance remotely, it is probably a Bad Idea sup[/sup] to use something other than concentration...

The rules of Meta Magic (Muto Vim) suggest that you can use D:momentary to cast a single spell immediately following the casting of D:Momentary Intangible tunnel. I'm rather uncomfortable with that, but some troupes might well see this as possible...

Arcane tunnels are a whole bag of cats all on their own.

For newer players interested in serious arcane tunnel shenanigans and the kinds of tricks you can pull with them, I recommend grabbing the book Hermetic Projects - specifically the chapter about arcane tunnel shenanigans.

Meta-magic (MuVi, ReVi) is pretty complex stuff in Ars Magica, because using it effectively requires a solid understanding of how the magic system works. Of course, once you do know how the magic system works and are comfortable with twisting it into bizarre shapes, meta-magic can be quite potent.

I'd recommend the beginner away from it, though.