   Programming Role Playing Games with DirectX 2nd edition and newer DirectX api
  I got the book "Programming Role Playing Games with DirectX 2nd edition" and I notice there are things in the book that are now considered deprecated. There is a whole Section on DirectPlay. And as much as I would like to avoid this section, I am afraid it might screw up the entire engine he is trying to build. So I was just curious to know even though DirectPlay is considered deprecated by XNA, and directX10. Is it possible to use it still in DirectX 9 ??   
  I believe the libraries for directplay are separate if you just link to them you should still be able to use them, although you may want to consider not using directplay at all.Are you trying to make a multiplayer 2d roleplaying game?   ;  You can still use it but you need to be using a version of the DirectX SDK that was released before the autumn of 2007 when the headers and libraries were removed from the SDK.The Disk included with the book should contain the version of the DirectX SDK that it was compiled against if not the book will have some form of reference to the version it was compiled against.One important thing to note, you may be unable to make use of DirectPlay on Vista/Windows 7.   