Which book has the Untouchable talent/trait?

The Untouchable Background Package is in The Radical's Handbook (Dark Heresy), pg. 38.

I don't think there is anything like it in Rogue Trader, but given it's potency, I'd simply port it right over. It's rather straightforward. I'm not sure if I'm allowed to repost the whole thing in it's entirety, though.

Yes he is correct, there are no rules for taking it as a PC in RT, there are rules for it's effect on the last table in the pschic powers area however.

Thanks to both! =)

I missed the last table of the Psychic Powers chapter, but the -5 to Psy Rating seems a very powerful effect. What happens if a Psycker drops his Psy to 0 or bellow? He can't use his Powers?

Maese Mateo said:

Maese Mateo said:

Well when you consider that the lowest a psyker can use a psy power is half his psy rating (fettered) I would assume as such that he could not. Though the RAW isn't really clear on that so it'd likely be up to the GM.

It is strong yes, but consider how rare psychic blanks are to *shrug*

Even then it doesn't "always" harm the psyker, only if they're trying to manifest within 5 meters of the untouchable which isn't going to be to hard to escape unless your'e fighting in very close quarters.