You may find it annoying that friends always invite you to play games you are not interested in on Facebook. While there may not be any way of preventing all future game requests, you can stop particular games from sending you invitations.
Next time you receive a game request notification simply click the notification globe icon. Next hover your mouse over the top right corner of the undesired notification. An “x” should become visible with the caption “Turn Off” . Click on this “x” and you will be presented with an option to turn off notifications for the particular game. While this may not be the best solution it does help if you receive annoying requests for the same games over and over and you have no desire to play them.