Since the last upgrade, I've bought 5 skull packs. I got a common card 3 times in a row (this shouldn't happen I think). Also, in the arena, I sometimes get stuck on some insanely overpowered deck - compared to the average level. For example, 2 of my champions are stuck in Battlegrounds against an immortal Brienne (redpointlabs) that has a level 54 werewolf. That's 300+ damage doubling every turn...
 "Magic and Empire"){kind=icon}
 "You Only Live Once"){kind=icon}