Si tu es apte à distinguer une pochette sur un lot, alors tu dois changer la pochette concernée. Si tu n'es pas en mesure de la changer, (genre parce que c'est la 6e que t'habimes sur un paquet de 80), alors tu dois changer tout le monde. (encore que, tu peux changer avec celles du side, jusque là, mais quand t'auras abimé la 21e, faudra sortir le porte-monnaie).
De manière générale il est conseillé de se pointer avec un deck "nouvellement sleevé".
Texte "officiel" :
Tournament Error — Marked Cards
Penalty
Warning
Definition
A player’s cards are marked or oriented in a way that could potentially give an advantage to that player.
Examples
A. A player has small marks on a few of his sleeves. The markings are on a Mountain, a Loxodon Hierarch, and a Lightning Helix.
B. A player without sleeves has several foil cards that stand out significantly from the rest of her deck.
Philosophy
Sleeves and cards often become worn over the course of a tournament, and, as long as the player is not attempting to take advantage of this, addressing the situation is sufficient in most cases. Note that almost all sleeves can be considered marked in some way; judges should keep this in mind when determining penalties. In cases of marked cards, educating players to shuffle their cards and sleeves before sleeving the cards is very important.
Additional Remedy
The player needs to replace the card(s) or sleeve(s) with an unmarked version or, if no sleeves are being used, use sleeves that conceal the markings. If the cards themselves have become marked through play in the tournament, the Head Judge may decide to issue a proxy. If the player is unable to find replacement cards, he or she may replace those cards with basic lands for the remainder of the tournament. If he or she chooses to do so, the decklist should be changed and cannot be reverted, even if replacements are found.
The Head Judge has the option to upgrade this penalty to a Game Loss if he or she believes that a player noticing the pattern of markings would clearly compromise the integrity of the game.
Edit : attention, car si un arbitre choppe quelqu'un avec des cartes/sleeves intentionnellement marquées, alors il applique Cheating — Fraud, et c'est DQ. Just for sayin''