When you receive a game invite from a friend on Facebook, is that invite being sent to all their friends?

[john]

There are two possibilities, he might have either gave a "select all" something like that or may be he picked people whom to send requests to, whatever he did, you can always block requests from apps, just go to Privacy Settings > Manage Blocking > Block app invites to block invites from specific apps and to block specific apps go to Privacy Settings > Manage Blocking > Block apps. If you want to block all your apps requests then try Privacy Settings > Apps, Games, and Websites and click Turn off all apps