I'm fairly certain of the answer but here goes.

If I host Djinn on Scheherazade I get a credit. If I then play a virus and host it on Djinn do I get a credit because it is hosted (albeit indirectly) on Scheherazade?

I would argue that Scheherazade should still provide the credit but I suspect the answer is that it does not. An official answer or rules reference would be appreciated.

The rule book does not talk about indirect hosting relationships, so none exist. You don't get the credit.

"“Hosting” is the result of placing a card, counter, or token on
top of a card, creating a relationship between the host card and
what is hosted. If a card allows other cards to be hosted on it,
those cards must be hosted on the card when they are installed,
unless a card says otherwise."

The FAQ defines hosting as above. While I agree that the rules don't discuss indirect hosting I would counter that if the physical representation is an indication of the relationship then a card stacked on top of two other cards is hosted on both of them.

"If a host is trashed or uninstalled, all cards, counters, and
tokens hosted on it are also trashed. This cannot be prevented.
If a host Corp card is derezzed, all cards, counters, and tokens
hosted on it remain hosted."

Further, since the downside to Scheherazade is that the host programs could be destroyed by destroying Scheherazade and the above still applies even to programs hosted on a Djinn hosted on a Sheherazade I fail to see why from a game balance perspective the rules should exclude subhosting.

That isn't to say that they shouldn't and there may be other card designs or reasons for ruling that subhosting doesn't qualify. And for the time being I intend to play as though subhosting doesn't qualify but I'd like an explicit ruling unless someone can point to something more substantial than "it doesn't talk about it".

A card can only be hosted in one place at a time. That IS in the rules somewhere. Ergo, a card hosted on Djinn is ONLY hosted on Djinn.

EDIT: Found the location; it's in the FAQ entry for Parasite.

Parasite cannot be hosted on Djinn. A card or counter can only be hosted in one place at a time, and Parasite has the restriction that it must be installed on a piece of ice.

Further, since the downside to Scheherazade is that the host programs could be destroyed by destroying Scheherazade and the above still applies even to programs hosted on a Djinn hosted on a Sheherazade I fail to see why from a game balance perspective the rules should exclude subhosting.

The trashing on cards hosted on Sh..de that is hosted on a Djinn has nothing to do with subhosting and everything to do with the rule that whenever a card that is hosting something is trashed all the cards that were hosted on that card are trashed as well. Since the trashing of Djinn forces the trashing of Sh..de the trashing of Sh..de forces the trashing of all the cards hosted on Sh..de. Therefore you can't use that as an excuse that the game somehow allows subhosting.

@ Commissar - It's actually in the FAQ under parasite. "in one place" doesn't necessarily exclude "on more than one card". If two cards are in the same place, such as Djinn hosted on Scheherazade then hosting a card on Djinn also appears to possibly mean it is also hosted on Scheherazade.

And yes, I'm intentionally being somewhat difficult on this point. No offense is intended.

@frybender - I'm aware of the consequential effects of the rules under both interpretations. However, my point is that the wording is not explicit. I tend to agree that the likely ruling is that subhosting doesn't exist in any form, but as I prefer the other ruling and the gray space currently exists to argue for it I'm going to do so. One interpretation of a text does not preclude the use of another interpretation in debate on the meaning of the text.

@ Commissar - It's actually in the FAQ under parasite. "in one place" doesn't necessarily exclude "on more than one card". If two cards are in the same place, such as Djinn hosted on Scheherazade then hosting a card on Djinn also appears to possibly mean it is also hosted on Scheherazade.

I disagree. 'In one place' doesn't HAVE any other meaningful interpretation in the context of the game. 'Hosting' is defined as the relationship between two cards. If a card can only be hosted 'in one place' then that means it can only have a hosted relationship with that one card.

Also, I appreciate you acknowledging that you're actively attempting to find an interpretation that fits what you want (and for not being aggressive with insisting your interpretation is correct). Mature debate is rarely seen on the internet it seems. Makes a nice change.

Let me take this from another angle. What if I host Scheherazade on Djinn? Can I then host a whole bunch of icebreakers on Scheherazade? I mean according to the likely operation of the rules yes, but I fail to see how that makes sense.

@Commissar - NP.

Let me take this from another angle. What if I host Scheherazade on Djinn? Can I then host a whole bunch of icebreakers on Scheherazade?

@Commissar - NP.

Of course you can host programs on Scheherazade while it is hosted on Djinn. But programs hosted on Scheherazade are not affected by Djinn's ability to negate MU cost.

Also, there is nothing insubstantial about something not being refered to in the rules. People tend to make up all kinds of stuff, so expecting the rule book to tell you everything you can't do is not the right approach to this or any other game.

I didn't call it insubstantial. It is however less substantial than clear and explicit text in the rules. There is something very substantial about things absent from the rulebook. Until the FAQ clarified that programs could only be hosted in one place it was somewhat reasonable to conclude you could host Parasite on both Djinn and the relevant ice. Notice, I only say somewhat, I don't think it made sense that way so I never played that way but I can understand someone thinking that way. That potential interpretation of the rules is why FAQs exist. It's why the MtG comprehensive rulebook is near 200 pages in a word document.

I can and do expect a competitive card game like Netrunner to have rules that are clear and explicit about how cards interact with one another. The rules here present a likely conclusion but as I've said repeatedly it's not explicit, and thus the question.

Further, since the downside to Scheherazade is that the host programs could be destroyed by destroying Scheherazade and the above still applies even to programs hosted on a Djinn hosted on a Sheherazade I fail to see why from a game balance perspective the rules should exclude subhosting.

The trashing on cards hosted on Sh..de that is hosted on a Djinn has nothing to do with subhosting and everything to do with the rule that whenever a card that is hosting something is trashed all the cards that were hosted on that card are trashed as well. Since the trashing of Djinn forces the trashing of Sh..de the trashing of Sh..de forces the trashing of all the cards hosted on Sh..de. Therefore you can't use that as an excuse that the game somehow allows subhosting.

the OP scenario is actually a reverse of that. Djinn is hosted on Scheherezade. The main question is if you could host somehing on Djinn (while it's hosted on Scheherezade), and the answer is no, because it's hosted on Djinn, not Scheherezade.

That said, you have the right of it as far as "subhosting." Unless they introduce a new mechanic addressing just that, don't confuse the newbies guys.