Borrowed from somewhere on teh interwebs:

Andrew, Andrea, and Anders are playing Team Modern. Andrew and Anders are each playing a single Scalding Tarn. Probably a Deck/Decklist Problem, but what's the penalty and fix? IPG 3.5 says:

If the deck/sideboard and decklist both violate a maximum cards restriction (usually too many cards in a sideboard or more than four of a card), remove cards starting from the bottom of the appropriate section of the list.

So it makes sense to start “from the bottom”, with Anders's list – remove the Tarn and add a basic land of their choice if necessary. Who gets a Game Loss though? Andrew? Anders? All of the above?

(I'm going to assume this is implicitly suggesting Unified Deck Construction rules are in effect, and that you aren't simply looking for an O response; if either of these are untrue I apologize!)

My understanding is that they both get the GL - they each presented a list that violates the construction rules of the event. The fact that one of the lists won't be violating that rule once the other gets fixed doesn't change the fact that at the point of infraction they're both in violation of the other.

I don't believe that there is an “O”fficial answer to this yet, but I'm sure it's under discussion due to the upcoming Team Constructed GP at the end of the month. So, I'm going to close this while we wait for the “O”fficial answer.