Cards used in official Wizards Play Network events must be authentic Magic cards.
The use of playtest cards and proxy cards is allowed within WPN Retail Stores only for non-commercial use in unsanctioned events.
WPN Retail Stores may only allow “proxy” cards in your events as described in the current official Magic Tournament Rules. A proxy card is a card issued by a judge at an event to replace a card that has become damaged during the course of play and may only be used for the duration of that event.
A playtest card is most commonly a basic resource with the name of a different card written on it with a marker. Playtest cards are not reproductions of authentic Wizards products and are created by players for personal and non-commercial use to test deck concepts. The use of playtest cards is allowed within Retail Stores only for non-commercial use in unsanctioned events.