Ok, I was thinking while I was playing counter-strike… I’m fairly sure that (counting separation from client and server) it would be possible to teleport, and or stand on ground that is not there in a multi-player source game.
So the only things required for this hack to work would be the original map, a program on the client side that sends the original map to the server (upon server check of file version), then the loading of the *fake map. For the client to interact on. The locations of the other players would be sent from the server to you, thus causing the players to show up in the fake map allowing them to be shot.
*Fake map would consist of a cube of player clip and a skybox in the very far distance allowing any map to be enclosed.
**So my question is, Are the bullet hits registered on the client, or on the server? And does the map get checked constantly for tampering?