I just thought about summoning/binding spirits in aspected (to the summoner that is) background count, and wondered whether it is a good or bad idea.
I came up with three possibilities how Aspected Background Count could affect Conjuring:

• Very Good Idea: Background Count gives the Summoner a positive Dice Pool Modifier to his Magic, but since the spirit does not share a tradition with the magician, the background count reduces the spirit's Force.
• Good Idea: ABC increases the Summoner's pool, Spirit is not affected since ABC only gives a Bonus to Magic and the Spirit uses its Force to resist.
• Bad idea: Both summoner and spirit get extra dice, but more dice for the spirit mean more drain for the summoner.

I lean most to the second option but I can't find anything supporting that spirits actually have a tradition.

I would be in the second category as well... but maybe the spirit does share the tradition... but since he is noth "completely" there while being summoned i wouldn't make it count.

I have in my games sites aspected to categories or intentions of magic as well, that allows me for example to have a site where all summonings are easier. Makes for good ressources/flavour. (For example i have a magical "club" where it is easier for all people to cast entertaining magic - everything they want to cast and used to have fun and such gets it)

Ruleswise, I'd go with the first. Spirits are not stated to have a tradition or that their tradition is the same as the summoner's, hence any tradition based Aspected Background Count should affect them. I cannot think of a situation that would result in 2. The only Aspected Background Count that (I can think of) might affect both spirit and summoner as stated in the third case is Toxic.

Conjured spirits are considered to be the same tradition as the summoner. Thus, they would not receive a Force reduction due to the background count (cannot find the rules quote at the moment, so I may be mistaken).

Aspected background count does not increase Magic, but does provide a dice pool bonus to Magical skill tests (Arcana, Assensing, Astral Combat, Banishing, Binding, Counterspelling, Enchanting, Ritual Spellcasting, Spellcasting, & Summoning) and Drain Resistance tests. Both of which apply to summoning or binding a spirit, but do not assist the spirit being summoned/bound, regardless of if it is considered "present" or not.

Would appreciate if you can find it, because I tried and came up empty.

Me too.

The only place I know of where it talks about spirit tradition is with ally spirits as they are of the same tradition as their summoner since they are also magicians.

I don't recall any edition ever stating a non-ally spirit has a tradition. I know their form varies on the summoner's tradition but has no bearing on their abilities.

The important meanings of a tradition all seem to relate to spirits.
The tradition defines what kind of spirit you can summon / bind. Okay, by itself that might not affect the spirit.
But the Tradition affects what kinds of spells the spirit can aid. Clearly, that means the spirit has to align with the tradition.
Also, the tradition determines whether the spirit is a possession or materialization spirit.
As such, it seems that summoned spirits are normally of the same tradition as the sumoner/binder. (I am sure there are exceptions, but in the normal case.)
As such, a domain aspected to the summoner should add to the force of the spirit.
Now, for summoning, it seems to me that the spirit is not present until the summoning completes, so the aspected domain won't affect the Spirits roll for resisting summoning.
But, for binding, it seems that the spirit is present. And the spirit gains force equal to the aspect. Which means the spirit gains 2*aspect dice to resist binding, while the binder only gains aspect dice to bind him. Not actually good for the magician.

i.e. The way I understand it, using an aspected domain for summoning is helpful. Using one for binding is unhelpful.
The one interesting implication is that one could use an unaspect or differently aspected domain for the binding, and it would hurt the spirit more than the mage. (A mage with Magic 6, Binding 4, trying to bind a Force 5 spirit, in an unaspected grade 3 domain would be rolling 7 dice against the spirits 4, instead of 10 to 10)

Yours,
Joel

Am aspected domain does not increase the Force of a Spirit. It adds bonus dice to magic related sill tests and drain tests (Street Magic p. 118). The Spirit does not roll a skill test to resist, whether it i present or not.

Actually, looking more closely, as far as I can tell, the text on pg 118 and 119 does not specify how an aspected domain interacts with a spirit. The mackground count section on pg 118 specifies that a normal background count subtracts from the force of the spirit. But the Aspect text simply does not talk about spirits at all.

Unfortunately, this means taht we are all stuck trying to decide the intent of the rules, since the "Written" isn't. (I had thought it was written, but it isn't.)

Yorus,
Joel