I've searched about this topic in the forum, and i've seen many discussions about summoning, but not this one.
Why did all the summons had a concentration duration ? Before looking into the book, i was pretty sure summoning (ghosts, spirits, others beings) was momentary because one you have summoned something, it's just here but it seems i'm wrong and i can't see why (except for demons, lucky ones)
Did you have an idea why summoning spells are concentration and not momentary ? And what happen after you break concentration in those spells ?
Since summoning an Airy Spirit has been explicitly stated in Realms of Power: Magic pg. 110 to only require a momentary duration, I would refer back to the Core Rulebook pg. 112, Durations:
If a spell with a momentary effect, such as healing a wound, creating a fire, or opening a pit, is cast with a longer duration, it generally sustains that effect for the duration, rather than having its effect multiple times within the duration.
In the case of a spell to summon a spirit, this would presumably mean that the spirit stays summoned for the entire duration. So it would prevent, say, the ghost that you just summoned from running away before you can cast Coerce the Spirits of the Night on it.
For example, Through The Aegis pg. 105 has a Momentary version of Summon the Airy Spirit of Earth, which explicitly states that "There is nothing to compel the spirit to stay once summoned".
I've totally missed this in RoP:M.
So far i've searched, i've found:
Incantation of summoning the dead (concentration) CoreBook p152
Summoning the spirit of anger (concentration) Societates p99
Summoning the spirit of fire (concentration) Mysteries Revised p.29
I was thinking that Summoning the spirit of fire (for example) was about summoning airy spirit of Ignem form, and i wonder why they builded that spell with concentration since RoP:M state it's not needed.
I understand the point "nothing to compel the spirit to stay" but then i wonder where the spirit could go, since airy spirits are described as spirits of earth (like Daimons are described as spirits trapped in Magic Realm).
I understand they can run away, but except if they can transport back in an instant to some other place (or realm), a summoner with Second Sight (or spell like ability) could cast a coerce spell aven without concentration duration of the summon spell.
Yeah, but i don't see why.
You could transport a human on another place without need for concentration. Because it's a material being, i suppose, but there is nothing really precise about that.
And for some spirits, like airy spirits, they are clearly defined as Earthy spirits in contrast with Daimons trapped in Magic Realm. Don't really see why they are "called back" from where they were before.
The way I see it, a summoned spirit is free to go wherever it wants once the summoning spell expires. Whether they are able to return to where they came from is a different question. But even if they can't do that they may well be able to escape the magus' reach (or his senses). It's the same for teleported humans, really, their means of escape just tend to be more limited.
I was thinking the same, but i'm not really sure how a spirit can escape sens of the magus quickly if he have something like second sight or a spell-like ability, except for running in the Magic Realm. And then, how does he do it ? Can he do it ? Even if he's at first an Earthly spirit.
I was thinking about something like "spirits are called back to their "anchors" in a similar way of ghosts" but i'm not satisfied with this idea, except for some spirits (like genii Loci) who clearly have something like that stated ("Genii Loci can't go far from the place they are like a human can't slip out of his skin")
It ask a couple of additionals questions from my players, like "can i found some spirits without summoning with things like second sight or Intellego" like airy elementals spirits who are in some raw matter, etc etc... But not the point of the concentration duration.
I think it probably varies from spirit to spirit. As you say, some are clearly bound to a specific place and probably just return there when they are released. Others may be able to travel to another realm. Others still may inhabit a rock or tree, which may make them inaccessible to second sight but possibly sill 'visible' to intellego spells.
I don't think all spirits have to behave the same. Some may require a summoning with a spell that has at least concentration duration to be useful, others may be expected to stick around for long enough that this isn't strictly necessary. I don't think that is a problem. A well prepared magus can exploit their weaknesses.
Keep in mind that spirits are intangible, so a spirit that doesn't want you to command it can just sink into the ground where you can't see it. Also, in Hedge Magic: Revised Edition the Nightwalkers have rules for instantaneous spiritual travel that might be adjusted to apply to spirits in general. Essentially, they can either travel as an incorporeal being at typical speeds, or can choose to travel instantaneously in a more magical fashion to things they know or are strongly connected to (like a True Love, the location of their Caul, or the location that they are being summoned to).
Realms of Power: The Infernal also elaborates a little bit on how summoning works, at least for demons, and it does so by creating a magical conduit and forcing the demon to travel through it in spiritual form. This lines up rather nicely with the rules Nightwalkers use.
So overall I'm inclined to say that spirits should be able to instantaneously travel to locations that are very strongly associated with them, if they are not otherwise magically obstructed, and some of them (Genius Loci for example) might actually be compelled to do so.