(from https://mtg.fandom.com/wiki/Horde_Magic)
Rules ParticipantsHorde Magic is divided up into two factions: The Horde (the deck that runs automatically) and The Survivors (the players).
Win conditionsDepending upon the number of players and/or the type of decks being used by The Survivors, it may be necessary to adjust some of the aspects of the game in order to set the difficulty of the game to a preferable level. The following are ways to adjust the difficulty and power level of The Horde:
A Horde Deck is a 100-card constructed deck. Sixty of the cards should be tokens, the remaining forty are regular Magic cards. Cards included in the deck should not cause the Horde to have to make choices. This excludes almost any card that targets individual objects. Cards and Tokens included in the deck should be thematic, flavorful, and/or fun as well.