Standard format uses the two most recently-released blocks, as well as the current core set. When a new block is launched, the oldest block rotates out of the list. The following card sets are currently permitted in standard format:
- Battle for Zendikar
- Oath of the Gatewatch
- Shadows over Innistrad
- Eldritch Moon
Standard Showdown is also a constructed deck format, so the normal constructed rules apply:
•Minimum of sixty cards
•No maximum deck size, as long as you can shuffle your deck unassisted
•Up to fifteen cards in your sideboard, if used
•No more than four of any individual card in your main deck and sideboard combined (with the exception of basic lands)
Standard Showdown booster packs each contain three cards:
*One premium card from a currently legal Standard set, including Kaladesh Inventions or Zendikar Expeditions, not including double-faced cards.
*Two non-premium cards that are either a rare or a mythic rare from a set currently legal in Standard* (Battle for Zendikar up through Kaladesh).
*Cards from Oath of the Gatewatch and double-faced cards not included.
*Kaladesh Inventions and Zendikar Expeditions appear in roughly 1 in 33 boosters.
*Distributed cards will all be in English.