All participants receive an exclusive Memnite promo card (while supplies last). The top 8 players each receive an exclusive full-art Tempered Steel promo card. The cards are awarded to the Top 8 players even if the tournament cuts only to the top 4.
That full-art Tempered Steel looks like this:
So already we've got something worth showing up for, in addition to the baseline of "having fun playing Magic." But there's also an optional aspect to the Scars of Mirrodin Game Day, in which people can bring Miiran-affiliated and Phyrexian-affiliated decks.
What Does an "Affliated Deck" Mean?
All non-Planeswalker cards in Scars of Mirrodin are watermarked with either a Mirran or Phyrexian symbol to represent the card’s affiliation. You can build your Game Day deck to be affiliated with one of the two sides; this makes you eligible to win the Mirrodin Besieged preview cards. (Having an affiliated deck is not required for Game Day; you can play any Standard-legal deck you choose.)
An affiliated deck must have at least ten watermarked cards from its affiliated faction in its main deck, and no watermarked cards from the opposing faction in its main deck or sideboard. The deck must still be Standard-legal.
This might be a good time to mention that a feature has been added to Gatherer. Click on "Advanced" above the search box, then scroll down a bit:
Disclaimer: there's not really red arrows on the Gatherer page. So don't get confused when you see them! So now that there's an easy way to separate Mirran cards from Phyrexian, you are no doubt wondering exactly what's in it for you. After all, this is a totally optional aspect of Scars of Mirrodin Game Day (October 30-31). Why should you affiliate with the Mirrans or Phyrexians?
The top 2 finishers with Mirran-affiliated decks receive a Peace Strider preview card from Mirrodin Besieged, and the top 2 finishers with Phyrexia-affiliated decks receive a Pierce Strider preview card! This is in addition to any top 8 prize cards you might win for their overall event finish.
What? Cards from Mirrodin Besieged? Already? Let's see those cards!
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Oh, that's nice. And while we're here, Let's zoom in on that expansion symbol, since we didn't show it when we announced the set.
Okay, that about covers it. So, to recap: Scars of Mirrodin Game Day (October 30-31). If you choose to bring a deck affiliated with either the Mirrans or Phyrexians, you could win a promo card from Mirrodin Besieged. Everybody clear? Good!