If a card with an Astrotorium card back would be put into a zone other than the battlefield, exile, or the command zone from anywhere, instead its owner puts it into the command zone. This replacement effect may apply more than once to the same event. This is an exception to rule 614.5.
April 27, 2018 · Dominaria
rule 717.6 not present in this release
August 26, 2016 · Conspiracy: Take the Crown
If a Magic subgame (see rule 718) is restarted, the main game is unaffected. Main-game effects that refer to the winner or loser of the subgame now refer to the winner or loser of the restarted subgame.
July 22, 2016 · Eldritch Moon
A subgame can be created within a subgame. The existing subgame becomes the main game in relation to the new subgame.