Because all players play from one communal deck, the deckbuilding rules for Battle Box are less strict than they are for a format like Commander. As a consequence, most of the rules outlined below are not much more than guidelines that generally provide the best Battle Box experience. If your specific Battle Box design requires you to bend these rules, don't hesitate to do so.

Battle Box Construction
To play Battle Box, at least one of the players should bring a constructed Battle Box. Depending on how you design it, a Battle Box can be combined with many other casual formats, like Two-Headed Giant, Archenemy, Planechase or Commander. Use the starting life and other special rules of those formats in addition to the rules outlined below. If you want some sample decklists, please look at the projects on the side or bottom of each page. A Battle Box should always consist of the following:
  • A number of identical land sets. The number of land sets is up to you, but your Battle Box can't accomodate more players than the available land sets.
  • A communal deck. The deck can have any size, but a minimum of ~200 cards is recommended to ensure there's enough variety between games.
  • Any tokens you care to add.
I recommend using different colored sleeves for each of these three components to facilitate sorting out your Battle Box quickly.

The Land Sets
Each player gets a land set at the start of the game. The land sets are the same for each player, and generally consists of the following:
  • A number of basic lands, at least one of each. If you want to keep the board complexity low you can opt to only include basic lands, but be aware this also limits what cards can go in your Box - cards with heavy color requirements will not be playable.
  • Dual lands to facilitate more taxing color requirements. To keep things interesting, these dual lands should always have a drawback - I would advise tap lands such as the Coldsnap Snow Lands or the Return to Ravnica Gates. This way a player always needs to choose between the efficiency of a basic land and the versatility of a tap land. Your duals should have an equal mix of all the colors.
  • Normally, I would advise to include a total of 10 lands in each land set (10 basic lands or 5 basic lands plus 5 duals). If a Box contains particularly demanding cards, increase this total accordingly (also consider including other lands, such as Rupture Spire).

The Communal Deck
The communal deck can contain any number of cards, but there are some guidelines to consider to build a well-balanced communal deck:
  • To maximize variety between games, include only a single copy of each card in your Battle Box unless there is a really good reason to include multiples of specific cards.
  • Include approximately the same number of cards in each color. Unlike in a format like Cube where equal distribution over the different colors is crucial, a Battle Box will function fine as long as no colors are woefully over- or underrepresented.
  • Keep to a more or less flat power level. You could in principle build a Vintage Power Box or a Budget Pauper Box, but within each Box the cards should match up more or less evenly against each other. For example, a Box should not contain both a Balduvian Barbarians and an Alesha, Who Smiles at Death, because at the same mana cost their power levels are just too far apart. As a rule of thumb, keeping the power level to good uncommons and playable casual rares provides a nice Battle Box experience.
  • Don't include too much card draw. Because every card drawn from the communal deck is "live" (i.e. not a land), card draw becomes much more powerful than it usually is. It's not a problem to have some incidental card draw in your communal deck, but be aware of its power.
  • Don't include any tutors. Tutoring means a lot of time is spent searching through a complex deck, and also takes away from the variety between games. Tutoring within the first X cards (like with See the Unwritten) can be fine, but is also more powerful than it normally is.
  • Finally, don't include mana ramp or land destruction. It goes against the spirit of the format, which is built on equal availability of mana to all players, and it also eats up deck space from spells that actually do something.

Game Mechanics
Game Setup
The setup of a Battle Box game is a lot like a normal Magic game, but there are some notable exceptions:
  • Each player receives one land set. These are set aside in the Command Zone.
  • Each player takes a good chunk (~40 cards) off the communal deck to use as their personal library. Alternatively, players could draw off a central communal deck to save on kitchen table space and time spent shuffling, but be aware that this alters how cards like Crystal Ball and Hinder work; you are manipulating the top card of the library which will most likely be drawn by a different player.
  • Each player draws a starting hand of four cards from their libraries. Because lands are not part of a player's hand, starting hands need to be smaller than seven cards.
  • No mulligans are allowed. With mana separated from the rest of the cards, the need for mulligans is much less and not allowing them helps speed things along.

During the Game
Again, the Battle Box follows the standard Magic rules, with the following exceptions:
  • A player's maximum hand size is 7, not counting any lands in the Command Zone.
  • If at any time a player's library is about to run out of cards, take a new chunk off the communal deck and add it to the bottom of the player's library. A player's library can never run out of cards and the cards in each player's library are still considered to be in the communal deck.
  • Each card a player has drawn is considered owned by that player for the rest of the game or until that card is somehow put back into the communal deck.
  • Each turn, a player may put one land card from the Command Zone onto the battlefield. Treat this exactly as if the land was played from the player's hand. A player can only play one land each turn, either from their hand or their Command Zone.
  • If a card would require a player to shuffle it into his or her library, put it on the bottom of the communal deck instead. This rule accomodates the use of cards like Black Sun's Zenith without having to worry about shuffling or the exact size of each player's library.

Thoughts on Multiplayer
The Battle Box can be played with any number of players, although a Battle Box designed for dueling will probably not translate well to a five player free-for-all game and vice versa. Below are some considerations when playing with more than two players:
  • In multiplayer games, the waiting time between turns can be quite long. Consider keeping the complexity of both the land sets and the communal deck below a certain threshold to facilitate quick turns.
  • Although you can always play a free-for-all game, I would recommend checking out Two-Headed Giant or Star if you are playing with 4 or 5 players.
  • Battle Box is a format that allows for some experimentation because the entire experience is designed by one person. So, why not try something different? For example, you could have one player start his or her first turn with a Rainbow Vale in play and introduce an extra political factor to the game.