Do you sometimes get double experience?

[Tregarth]

Yesterday I was killing Ratmen at level 14 and getting 28 xp per kill. Today I was killing the same Ratmen, still at level 14, and getting only 14 xp. Why the difference? Is there some game mechanic that causes you to get double experience from time to time?

[ninjacarrotx3]

The Forest of Mist probably had double exp.

Too bad I didn't know about it, or I would have been all over those ratmen & boars. xD