The Simpsons Season 22 Episode 4 (The Simpsons s22e04) with title “Treehouse of Horror XXI” aired on Sunday, November 7th 2010 at 08:00 pm via FOX Network.
Here is summary for The Simpsons Season 22 Episode 4 :

Beware of Ouija boards, vampires and unexpected guests in the 21st annual installment of the “Treehouse of Horror.” In “War and Pieces,” the first of three spine-tingling tales, Marge, worried about the effects of excessively violent video games, encourages Bart and Milhouse to give wholesome, classic board games a shot.