With the release of Unstable, we're starting to get rules questions. Of course, although there's a FAQ, the actual comprehensive rules do not cover silver-bordered sets, and never will, so to some extent it is up to the players to determine how to play cards.
We should answer to the best of our abilities, using available resources if possible (the FAQ, Mark Rosewater's social media rulings, and anything else similarly "official"), and our best reasoning beyond that. That presumably means starting from the available rules, but also includes taking into account gameplay quality: a strict rules-based ruling that completely breaks the game obviously isn't helpful.
To give some background on the overarching philosophy of Un-set rules, it's useful to have a single question about Unstable and silver-bordered rules in general, covering the "it's for fun, do what you want" ideas. We sort of already have one: Should "standard errata" be applied to silver-bordered cards? asks specifically about errata, but Alex P's answer is pretty general. We might want to post a more clear version of the question, though.
But individual specific questions are totally fine too, and we don't really need to reiterate that full spiel on individual questions. It's unnecessarily repetitive, and besides, people are coming to us looking for whatever advice is available to help them have that fun game.
I think the dicey thing is there's kinda two classes of Un-card questions:
- "How does this card work?"
All of these have a clear answer based on the card text, FAQs, and a bit of "common sense" — that's a bit different from how we answer regular MTG questions using Oracle text and comp rules, but it's very consistent with how we answer a lot of non-MTG questions.
I don't think there's any real ambiguity here.
- "How does this card work in a combo with some other non-Un-card?"
These get dicier because the truest — but least useful! — answer is essentially "It was never designed to work in all cases." You can still try to answer it, and probably come up with something that'll work fine, but there's an inherently tension there because you're taking this other card that works in black-border detail-oriented they-have-a-full-time-employee-for-this you-can-get-a-certification-letter-saying-you-know-the-right-answer-to-this world and dragging it into the pretend-you're-twelve-and-don't-have-the-Internet-to-help-you world of the Un-cards.
I think you can still answer these questions, but it would pay to have a little Ur-question or tag wiki or something you can link to that just says "Hey, so, the way Un-cards exist outside of the proper comp rules of Magic means that they can produce wholly contradictory or nonsensical situations when you introduce them to all the corner cases of individual cards, and also you should just make stuff up" after which you can give your actual answer about how you'd rule it.