This question is similar to this SE question which asks about how to "block all app & game invitations (once and for all)". My question is different: it asks about how to "block a particular, single game app". More details about what I'm after follow:
It's been months now that almost every single day I keep on getting annoying requests from some of my friends on Facebook to play a game called "Candy Crush Saga". At first, I thought my friends would go through their list of friends and send invitation to each one of them they wanted to play the game with explicitly, or maybe just bulk-invite them by pressiong one big button on the game's user interface. However, now I'm completely annoyed, and would like to block the game altogether. At least, due to frustration that's the way I've come to perceive things by just looking at the notifications area of Facebook's user interface.
So, my question is: What's the reality of what's going on, and how