Thread:MagmaHound/@comment-24904069-20171213131921/@comment-25856498-20171216082555

Commons are not governed by any factors at all. It seems that whatever card that is dictated to not be any of the other rarities are common.

It makes sense that if a Legendary is obtained from a chest that does not guarantee them, it will take the place of 1 Common. Also, when extra Rares and Epics are awarded from other chests, they also do this at the expense of a common