Here's a question about diabolists that it didn't occur to me to ask before:
What if diabolists do have The Gift? Could they just learn any of the Maleficia without needing to take the prerequisite Virtues? I had a delve through The Infernal but it didn't make the issue very clear, although I guessed from what it says in other books about The Gift that this would be the case.
From what I've read in other posts it sounds as if anyone can learn an Infernal Supernatural Ability so long as that character is willing to imperil his/her immortal soul. If I understand things correctly, a Gifted Infernalist has no real advantage here except, perhaps, the option of taking Hermetic Virtues...
According to the book the gifted diabolist would be able to use infernal range/duration/target.
By the way, I would allow it to use the infernal abilities with some hermetic magic. For instance an infernal spell using hermetic range/duration/target. Maybe even mixing hermetic arts and infernal abilities.
Indeed, but diabolists who don't have the Gift are created as Mythic Companions, with 21 Virtue points of which some must be used to gain the Virtues necessary to use the Maleficia. A non-magus with The Gift, however, can learn Supernatural Abilities without having to take the pre-requisite Virtues, and I was wondering if the same rule applied to the Maleficia.
The Gift allows characters to learn Supernatural Abilities aligned with the magic realm. To learn Supernatural Abilities aligned with the infernal realm, all they need is a Warping Point from an infernal source. These are separate. Since the Maleficia are infernal Arts, having The Gift doesn't make the character able to learn any of them, but experiencing the infernal does. I suppose there could be magic powers like Hex or Summoning that are tainted by the infernal but still magical, and they would need The Gift to learn those.
Also, I don't think this has been clarified anywhere, but it could be that when you subtract the value of existing Supernatural Abilities from your study total, you don't subtract the ones aligned with a different realm. For example, a magus has opened his Gift, so studying a new magic Ability has at least a -15 penalty, but if he decides to learn the infernal Maleficia, the first one's free. I like this idea because it means magi can dramatically change their magic and their powers when they become interested in one of the other realms.
EDIT: I don't have my books here, but I looked back at this thread and it looks like it must be stated somewhere that you do subtract Supernatural Ability scores from other realms unless you are joining a new tradition. Sorry for the wild and unfounded speculation based on my fallible memory! 
As you note later, this is utterly wrong.
The Gift allows a character to learn any Supernatural Ability. These rules are blind as to what realm a Supernatural Ability is aligned to, and some Supernatural Abilities may come in several flavors. When a Gifted character tries to learn a new Supernatural Ability the Source Quality is penalized by his existing Scores in Supernatural Abilities. All Supernatural Abilities penalize the Source Quality. It doesn't matter what realm they are from. The only time that Supernatural Abilities don't penalize the Source Quality is when the character has had his Gift Opened by a magical tradition, which makes some set of Supernatural Abilities "Favoured", which means that they don't penalize each other.
This is not the only way to learn Supernatural Abilities, obtaining the correct Virtues somehow (such as via a Mystery Cult) is the other main way. There are apparently other ways to learn infernal Supernatural Abilities in ROP:Infernal.
That's kind of what I was thinking as I was reading the information about Damhan-Allaidh and the Damhan-Duidsan in RoP: The Infernal. It made sense to me to assume that he at least had The Gift as members of his tradition could later become Hermetic magi, so I was guessing that Gifted diabolists would have some way of opening the arts comparable to that of magi.
The issue is merely that this does not seem to have been thought of at the time of writing ROP:Infernal. Or it was thought of and discarded for some reason.
However, your idea seems entirely sensible to me. This is approach taken in Hedge Magic: Revised. The hedge traditions described there each have ways of "Opening the Gift" to their tradition. You could perhaps use the examples there as an inspiration for diabolical "Openings of the Gift".
Well, I think saying what I wrote is "utterly" wrong is disingenuous... For one thing, The Gift most emphatically does not allow a character to learn any Supernatural Ability. It's clearly stated in ROP: The Divine on page 47 that only characters with True Faith can learn Divine Supernatural Abilities, and they learn them "just as characters with The Gift learn Magical Supernatural Abilities". And ROP: Faerie also specifies this ("This works exactly like Gifted characters learning Magic Abilities") on page 116. Actually, now that I look at it, ROP: The Infernal also specifies that The Gift allows "magical" Supernatural Abilities on page 126.
Other Supernatural Abilities do penalize the Study Total whenever a character studies them to learn them, that is true. But many of them are studied by characters who do not have The Gift, and in that case they obviously don't need to "open" The Gift to learn them. And of course, there's what happens when a magus joins a divine or infernal tradition. They immediately get four favored Supernatural Abilities associated with that realm that they can learn without penalty, without having to subtract their Arts scores or any other Supernatural Abilities from them. Faerie arguably works the same way (I think it should, and I wrote it), though it isn't stated explicitly.
This is a very puzzling accusation for you to make, as it seems to me ROP: Infernal makes quite clear that the Damhadh-Duidsan are a Hermetic tradition of infernalists. All of them have The Gift and have opened the Hermetic Arts, and they also have Favored Infernal Abilities. Of course, there might also be non-Hermetic versions of them as well, who don't have The Gift but still have the favored Abilities.
It apparently seemed unclear to Aurelius? I think he was asking whether there was non-Hermetic "Opening of the Gift" for these diabolic traditions. To the best of my knowledge ROP:Infernal does not explicitly state that there are diabolic equivalents of Opening the Arts for Gifted characters. True, it might be sort of implied that something like this happens --- as you say the character "gets 4 favoured Abilties" --- but this is not explicitly described as being the same thing as "Opening the Arts". Or maybe I was misreading what he was saying.
Also, Favoured Abilities has no meaning if a character doesn't have the Gift. You cannot learn a Supernatural Ability without the Gift.
No offense intended, but this all seems to contradict the core rulebook.
The core rules aren't as clear as they should be, which is why it's clarified in later books. The Gift allows you to learn Magic-associated supernatural Abilities, True Faith for Divine, one Infernal Warping point for Infernal, and a Sympathy score for Faerie (IIRC). The Gift is neither necessary nor helpful for supernatural Abilities associated with other realms.
Hmm, perhaps we're all talking about different things then. "Opening The Gift" isn't necessary for any supernatural realm except Magic. It's possible that joining a tradition for one of the other realms has a ceremony that is like Opening The Gift (i.e. "Opening the Faith"), but you don't have to have The Gift to learn Supernatural Abilities associated with those realms, so it's not really the same. It does work exactly as you say for the Magic realm of course, but that's because only characters with The Gift can learn Magic Supernatural Abilities.
Aurelius, can you clarify what you're asking? You want to know if Gifted diabolists can learn the Hermetic Arts, or are you maybe asking about some sort of Opening ceremony that gives them all four of their Favored Abilities?
From what I read here, I would say that he is asking the later: a ceremony (it can be quite a dreadful one there!!) to open a new diabolist to all Favored Abilities, giving him a score of 0 (or 1?) in each. pretty much like hermetics, vitkir or other traditions, jut with demons and other bad guys as the protagonists 
Cheers,
Xavi
Well, as much as I want to say it's possible, I don't think Favored Abilities work like that. I don't have Hedge Magic in front of me, but I seem to recall that with hedge wizards that have Favored Abilities like elementalists, Opening The Gift just sets what their Favored Abilities are; I don't recall that it actually gives them scores in those Abilities. That's how it works for all of the other realms, at least; you join the tradition, and then you can learn those Abilities with no penalty. You don't just get scores in them. There are Mythic Companions who start with all of the tradition's Abilities, but they take them as Virtues, from which I infer that they learned them during the time represented by character creation.
Maybe Opening The Gift is a special process associated with a specific kind of magic, like Germanic magic? So, many traditions with Germanic derived magic, like Hermetics or Vitkir, can do that special seasonal thing while others haven't incorporated it and continue to use the ancient way of learning each Ability separately? It sounds like a great subject for experimentation and original research to me.
Hedge magic also has the witches open the gift and have access to all the abilities of the tradition at once.
Cheers,
Xavi
By all means. I've been thinking about creating a Diabolist NPC, one with the Gift but who never became a Hermetic magus. I've had my question about characters with the Gift and Supernatural Abilities affiliated to other realms answered comprehensively, but now I'd just like to clarify whether a Gifted character who gets an Infernal Warping point can learn the Maleficia and Goetic Arts without having to take the requisite Virtues or not. They are, after all, Major Virtues and therefore rather expensive, which doesn't matter so much for Infernally-aligned characters created as Mythic Companions with their 21 Virtue points, but it's a different story for Gifted characters and Companions.
Yes, he can. A PC shouldn't be allowed to do so at character creation, both for balance purposes and because if your character is going to voluntarily sell his soul to Satan that should be a significant play point, not backstory for kewl powers. However, in play you don't need the Virtues, although the limits from other Abilities do apply. (And they don't apply if you get the Virtue in some way; Initiation or similar.) NPCs always happen off-stage, so anything a PC could do on or offstage, an NPC can do offstage, if it suits the needs of your stories. (We do try to avoid having human NPCs be able to do things that human PCs can't, however.)
Any character who gets a Warping Point from an Infernal source can learn the Maleficia and Goetic Arts without having to take the requisite Virtues. And, as long as they belong to a tradition with favored Abilities, those Abilities do not penalize them when learning other Infernal Supernatural Abilities (and, arguably, other Supernatural Abilities from another realm, assuming the character can in fact learn them).
It's unclear whether or not a Gifted diabolist can open his Gift to a magical tradition, without having to subtract all of his infernal Ability scores from his total. Earlier in this thread, before Hedge Magic came out, I thought the answer was probably no. However, this now strikes me as a bit unfair, because it implies that you have to Open The Gift first, and then you can get Favored Abilities in another realm, but you can't do it the other way around. It would make sense, I think, that Favored Abilities don't make your Opening Total more difficult, since Hermetic Arts don't make your Favored Abilities more difficult to learn. (Of course, by that logic, I suppose it also makes sense if you can join as many as four supernatural traditions in your lifetime, one for each Realm...)
This seems to be much more than a mere clarification, because the core rule book already includes the idea that Supernatural Abilities might be aligned with other realms. Afterall, that is where the rules are for adjusting the Penetration Score of Supernatural Abilities depending on the realm they are aligned to.
The core rule book was already perfectly clear. It is the supplements that actually make the situation unclear.
Yes, Supernatural Abilities can be aligned to other realms. If you learn them through The Gift, however, you learn the Magic versions. That is what wasn't clear.