I moved the topic here as it is apparently not covered by official crunch. Here's the deal: a few references of "warding" objects mysteriously found their way from Dark Heresy to Deathwatch. It would be a solution to a problem in one of my upcoming missions, specifically to retrieve an Irradial Cogitator (Mark of the Xenos, p. 88) - the machine with a Daemon bound inside. Now if they get to the machine, the KT might try to destroy it, or complete the objective and get it back relatively intact. In this case I need to prevent the Daemon running amok with the tech on the way home.

I figure a warded container might do the trick, but I have a Librarian in my team, who I know will be interested in this in the long run, and I don't want to simply handwave it away.

Now the questions are these:

a) Is a SM Librarian able to prepare wards? If not alone, with whose assistance?

b) If yes, what skill and test might be relevant?

c) If not, can anyone get something like DH's Hexagrammic Wards or other psy-disturbing toys (Inquisitor's handbook, pp. 189-190) in Erioch? At what price?

At one point, sooner or later, the Librarian will roll one of those entries on the Psychic Phenomena and Perils of the Warp tables mentioning warding, and since the guy usually plays wizard-type characters, the topic will come up, I'm certain of that. And while I gladly allow creativity in the game, I do want to prevent my Kill-Team going to battle against everyone dressed as Grey Knights every single time because I let my Libby create a ward this one time.

I'm not a frequent visitor here - I'm not GM-ing long enough to contribute in a meaningful way, but allow me to tap into the collective experience of the Hive Mind

I suggest Forebidden Lore: Warding

Adding skills is pretty much never a good idea.

I think it would be cooperation between a Tech-Priest/Techmarine and a Psyker/Librarian. Tech-Priest would roll either Trade or Tech-Use to make the basic circuitry and the Librarian might roll Forbidden Lore: Warp to know what to do, followed by, hmm, Psyniscience or Psy Rating to make it happen. It should not be a quick thing, though, probably take days to weeks to do.

Or just ask a Codicier on Erioch if you can borrow a warded container and don't worry about making them?

Adding skills is pretty much never a good idea.

If a player wants it and the skill does not exist, why not?

Because this system is already bloated with skills, most of which are broad to boot. And this particular skill proposition (warding an area from the Warp) already has other skills that validly cover the concept.

I'd say there are multiple ways of warding items.

Like, there is always the way where you stumble upon a book which mentions a ritual to create such an object - but it's not one of those books that the imperium likes to see. But it might be possible for a person to perform this ritual on his own. Now that I'm thinking about it, there might also be a lot of other interesting rituals in that book

Then, there might be known and accepted rituals, but those need a lot of people and/or time to perform.

Another possibility might be to find/buy an already prepared object, but I'm not sure if you can find such things on Erioch - maybe if an Ordo Hereticus Inquisitor is around incidentally.

All-in-all I'd say a Librarian is capable of creating warded objects - but it's not that easy. Either he has to pay a price (which he wouldn't want to pay more than once or twice), or it's pretty difficult and he can't do it on his own. I think that should prevent him from going to far with it.