"You can thoroughly probe and understand the contents
of the mind of the target, including his or her
immediate and long-term motives, personal strengths
and weaknesses, and other pertinent information."
How do you run this?
Does it allow the caster to ask "20 questions" of the SG, and they only get the answers to the questions they ask? I really don't want to hand the player my scenario writeup when they cast it.
The duration is instantaneous, but it seems like suddenly gaining the entire contents of someone's brain, lived experiences, and knowledge would be totally overwhelming and would take some time to categorize and understand.
Is it limited only to the topics the summary lists (motives, strength, weaknesses), or how much further do you allow "other pertinent information"?
Does it get you memories? How specific?
My fear is that something will happen later where the player says "well I would have known that because I knew everything in their mind, but you didn't tell me that detail." This is why I like "Posing the Silent Question" because it's still limited to asking a specific question.
I'm struggling with what limits can be reasonably put on this spell, as now that one of our magi learned it, it seems incredibly hard to make any sort of mystery plot.
We assume that the caster gets to know the mind of the target as if said target were a very, very close friend who confided everything to him. Obviously, some details are going to be fuzzy and others easily overlooked - so the caster may be occasionally misled. But by and large he gets to know everything in or about the target's mind of some importance to either of them.
Note that the corresponding guideline says "learn all the information you wish" (rather than "any information you wish"), and the spell has D:Inst; this suggests to me that the caster learns all the information at once, since a spell allowing one detail at a time should probably be D:Conc.
A magus who can cast this spell is certainly going to have an easier time solving mysteries, just as a magus who can cast The Seven League Stride has an easy time traveling to distant locations: However:
Many potential targets may well have magic resistance or other immunities to this spell.
Other magi are protected by the Code: casting this spell on unwilling or unknowing members of the Order, including Redcaps, and their servants, familiars etc. is a big no-no.
Gaining access to the mind to be peered is not necessarily possible or easy - think of a murder committed a century before, or a mundane who steadfastedly refuses to meet the magus' "evil eye".
the guidelines say: "Learn all the information you wish from a person’s mind", so the player who cast it, have to ask questions, which I would answer form the perspective of the victim.
Yes, crime and mystery adventures change a lot (like a crime movie, where the reader already know the culprit).
But does the victim knows enough, is his memory relieable - a drunken witness can remember easily the wrong thing?
Any rarely: did someone changed his mind, replaced informations? Is the spell cast on a demon, which can easily lie (and demon could be drawn to the mage, if he sin with being proud of his skill)? Or even if the mage know some dark secrets, can he use them - who will believe him? In a mundane situation, the mage just cant say: He is guilty, i read his mind ... so how the mage can proof it? In a hermetic situation: was mind reading allowed?
Take a look at HoH:TL p.64ff Endorsing Testimony for the expectations of Quaesitores, how memories could be tampered with. Just casting a powerful Mentem spell on a witness is just the beginning of an investigation if magic, demons or faeries are involved.
This is where the GM has to be the honest eyes and ears of the character. Ask the player what they're looking for, and just tell them everything important. Maybe call for Awareness or Folk Ken rolls to pick up details the caster thinks are important by the target doesn't. "What was in the room when you found the body?" You'll get the headline facts, but may need an Awareness roll to notice details about the footprints. "Who killed the mayor?" You'll get who they think is obvious, but roll Folk Ken to pick up on someone's unusual behaviour the target has already forgotten.
And in any case, if you're doing mysteries, the fun part often begins once you've worked out whodunnit. You may know who the murderer is, but can you prove it to someone else? What will the murderer's powerful friends do? Was the killing justified, or self-defence, and what should the PCs do about it?
Since it is instantaneous I would have the magus write down as many questions as thy want before getting answers- the feedback aspect is lost due to duration but you can still get a lot of information
If you are often designing investigations/murder-mystery adventures, and have trouble handling mind-reading spells, just ban them and be open about it.
As mentioned by @neilnjae , part of the fun is finding out who did it, but there is also the part of about proving it, was there any manipulations, magic resistance can be involved, memory altering spells can also have an impact. However, if you run a lot of investigation stories, your inspiration might run dry and you can be out of interesting ways to twist the story so it does not look too contrived, and it can become a chore after two or three of such stories.
I did ban mind-reading spell for a whole Saga: at character creation, I openly said that I was intending to do a lot of investigation stories, involving non-mage (meaning without any Parma and no protection from the Code preventing mind-reading), so I will be banning any mind-reading spells. And to be fair, I also said that mages NPC would not have access to such spell either - I left open that there might be non-hermetic ways to do mind-mind reading (it did not matter at the end). In game, the justification was that personal thoughts was in the soul area, so untouchable.
Then, the following Saga, feeling more comfortable, I allowed them as I also expanded the type of adventure and I was ready to handle such spells.
If banning seems to harsh, you can add some limitations to keep it interesting like only Range: eye work for such spell, because "Eyes are the window to the soul". Silently cast mind-reading spell cast at sight range are a lot less fun and real investigation killer. On the other hand, if you need to find a person, sit in front of him/her, then cast a spell, and probably follow that by a PeMe spell to make sure he/she does not remember requires some setup and planning, so it can be done, but it will limit the occurrence. PCs will use it once they have trimmed down the list of interesting people that can have some useful knowledge, but might be reluctant to share it. So some investigation will have already occurred, not killing within the first hour of the game all suspense and mystery.
First, a human mind is far from a perfect recording machine. Memories and beliefs can be altered, even without the help of any magic. Even a murderer could convince himself that he is innocent (or that it was "an accident"), given enough time.
In both the sagas of which I am playing the story teller, I have mentem magi with the spell and I let them use it in the following fashion : it works like a google query : you can ask for any one specific piece of information per cast of the spell. If you want to learn more, you have to cast it again (it proved sometimes a limitation when in a strong divine aura or when time is of the essence). It's not because you have an access to the whole memories of a person that you can pinpoint the exact piece of information you need in an instant, it may be as hard as finding a needle in a haystack...
Of course with multiple casts (or a longer duration) and an infinite time, you could learn everything there is to know, but I design my stories in such a way peering into the mortal mind on a single person is not the magic bullet solving everything. I find that solving the mystery is only a small part of the fun in this game anyway.
Very much what Silveroak said. The duration is instantaneous, so all questions and information to be gathered must be detailed when the spell is cast. There is no follow up or elaboration allowed (without casting the spell again).
Human memory is a tricky thing, varying greatly from person to person. Some people are not good at remembering fine details. Some people are horrible at remembering names, while others are horrible at remembering faces. Peoples beliefs also can greatly affect their memories. Eye witnesses are notoriously unreliable. It is very probable that at least some of the gained information is flat out wrong.
Also the spell does not change or improve the mind of the caster. This means that they are still limited by their own reasoning and memory capabilities when the spell ends. So even if you shoved the entire contents of of novel (which might be the amount of information they ask for), how much of it can they still effectively remember and use after the spell ends? The more information gained by the spell, the more fragmented, difficult to use, and quickly forgotten after the spell ends that information will be.
These are reasons that Concentration is more effective for this guideline. The lack of need to "decide on all information needed" before casting, the ability to ask follow up questions, the ability to ask around certain information to identify false memories.
My group plays it much like Visandus. You can get roughly one clear answer per round of duration or casting of Instantaneous.
Good point- add that there will be written responses (which are subject to the limitations of the subjects memory and perspective) and the caster will be given a short period in which to view them- while the duration is instantaneous the information gathering is magical so maybe a finesse roll and they get five seconds times their score to read the answers.
Worth noting that the Intellego Mentem guidelines say that a Momentary Mentem spell can get you the answer to one question.
Which would mean that as written Peering Into the Mortal Mind is no more useful than the lower level spell Posing the Silent Question which gives you the answer to one question.
Change Peering Into the Mortal Mind to have a longer duration, and it suddenly becomes a lot more useful.
Good catch, but I read the same text in a completely different way:
ArM5, p.149
A momentary Mentem spell can answer a single question, although it’s not necessary that the answer be expressible in a brief form.
This means that the concern that many expressed - there's is not enough time for the magus to assimilate the information generated by a "thorough probe of the target's mind" - is not valid.
So, I take it as evidence that one can ask "What are all the contents of the target's mind?" and get a thorough answer in a single round.
(Similarly, this means that one can use the level 20 guideline to obtain the target's memories of the last day at D:Inst).
That in itself would suggest that the interpretation is wrong - how can two guidelines 10 levels apart produce the same effect?
Finally, for what's worth, I tracked the original version of Peering into the Mortal Mind in ArM2. The initial text in the description is essentially identical. However, the description in ArM2 then goes on to say that:
The entire process takes about an hour, with half the relevant information available within ten minutes
(and indeed in ArM2 the spell's Duration is Concentration)