So i have just finished the latest book in the laundry files, a series that is a mix of H.P lovecraft, James bond, and the offices. One of the tools they use are warrant cards, badges that compel obedience from anyone who has sworn an oath to serve the government be they military, police officers or bureaucratic civil servants.

This got me wondering could a Rosette be used like that, could you imbue it with a reflection of the emperor's light, or some other sanction psychic power that would either compel obedience or at least put it authenticity beyond question.

I know that it's "your story" so you can put it in if you want but i was just wondering if it would be lore breaking and how far out it would be from the 40k theme.

thank you for your thoughts

Personally, I would say no -- both backgroundwise, as well as this sounds really powerful. In 40k, psychic powers generally require a sentient source to work; there aren't any scrolls or something to "save" psychic powers like magic spells in D&D.

There is such a thing as imprints, but they don't last long (various effects from sacrificial blood and ritualistic deaths) or have really weak effects ("Spook", a drug made from psyker bones).

Maybe you could sorta work around those limitations by making the Inquisitor or whoever is wielding a rosette a psyker and then use the badge as a sort of paraphernalia? By having the wielder telepathically augment its effect on a witness, anyone looking at the insignia might feel more compelled to obey. The easiest way to represent this mechanically would be to have the rosette act as a +10 or +20 bonus when the wielder is invoking a psychic power to boost their authority.

Alternatively, you could have the rosette itself be a daemonic artifact imbued with a Warp entity which, as long as it is properly subdued by its owner, could attack a witnesses' subconscious and alter their predisposition, or even command them entirely (with the caveat that the more power you "allow" the artifact to use, the more dangerous it gets, and the more likely that it will turn against you).

This is very much Radicals-only stuff, but it could make for a rather interesting device in terms of having its own plot potential, especially if a curious Acolyte inherits it from their recently deceased Inquisitor without knowing the full truth.

On a sidenote, it is also worth noting that the authenticity of a rosette can be verified without question; it's just something that not anybody could do, for it would require specialised equipment to decode its cipher.

Oh but you could totally do that, and make it a Radical Inquisitor's thing. And then send the PCs to investigate why that Inquisitor's warband have been making numerous strange requests from the planetary government/local populace recently..

On a sidenote, it is also worth noting that the authenticity of a rosette can be verified without question; it's just something that not anybody could do, for it would require specialised equipment to decode its cipher.

How would that actually work? Wouldn't anyone with the materials to verify a rosette also be able to replicate one, provided they are given enough time?

Never mind, just came up with a potential explanation while typing this post, though it doesn't sound very 40k (requiring a more organised Inquisition, easier and more reliable (though not necessarily faster) interstellar communication and a more practical attitude to technology than is usually displayed). It could work like this:

1. The Inquisition, as a whole (or on a per-sector basis), decides on an assymetric encryption algorithm.
2. Every Inquisitor chooses a stupendously long private key upon their induction, and renews it every so often.
3. Inquisitorial functionaries regularly circulate updated lists of all Inquisitors' public keys amongst the Adepta.
4. An Inquisitor who wishes to prove their identity asks the local enforcer/adept/whatever to come up with a random code and encrypt it with the Inquisitor's public key.
5. The ciphertext is then supplied to the Inquisitor's rosette, which contains a tiny cogitator with the Inquisitor's private key in its memory.
6. The rosette decodes the message and spits out the plaintext back to the enforcer, who can now be satisfied that the individual in front of them is indeed in the possession of a legitimate Inquisitor's private key.

With a number of extra precautions for security, I could see this working. Whether any institution in the 40k universe would be capable of making such a system work is of course another matter.

How would that actually work? Wouldn't anyone with the materials to verify a rosette also be able to replicate one, provided they are given enough time?

According to the Dark Heresy 2 rulebook, this is actually one possible background for your Inquisitor! I forgot the page, but I distinctively recall "fake Inquisitors" being mentioned, with one example being a Rogue Trader who simply committed himself to the cause in a vigilante fashion.

Personally, though, I would assume the verification process to be too complex and limited in deployment to allow for easy fakes. My interpretation (headcanon warning!) would be that you'd have to be taken to one of a very few major facilities, such as the Planetary Governor's palace or the Arbites Precinct-Fortress, where a large cogitator bank normally used to handle Administratum data would be able to decode, cross-reference and thus verify a rosette's cipher. Access to and the knowledge to handle this machinery alone (remember, this is 40k) would significantly limit the amount of people who would have a chance to abuse it, with most Arbites being too loyal and most Governors too afraid to even ponder the idea.

Of course, wasting an Inquisitor's time with demands for verification, insisting they accompany them to the local Arbites Precinct, would itself be a rather bad start for most people involved in an Inquisitorial investigation. This should ensure that most of the time it is sufficient to just flash your badge and have a 99,9% chance that people believe you ... unless you actually give them cause to doubt your identity, of course.

In the end, the Inquisition's name alone is feared so much that the thought of faking membership would be too terrifying for most people to contemplate -- who knows what they'll do once they catch you! Plus, the secrecy surrounding the Inquisition would probably do a lot to hide the shameful truth that, yes, you can fake a rosette. People just not knowing how easy it is could thus be a factor, too.

I guess to me the whole thing sounds like a sort of "all roads lead to Rome Terra" kind of deal, where the answer depends a lot on how you think the Inquisition operates and how prevalent advanced technology would be in one's version of the setting. Remember: there are no (or at least few) wrong ways to go about details such as these, only differences in opinion.

This being said, for the sake of completion here is the description from Black Library's Inquisition Illustrated Guide:

" Inquisitorial Rosette: Name given to an Inquisitor's official badge of office and authority, ordinarily a crimson sigil that may be further inscribed with the mark of the holder's affiliated [ordo] or the code of his issuing officio planetia. Inquisitors operating under [special condition] may choose to carry an azure variant. However, given the autonomous nature of many Inquisitors, rosettes may be personally stylised or designed. The authenticity, no matter its outward design, may be verified by the ordo coding encrypted within its structure."

On a sidenote, it is also worth noting that the authenticity of a rosette can be verified without question; it's just something that not anybody could do, for it would require specialised equipment to decode its cipher.

Indeed. Taking the one example I recall of the top of my head, an Inquisitorial agent had been arrested by planetary magistratum. The agent sent to release them had a rosette to back up the demands, and it took the 'chief of department' equivalent to be able to check it.

How would that actually work? Wouldn't anyone with the materials to verify a rosette also be able to replicate one, provided they are given enough time?

Not necessarily. If you're an organisation with a likelihood of 'need to know', you'd approach the Ordos and say "I might get a covert request for inquisitorial support. How do I determine if it's genuine?" and, if they decide you have a genuine need to know and they don't just want to fob you off (lets say you're an Arbites Judge or something) what you receive is a hand-held auspex, or a an encrypted datafile, or a servoskull, or something similar. Within its files are cross-reference codes which scan embedded codes, or check serial numbers on a numerical list, or whatever, but however it works, it's a black box that you can't see inside.

You can't get at the source data without smashing (or hacking, as appropriate) it open, and it'll delete that data if you try that.

All you know is that you got it direct from a 'genuine' inquisitor (i.e. the publicly visible Inquisitorial headquarters), and hence any rosette which pings "green" is as trustworthy as the person you got the device from. Which isn't necessarily the same as "trustworthy", of course. A particularly devious ordo in a faction fight might make considerable effort to take control of the 'front desk' responsible for sending out/maintaining/updating such things. It'd be such a shame if their rivals' rosettes all started flagging up as 'fakes' - not sustainable in the long run, as the people it'd flag the crime up to would be the ordos themselves (Impersonating an Inquisitor is a crime the Inquisition likes to deal with themselves for obvious reasons), who'd be able to verify that they were genuine - but terribly confusing and inconvenient if it were to happen en masse at a politically sensitive moment.....

Of course, wasting an Inquisitor's time with demands for verification, insisting they accompany them to the local Arbites Precinct, would itself be a rather bad start for most people involved in an Inquisitorial investigation. This should ensure that most of the time it is sufficient to just flash your badge and have a 99,9% chance that people believe you ... unless you actually give them cause to doubt your identity, of course.

Exactly. Look at it this way: Do you know what genuine FBI, Secret Service and Interpol I.D. badges look like?

If three people turn up in your shop with earpieces, very large guns, badges and detectably short tempers, demanding a fairly minor concession (access to your inventory books), are you really going to go through long-winded demands for verification?