Bug: Discover Mechanic
During an ixalan Premier draft game I was playing a cave deck. At a certain point in the late game i activated the blue cave's ability to discover 4. The card I had on top was a good card that costed 4 or less so I should have been able to play it. I don't remember the precise card it could have been miners guidewing but I don't remember precisely now I needed a body to block an attack and win on my next turn. But anyway, instead of being able to play that card the game counted it as if it was a land or a 5+ costed card and went ahead at exiling cards from the top of the library for the cave's discovery ability until it found a card that didn't give me a body to block my opponent, so eventually I lost sadly. Thank you for your support, I love this game and I play a lot mtga in general so I'm happy to give feedbacks when something like that happen.