One Deck

Rules

A One Deck game works like a normal game except that every player draws from a common library and uses a common graveyard. Use the following rules when playing this variant:

If the deck runs out of cards, the game’s a draw.
The difference between a card’s controller and its owner is eliminated; if you control a card, you’re its owner, no matter who drew or played the card. For example, if you play Raise Dead, you can select any creature card from the graveyard. If you steal a creature with Ray of Command and then Unsummon that creature, the creature will go to your hand because you’re the current controller of that creature card.
To the victor go the spoils: When the player to your left is eliminated, at the end of your turn you gain control of all his or her permanents and you get the cards in his or her hand. (Discard down to the appropriate hand size if you have more cards.) It doesn’t matter who administered the final blow; at the end of the turn, the player to the eliminated player’s right gets the eliminated player’s stuff.

Deck Construction

You should build a 120-card deck for a four-player game. Add at least twenty cards for each additional player. Decks for One Deck games typically use all five colors, but you can build a deck using fewer colors if you want. Avoid using spells that require two mana of the same color in their casting cost or activation costs; that way each player will have a better chance of being able to play the cards he draws. You should also reduce the number of one- and two-mana spells. Such cards are usually good only in the early game, and it may take a while to get even one land of a particular color.

Sideboard

There is no sideboard for this variant.

Banned & Restricted List

When playing this variant it is usually decided what Type you will be playing. So, if you are playing Type 1, Type 1.5, Type 2, or Extended One Deck then, follow that format’s Banned and Restricted List.

Mulligan Rules

Standard “Paris” Mulligan is used for this variant.

Before each game begins, a player may, for any reason, reshuffle and redraw his hand, drawing one less card. This may be repeated as often as the player wishes, until he has no cards left in his hand. After the participant, who plays first, mulligans as often as he likes, the decision of whether to mulligan passes to the other player. Once a player passes the opportunity to mulligan, that player may not change his mind.