A player can begin to cast a spell only if a rule or effect allows that player to cast it and no rule or effect prohibits that player from casting it.
May 3, 2019 · War of the Spark
A player can’t begin to cast a spell unless a rule or effect allows that player to cast it. If that player is no longer allowed to cast that spell after completing its proposal, the casting of the spell is illegal and the game returns to the moment before the casting of that spell was proposed (see rule 721, “Handling Illegal Actions”).
January 25, 2019 · Ravnica Allegiance
A player can't begin to cast a spell unless a rule or effect allows that player to cast it. If that player is no longer allowed to cast that spell after completing its proposal, the casting of the spell is illegal and the game returns to the moment before the casting of that spell was proposed (see rule 721, "Handling Illegal Actions").
April 27, 2018 · Dominaria
A player can’t begin to cast a spell unless a rule or effect allows that player to cast it. If that player is no longer allowed to cast that spell after completing its proposal, the casting of the spell is illegal and the game returns to the moment before the casting of that spell was proposed (see rule 721, “Handling Illegal Actions”).
August 26, 2016 · Conspiracy: Take the Crown
A player can’t begin to cast a spell unless a rule or effect allows that player to cast it. If that player is no longer allowed to cast that spell after completing its proposal, the casting of the spell is illegal and the game returns to the moment before the casting of that spell was proposed (see rule 720, “Handling Illegal Actions”).
July 22, 2016 · Eldritch Moon
A player can’t begin to cast a spell unless a rule or effect allows that player to cast it. If that player is no longer allowed to cast that spell after completing its proposal, the casting of the spell is illegal and the game returns to the moment before the casting of that spell was proposed (see rule 719, “Handling Illegal Actions”).
February 1, 2014 · Born of the Gods
Some spells specify that one of their controller’s opponents does something the controller would normally do while it’s being cast, such as choose a mode or choose targets. In these cases, the opponent does so when the spell’s controller normally would do so.
September 30, 2011 · Innistrad
Some spells specify that one of their controller's opponents does something the controller would normally do while it's being cast, such as choose a mode or choose targets. In these cases, the opponent does so when the spell's controller normally would do so.
June 17, 2011 · Commander 2011
Some spells specify that one of their controller’s opponents does something the controller would
April 1, 2011 · Duel Decks: Knights vs. Dragons
Some spells specify that one of their controller's opponents does something the controller would normally do while it's being cast, such as choose a mode or choose targets. In these cases, the opponent does so when the spell's controller normally would do so.
February 4, 2011 · Mirrodin Besieged
Some spells specify that one of their controller’s opponents does something the controller would normally do while it’s being cast, such as choose a mode or choose targets. In these cases, the opponent does so when the spell’s controller normally would do so.
October 1, 2010 · Scars of Mirrodin
Some spells specify that one of their controller’s opponents does something the controller would
February 1, 2010 · Worldwake
Some spells specify that one of their controller's opponents does something the controller would normally do while it's being cast, such as choose a mode or choose targets. In these cases, the opponent does so when the spell's controller normally would do so.