The card “Mathemagics” has the text: “Target player draws 2x card.”
While I was playing a Pick 2 Draft, my opponent revealed that card and added it to his hand.
At that point, I reread the card's effect. Then, when he played the card, I confirmed that he paid a cost of X=4. He then chose me as the target of the card.
At that moment, I confirmed that my library contained 22 cards. Assuming that 2 to the power of 4 meant I would draw 16 cards, I accepted the card’s effect.
Therefore, in my mind, I didn’t lose the game; I simply thought my opponent, who had accepted defeat, had played the card as the final action.
However, I ran out of cards in my library and lost the game.
Since MTG Arena doesn’t have a game replay feature, I don’t know if it was a misread on my part (regarding the number of cards in my library or the number of Xs).
Honestly, I was in a dominant position on the board and would have won that match in almost any other scenario, so I suspect it was a bug or a display error (such as the number of Xs being incorrect).
I would like you to investigate and confirm exactly what happened—whether I misread the screen and my library actually had fewer than 16 cards, or whether the X was not 4—so I can see it with my own eyes.