901.15a
As an alternative option, a Planechase game may be played with just a single communal planar deck. In that case, the number of cards in the planar deck must be at least forty or at least ten times the number of players in the game, whichever is smaller. The planar deck can’t contain more phenomenon cards than twice the number of players in the game. Each card in the planar deck must have a different English name.
901.15b
In a Planechase game using the single planar deck option, the planar controller is considered to be the owner of all cards in the planar deck.
901.15c
If any rule or ability refers to a player’s planar deck, the communal planar deck is used.