http://us.battle.net/hearthstone/en/blog/20852959/
- "Starting with the release of Hearthstone's next expansion (but applying to ALL Hearthstone card packs), every time you open a Legendary in a card pack, it will be a Legendary card from the same set that you don't already own."
- "In addition, you will never open more copies of any card in a pack than you can use in a single deck—no more opening three or more of the same common, rare, or epic card in one pack! "
- "Beginning with the release of the next expansion, you're also guaranteed to get a Legendary within your first 10 packs of a new set."
- In the video version, the game's director also notes that more people are playing the game than ever, and that they're excited to unveil the next set, presumably not all too long from now.
Code:
7 packs +2 packs = 9 packs total
15 packs +5 packs = 20 packs total
40 packs +12 packs = 52 packs total
60 packs* +18 packs = 78 packs total