The collectible card game Magic: The Gathering includes over 10,000 unique types of cards. But the backs on all those cards are exactly the same. To keep a deck’s contents secret, nothing could be changed from the original back design from 1993. So several errors introduced in that first printing are “locked in” forever. For instance:
1. There are ballpoint pen marks in the “Deckmaster” logo (itself a remnant of an abandoned naming system).