Format

Formats are different modes in which the Magic: The Gathering collectible card game can be played. 
==Description==
Each format provides rules for deck construction and gameplay. The tournament formats officially sanctioned by the DCI fall into two categories:
*Constructed formats, in which players may build their deck from all the available cards in the format and construct their deck prior to playing in the tournament.
*Limited formats, which involve a restricted and unknown pool of cards, usually created by opening Magic: The Gathering products. These formats require players to build their decks as part of the tournament, with time allotted for deck building. 
Besides the sanctioned formats, there are many, many casual formats.
===Legality===
Tabletop tournament legality has long been determined by the global release date. This created tension between players receiving cards during Prerelease events and not being able to play them in sanctioned events until a week later. Additionally, digital play has not ever made any distinction between when cards are available and when they're tournament legal.
Starting with Phyrexia: All Will Be One, tabletop tournament legality is therefore henceforth tied to Prerelease.
==Tournament rules==
==References==