Historical Rules · 1 October 2012
Rule 100.6
Official source text from the 1 October 2012 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 www.wizards.com/wpn/Events/Rules.aspx). These rules may limit the use of some cards, including barring all cards from some older sets.