Math must be hard. I was having issues with one of the challenges and it wasn't until I looked online I realized the issue. My 2/2 was attacking a 2/1 card and would die. No idea how this makes sense... Looked up a youtube video of folks doing it and sure enough the card shouldn't die. If I'm having this issue after less than an hour, and so much frustration... We'll, it's just not worth it.