
Originally Posted by
AzzerUK
To stop wallhacks, you'd need the servers to be calculating line-of-sight of every player, and only sending to the clients data on enemies that should be visible on-screen (rather than clients receiving data of all enemies within a set radius, allowing hacks to then reveal those enemies).
To stop hacks that simply tell the server they've hit XX enemy (client-side-hit-detection, something Battlefield 3, Planetside 2, Defiance, and many other games use), the server would need to be monitoring each player's viewing angle, receiving information that the user had clicked/fired their gun, calculating what the bullet can hit, and acknowledging that hit. For every single player.