Wizards of the Coast home page. DCI Tournament rules - Definitions of the various tournament formats, lists of banned and restricted cards, etc. Each person starts with a starter deck and a minimum of 4 booster packs. In addition, a set of booster packs are opened and sorted into 3-card bonus packs, with the identity of the cards hidden. You can add whatever basic land you choose.
Players are free to change their decks around any way they please in between matches.
In fact, they are encouraged to experiment and try out different colors and strategies. Each player may play any other league player at any time. During the first part of the season, we don't keep score, but the loser of each match is allowed to take 1 bonus pack to add to their set of cards. At the end of the season, playoffs are held. Anyone can enter the playoffs for an additional small fee, which pays for the prizes.