voilà les règles sur le mélange:
Shuffling must be done so that the faces of the cards cannot be seen. Regardless of the method used to shuffle, players’ decks must be sufficiently randomized. Each time players shuffle their deck, they must present their deck to their opponent for additional shuffling and/or cutting. Players may request to have a judge shuffle their cards rather than pass that duty to their opponent, this request will be honored at a judge’s discretion. By presenting their decks to their opponents, players are stating that their decks are correct, legal, and sufficiently randomized.
After decks are presented and accepted, any player who does not believe his or her opponent has made a reasonable effort to sufficiently randomize his or her deck must notify a judge. The head judge has final authority to determine whether a deck has been sufficiently randomized. The head judge also has the authority to determine if a player has used reasonable effort to randomize his or her deck. If the head judge feels that either the deck has not been sufficiently randomized or that a player has not made a reasonable effort to randomize his or her deck, the player will be subject to the appropriate provisions of the DCI Penalty Guidelines.
At REL 3 and higher events players must always shuffle their opponents’ decks at the beginning of games. The head judge can mandate the shuffling of opponents’ decks at lower RELs (1 and 2) as long as he or she announces this at the beginning of the tournament. If a shuffling effect takes place during gameplay, players may shuffle and must cut their opponents’ decks after the shuffling effect is completed.
Once players shuffle and/or cut their opponents’ decks, the cards are returned to their original owners. If the opponent has shuffled the player’s deck, that player may make one final cut.
On est de toute façon obligé de mélanger suffisament ses cartes avant de présenter son deck à l'adversaire pour que les cartes soient dans un ordre le plus aléatoire possible (en sachant que c'est impossible techniquement que l'ordre soit aléatoire).
Si on présente un deck non mélangé à son adversaire, ce dernier peut appeler l'arbitre pour vérification.
Il faut également savoir que si on est surpris à tricher en tournois on risque la disqualification sans prix.