I have several questions about the use of Double-faced Cards and Checklists cards. I'd like to have an Official answer for consistency, as I have seen Judges give very different answers for the Origins planeswalkers and the release of Shadows over Innistrad will make them much more prevalent.

First, what is the appropriate penalty for a player using both DFCs and checklists in their decks? The Magic Tournament Rules (3.5) say:

If a player uses a checklist card to represent a double-faced card in his or her deck, then all of the double-faced cards in the deck must be represented by checklist cards, …

I have seen arguments for “Game Loss” (Deck/Decklist Problem) and “Nothing” (violation of the MTR without a clearly associated infraction in the IPG).

Second, the MTR (3.5) continues :

… and double-faced cards in a hidden zone are considered to not exist for purposes of determining deck legality.

Is a player allowed to have one checklist for Archangel Avacyn in their 75, and two actual Archangel Avacyns their box, e.g. one on each side?

Third, is it allowed to have extra unmarked checklists in the sideboard? It seems both useful for Limited (in order to mark sideboard cards on the fly as you add them to your deck) and very abusable (add extra copies of your bomb rare). Same question about having extra Marked cards, prepared in advance (in the same way some players come with their own presleeved lands).

Edited Florian Horn (April 4, 2016 07:05:08 PM)

Originally posted by Florian Horn:

First, what is the appropriate penalty for a player using both DFCs and checklists in their decks?

Your second quote - the rest of that first sentence - actually provides us with the answer. If a player is using any checklist cards, then double-faced cards don't exist. That means, if you have a checklist for Jace, Vryn's Prodigy but the actual Nissa, Vastwood Seer in your deck, the Nissa doesn't exist - thus, your deck is illegal (won't match the list w/o that Nissa), and it's a Game Loss.

Originally posted by Florian Horn:

Is a player allowed to have one checklist for Archangel Avacyn in their 75, and two actual Archangel Avacyns their box, e.g. one on each side?

ewwww… technically, yes, but I don't like it, not one bit. Make sure the actual Avacyns are in different sleeves than the deck. (That's true for any Double-Faced Card (DFC) when you're using checklists - has to be sleeved differently (which could mean no sleeves, for either the deck or the DFCs).

The good news is that availability of these cards is limited, and it's unlikely a player will keep two of something he only has to own one of - or, in the Jace case, EIGHT of them for his Standard deck…

Originally posted by Florian Horn:

Third, is it allowed to have extra unmarked checklists in the sideboard?

No.

d:^D