When The Grand Calcutron enters the battlefield, each player's hand becomes a program (an ordered row of revealed cards).
Players can only play the first card of their program.
If a card would be put into a player's hand from anywhere, that player reveals it and places it anywhere within their program instead.
At the beginning of each player's end step, if that player's program has fewer than five cards, they draw cards equal to the difference.
1/19/2018 In Commander games allowing silver-bordered cards, The Grand Calcutron can be your commander.
1/19/2018 When The Grand Calcutron enters the battlefield, all players take their hands and place them face up on the table. They then order them as they choose into a row, called a “program.” The only card they may cast is the first card in their program.
1/19/2018 Whenever a card would go to a player’s hand (they drew it, it got bounced, etc.) that player can put the card anywhere in their program they wish. At the beginning of each end step, if you have fewer than five cards in your program, you draw cards until you have five.
1/19/2018 Your program is still your hand. If you discard a card, it goes from your program to your graveayard.
1/19/2018 After The Grand Calcutron leaves the battlefield, players pick their cards up and put them back in their hand. They are no longer public and no longer follow the rules of The Grand Calcutron.