Magic: The Gathering formats are different modes in which the Magic: The Gathering collectible card game can be played.   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.