In the Intellego Mentem guidelines is the base effect at level 15: speak with any one human.
This one, of all the InMe guidelines, strikes me as the most ambiguous. What exactly does it mean? Does it allow overcoming language barriers? And if so, how is it significantly different from the base-5 version to justify the two extra magnitudes? Does it mean telepathy? And if so how is it significantly different from simply using a much lower CrMe and InMe effect to achieve the same results?
I've never seen a spell built with the guideline before, so reverse-engineering it is tricky.
Furthermore, it's the only guideline that specifies 'human' rather than 'the target.' This just makes me more curious.
So I put it to you, the community. What do you interpret this guideline to actually mean?
I think of it as the equivalent to the InAn guideline and spells built off that. I think "human" is really "being with Intelligence."
I'm not sure the CrMe telepathic sending bypasses language barriers. You form words in the target's mind, but they're still your words and the target may not understand them.
Since the guideline does not allow you to speak with those outside the Target, I would say it's at least somewhat telepathic. It could be that you both speak your own language and then you each understand just the other's speech but not the other's language. Or it could be purely telepathic. I could see both interpretations working, though I prefer the former, which helps differentiate this from CrMe.
With InMe 5 you have enough insight into the target's mind that you can understand what the target is currently saying. With InMe 15 you gain enough insight into the target's mind to perfectly match meaning to how the other party would express it -- thus allowing you not only to understand what the other is saying, but how he would say anything you might want to say yourself. It's the same difference (and the same level difference!) that one can find between reading current surface thoughts, and managing to pick whatever knowledge you want from the other's mind.
Unlike callen, we do not interpret "speak to any one human" to mean that communication must be in some sense telepathic, and that if you have two people in front of you who speak the same language you'll be understood by only one of them. Instead, we assume that the intended meaning is "it's not as if you suddenly understand every language -- only that (or those!) of the target".
CrMe cannot overcome the language barrier if used to "create words". It can do so, if used to create ideas or emotions or memories, but the InMe approach is more subtle, and allows you to do stuff you would not be able to do with CrMe. For example, suppose maga Alice wants to communicate with bishop Bob, but neither knows his language, nor can target him with magic directly. Maybe Bob is protected by magic resistance, or maybe he is far away and Alice just wants to write a letter to him. But fortunately, Carol does know Bob's language. Then Alice can use the InMe15 guideline to divine how Carol would have said what she wants to say, and can non-magically communicate it to Bob (arguably, Alice could have just asked Carol how to say it, but in this way Carol need not even be aware her knowledge is being plundered!)