Historical Rules · 13 July 2013
Rule 100.6
Official source text from the 13 July 2013 Rules release
Most _Magic_ tournaments (organized play activities where players compete against other players to win prizes) have additional rules covered in the _Magic: The Gathering_ Tournament Rules (found at <Wizards.com/WPN/Events/Rules.aspx>). These rules may limit the use of some cards, including barring all cards from some older sets.