Truth be told, that actually might be a neat thing to do. Imagine trying to think up really scummy ways to inject advertising into games, create new forms of mtx, etc. just to patent them and sit on those patents.

I feel like it would do a bit of the Streisand effect since by patenting them you're making them known, but that could be a bit better than letting someone else figure it out and get exclusive use of that patent for years. Either way anyone checking gaming patents can learn about it, but in one situation it's used for the duration of the patent and in the other its not.