There are no rules for what it looks like, and it likely varies by cleric, or at least by god.
|
The lack of any specific ruling on the matter (no DC or concentration check to stealth-channel, or perception DC to detect channeling) seems to leave it up to the GM to decide.
But there's nothing to say one way or another. Pathfinder seems to assume that even spells with no explicit visible manifestations, like detect magic or charm person, include some sort of discernible effects, and requires some special feat or mechanic to 'stealth-cast,' with the various bits of artwork showing runes and stuff around the hands of spellcasters who might be casting spells that don't otherwise have a visible component. Using that as precedent, it could be assumed that channeling energy is similarly visible.
As far as I can tell, checking here real quick, there's nothing spelling out how visible supernatural abilities like channel energy are.
One of the earlier Wayfinders had an article by moi on 'Thematic Channeling.' An earlier version is available on these forums, here.
It's a will save to resist so it's not something you can dodge, which would be reflex. Negative energy is usually depicted in dark shades - grey, black, purple. Aside from these I can't think of anything which describes it.
This decision is up to the GM or group consensus.
I would not necessarily assume any similarity between Su and Spell casting, the "swirling runes" are explicitly part of spell CASTING process independent of magical EFFECT. The runes and casting in general being part of what allows both AoO provoking/spellcasting disruption and Spellcraft ID'ing, none of which apply to Su. The general aim discussed in FAQ of "not wanting spellcasters to run amok un-noticed" doesn't NECESSARILY apply to Su-usage which are rarer and more limited and otherwise free from normal liabilities of spellcasting, and even conceding that design aim doesn't dictate the specific mechanical conclusion here.
I would say using official Paizo artwork is good guideline, but I can't recall off-hand any depiction of Channeling specifically. Of course if one goes with the interpretation that it has "swirling runes" like Spellcasting, then there would be nothing to distinguish it... implying one cannot ready against spellcasting exclusively to Channeling, at least not without usage of Spellcraft (which is nowhere alluded to being able to recognize and distinguish Su abilities).
IMHO, even if there is not noticeable manifestation, consensus is that using a Su ability is noticeable if only as intense concentration without knowledge exactly what is happening. Vast majority of people play with "if you Channel, everybody knows that you did and understand you are Cleric or something similar". Although even that basic level of noticeability is unclear IMHO, and ignores factors like whether or not the manifestation emits light (and is thus visible thru darkness, or not - an open question re: Spellcasting "runes" FAQ).
Other than "presentation of holy symbol" (which is often not remarkable, e.g. wielding a bow & arrows or iron hammer would qualify), it seems entirely left up to GM. Snakers' interesting ZK anectode does bring up the possibility of Deity-specific manifestations, although the vast majority of gods don't have any such specific information. The given info on ZK-specific manifestation also doesn't actually indicate anything about visible manifestation emanating from channeling Cleric, the victims who are affected could simply develop open wounds without e.g. aetheric blades shooting towards them from the Channeling Cleric. Assuming there are Deity-specific manifestations, it brings up interesting issue how are characters to supposed to know/recognize those? Presumably Know:Religion, but there is no basis to set the DC, or in case of ZK-specific channel, discern ZK-channel-induced-bleeding from a multitude of other possibilities.
That gets to broader issue with PRPG, that outside of actual spells covered by Knowledge:Arcane and Spellcraft, there is no metric or general guidance for assessing how Su or Ex class (or Feat) derived abilities are recognizable and understood. I.e. seeing a Witch cackle in action, or Barbarian Rage Power in action, or Cleric channel in action, are onlookers supposed to infer the relevant Class (and level tier, if relevant)? Many of these can be "fluffed" in different ways, so the manifestation (if one exists) could vary from one to another, making it unclear if there is any consistent manifestation to indicate the broader Su/Ex ability... i.e. If you're not familiar with ZK clerics, is there any reason to associate spontaneous bleeding with channeling or even cleric abilities?
I hit FAQ because I believe it deserves clarification from Paizo.
Actually even the basic spellcasting runes FAQ could be clarified re: scrolls and wands IMHO.
(as well as the "does it actually emit light?, or does it require ambient light to be seen" issue)