Some card versions are only in foil and some are only in nonfoil
Or at least enough of a problem that in 1997, Fifth Edition came with what is now Rule 103.7a, which states In a two-player game, the player who plays first skips the draw step (see rule 504, Draw Step) of their first turn. Prior to this, player one had a strict advantage over player two, an advantage that has since been mitigated, but remains statistically observable
For example, if you have 3 life and an effect says that your life total "becomes 10," you would gain 7 life which The Wind Crystal doubles to 14, so your life total will actually become 17
Some are sophisticated enough that you might not notice the difference at a casual glance
For example, instead of "K'rrik, Son of Yawgmoth," you get "Post, Son of Rich." Incredible commitment to the bit, and isn't that what matters most in this life