Mecha'thun is a new card in the latest expansion for Hearthstone. It's deathrattle is that you win the game when it dies and you have no other cards in play, in your hand or in your deck.
What happens if both players have Mecha'thun die at the same time and both of the players have no other cards in play, in their deck or in their hand?
Best Answer
If both players have their Mecha'thun die at the same time, it will actually result in a draw.
Usually it is true that the first deathrattle minion that was played resolves first, but win conditions are not checked between deathrattles. So the game registers both players as dead once everything resolved, resulting in a draw.
Video of it happening