In the IPG under Deck/Decklist problem, it says this:

If sideboard cards are lost, make a note of this, but issue no penalty.

We had an interesting discussion about this a few days ago. Some thought it applied if you did a deckcheck for a constructed tournament and found only 14 sideboard cards with 1 missing, but others pointed out it was only a rule for incomplete limited sideboards.

EDIT: so what does it mean exactly? =)

Edited Toby Hazes (May 6, 2013 12:20:04 PM)

I believe it applies to both Constructed and Limited decklists. The
philosophy behind that being that if you lose a sideboard card, you're not
gaining an advantage. Now, that is distinctly different from not
registering the required number of cards. Obviously, that is not good. But
if I registered 15 cards in my sideboard and I'm missing a card from it,
what advantage am I gaining? I don't see one. There's also nothing with
that sentence that I can see would point it anywhere towards only applying
to Limited events.

-George FitzGerald
L2, Sarasota, FL

Follow-up question: if there is no penalty for registering a 15-card sideboard but having only a 14-card sideboard, why do we only allow sideboards of 0 or 15 cards, and not 14?

Slight shift in perspective, here: there's no penalty for a player reporting to us that they've lost a sideboard card. For a Constructed event, we should probably replace it with a basic land and update the list accordingly - but their honesty, and the fact they're telling us at a time when it can't damage the integrity of the event, are good reasons to be forgiving.

Only having a 12-card sideboard on your list allows you to claim any other 3 cards when the error is discovered - *after* having a glimpse of the metagame. Unlikely, not a good risk-reward ratio - but the potential for abuse exists.

Well I guess we'll find out how big of an issue that potential for abuse is going to be in the near future =)