Quote Originally Posted by McBain View Post
It's x7, as Whirl said. Again, I think converting to percentages, remembering that 100% is what you get normally, makes it easier to quickly understand.

Week-long 2x = the 100% you already get +100% bonus
3x blessing = +200% bonus
4x elixir = +300% bonus

Excluding double XP events, the most bonus you can have is +600%. Since you already get 100%, your total rate of gaining XP is 700%, which is equivalent to x7.
My post came from a dev a long time back. I have no clue where to find the original post though.