Say a demon has an Infernal Might 5 and he is hidden in the area.
Assuming Penetration 0, does that mean I have to roll 10+? 14+? 15+?
It goes on to say Divine creatures need to have their full resistance penetrated.
According to the rules on p. 184 penetration goes as follows:
So a roll of 10 on the previous example, minus the Ease Factor 9, + Penetration 0 = 1.
When compared to the demon's Infernal Might 5, it does not penetrate.
When compared to a divine creature with any might (other than 1) it does not penetrate either.
I always thought it ways saying, based on the note about them being really evil, that the Ease Factor is 1 to detect a demon. The difficulty with the demon, though, is the penetration. So my understanding is Perception + Sense Holiness and Unholiness + Aura Modifier + roll ≥ 1 + Infernal Might + Aura Modifier is needed to detect the demon.
I thought similar to Callen.
So say you have several people standing around a murdered corpse in a pentagram, and the character with Sense Holiness wants to work out what's happening.
If they can make Per + sense Holiness + aura modifier, then 9+ tells you the area is desecrated, 15+ could tell you if a given person was unholy (and therefore possibly might know who'd done the sacrificing), and 6+ will tell you if there's a might 5 demon in the area.
I'd guess that MR = MR is the best answer for that? The core book made a special stipulation that demons require only one point due to being, essentially, pure unholiness. Angels being purely divine, you probably only need to penetrate their MR by 1 as well (extrapolation, haven't found RAW in brief look.) That said, if the person with Sense Holiness and Unholiness is a good person who is working with the grace of God, the angel would probably reveal himself anyway, unless God did not desire it.
I think it's because all supernatural abilities need to penetrate to work against magic resistance, as given my Divine Might, and the penetration (p.184 of the corebook) is Effect Roll - Ease Factor + Penetration. Though the "you only need to beat it by 1 point" is quite confusing, as you actually only need to beat any magic resistance by 1 point to penetrate, with any supernatural ability (or spell), to anything with magic resistance... The description of the virtue seems to mean that with demons being so "extremely evil" you can forget about difficulty and just take their Might to beat with your Sense Holiness roll, and it makes sense because otherwise it's the same for them as for any other creature from any other realm...
In that case darkwing's numbers are true. But if there were also an angel with divine might 5 there, you would need a 21+ to discover it with your virtue (to exceed the base 15 plus magic resistance) if it were trying to hide its nature, or 15+ if it didn't care (which could be the case, if only because there it says that demons try to hide their nature, implying that other realm's being might not).
I have to say, this feels a bit strange, because with regard to InVi, the higher the magic effect's level, the easier it is to detect.
So a infernal might 50 Demon lord would be oozing so much evil that it should be easier to detect than an infernal might 5 crow. Though one could conversely argue that the demon lord might also have the supernatural oomph to hide it.
But as I understand it, that's only someone with True Faith who wishes to hide the fact, right? A person with Divine MR can choose to let that be detectable by someone with SHaU - and presumably would often do so, as it's a Divine power, acting as a kind of "moral person" verification.
I'm going by the sentence "Emissaries of Heaven rarely try to hide their nature". Presumably sometimes they want to do things like test the morality of a king without his court priest giving the game away.
Indeed, I think magic effects don't try to resist the power. What bothers me about SHaU is the "flatness" of the roll. I have a character with a score of 2, and it works about as well as it should. But I'm aware that if I bought it all the way up to (say) 7, it would still only detect demons with magic 5 higher than before, which is very little difference. Even at that score, an L25 demon is just about immune to the power, unless they are foolish enough to hang around in a large Divine aura.
It would certainly be much better applied to people and places, but for penetration I'd love to see a rule change that applied score x5 against the resistance. That's already the effective rule for Magic Sensitivity and Second Sight, which look at the magnitude of the effect.
There are workarounds to beat a high Magic Resistance.
You can use all the usual tricks, like Arcane Connections, to boost your penetration - just like with any other supernatural ability.
Since SHaUH is a divine ability, it can also be boosted by a group using Ceremony.
But, yeah, supernatural abilities in general have a problem getting through Magic Resistance due to the casting totals being low - which is largely intentional to make sure the Parma Magica is good protection against Hedge wizards.
If you have the Penetration ability, it should add to the penetration total of supernatural abilities as well, so that helps out a bit. And as mentioned, Arcane Connections can help really boost your Penetration, and once you have them, so will Sympathetic Connections.
Thanks for the suggestions. I hadn't realised I could add my Penetration (but I think my GM is a bit handwavy about these rolls anyway). I can see how Arcane Connections could be useful for exposing an undercover demon, though in practice we've usually been chasing, not exposing.
But I'm not so much as arguing that SHaU is weak as that it doesn't improve enough with ability, which is a little different.
In part, I'm thinking about all the stories where a holy person is effortlessly able to see through a powerful demon's disguise. But it's possible that they weren't using SHaU but getting a miracle.
It improves at the same pace as all other (non-accelerated) abilities. This can be considered slow in that you need to put a whole lot of xp into an ability before you see significant improvement, but changing that would affect the whole game system.
Some paths of Divine Ascent will give you a penetration boost, too. That can improve over time.
With a Divine Supernatural Ability you take no penalty to the roll from an Aura, but you might well get a bonus. Meanwhile, demons may well get penalties from the Aura they're in. If a Demon walks into a cathedral, you're looking at something like +24 or +30 right there. With a roll plus the Ability plus Penetration, only the most powerful demons won't be spotted quickly.
Except that Magic Sensitivity and Second Sight are explicitly compared to magnitudes. I understand the EP cost is consistent, but there's a downstream calculation that is different in different abilities.
(Edit: I'm making this sound like a bigger deal than I mean to. It's unlikely to make a practical difference in my game, or most.)
Just bear in mind Aura modifiers. I don't have the book handy right now, but if memory serves, in a dominion aura, SHaU would get +1 to check per aura level, while demons should get something like -5 per level. It stacks up fast since a dominion aura under lvl 3 is extremely rare. And if you're in an infernal aura, you should be on your guard and expecting the worst anyway. It's less efficient in a magical aura, but its still very good.
Second Sight is an unfair comparison since it explicitly does not need to penetrate Magic Resistance.
The Ease Factor for seeing through illusions with SS increases with the level of the illusion but it has a fixed EF for many other things, while SHaUH always has fixed ease factors (EF 0 for detecting demons, since they are so very easy to detect)
With Magic Sensitivity the Ease Factor does get lower to detect more powerful magic, but you still have to penetrate any MR.
Detecting a magical creature with MS will be easier than using SHaUH to detect an angel that is concealing its nature, but harder than using SHaUH to detect a demon. (Not counting Aura modifiers)