A commander may return to the command zone during a Commander game.
May 3, 2019 · War of the Spark
If a commander would be exiled from anywhere or put into its owner’s hand, graveyard, or library from anywhere, its owner may put it into the command zone instead. This replacement effect may apply more than once to the same event. This is an exception to rule 614.5.
January 25, 2019 · Ravnica Allegiance
If a commander would be exiled from anywhere or put into its owner's hand, graveyard, or library from anywhere, its owner may put it into the command zone instead. This replacement effect may apply more than once to the same event. This is an exception to rule 614.5.
January 16, 2016 · Oath of the Gatewatch
If a commander would be exiled from anywhere or put into its owner’s hand, graveyard, or library from anywhere, its owner may put it into the command zone instead. This replacement effect may apply more than once to the same event. This is an exception to rule 614.5.
February 1, 2014 · Born of the Gods
If mana would be added to a player’s mana pool of a color that isn’t in the color identity of that player’s commander, that amount of colorless mana is added to that player’s mana pool instead.
September 30, 2011 · Innistrad
If mana would be added to a player's mana pool of a color that isn't in the color identity of that player's commander, that amount of colorless mana is added to that player's mana pool instead.
June 17, 2011 · Commander 2011
If mana would be added to a player’s mana pool of a color that isn’t in the color identity of that
April 1, 2011 · Duel Decks: Knights vs. Dragons
If mana would be added to a player's mana pool of a color that isn't in the color identity of that player's commander, that amount of colorless mana is added to that player's mana pool instead.
February 4, 2011 · Mirrodin Besieged
If mana would be added to a player’s mana pool of a color that isn’t in the color identity of that player’s commander, that amount of colorless mana is added to that player’s mana pool instead.
October 1, 2010 · Scars of Mirrodin
A player may cast a general he or she owns from the command zone. Doing so costs that player
February 1, 2010 · Worldwake
A player may cast a general he or she owns from the command zone. Doing so costs that player an additional {2} for each previous time he or she cast that general from the command zone that game.