This is a new gameplay mode I came up with, modifying the overall game a la Planechase or Archenemy. it is designed for multiplayer EDH.
Besides all the players, there is one pseudo-player. This 'player' has a spot in turn order (always last), and casts spells, but is not considered to have a library, hand, or graveyard, and is not considered a player or opponent for rules purposes. All players are considered the pseudo-player's opponents. They have three decks - an Event Deck, a Minigame Deck, and a Land Deck.
On the pseudo-player's 'turn', they put the top card of their land deck on the field. Most of these are the same basic (Plains or what have you), but roughly 20% are different (e.g. Mountain). I'll come back to that. So they put down a basic land, then reveal cards from the top of the event deck until a card is revealed whose cmc is less than or equal to the number of lands they control, then casts that card for free and puts the others on the bottom of the event deck and shuffles it. If a Mountain is revealed at the start of the turn, the deck operator reveals the top card of the minigame deck and casts that card before revealing from the event deck. At the end of the 'turn', the deck operator sacrifices all nonland permanents he or she controls (the event deck includes creatures which have ETB triggers).
This pseudoplayer cannot attack or be attacked and spells cast from the event deck or minigame deck cannot be countered or exiled.
