Heavy Play is a grading condition of cards and other items. By definition, "Heavy Play" means:
"Card is visibly aged and played. Without a sleeve, the card will be easily identified. There may be wear through the center or artwork through the face or back of the card. Heavy white spots will be present on the black border or card back. There might be dirt along the white spots of the card or edge. The card must be played in a solid-back sleeve to be tournament worthy. The card may also have a crease, warp, or fold despite its cleanliness."