That process is called (or depth testing). Pixels closer to the camera hide pixels farther away. The Hack: Flipping the Switch A classic OpenGL wallhack doesn't "read" the game's memory (that's a radar hack). Instead, it hooks into the OpenGL DLL file ( opengl32.dll ) that the game uses.
Because OpenGL is an open standard, intercepting its functions is (for screen recording, overlays, or ReShade). Distinguishing a wallhack from a legitimate overlay is incredibly hard without intrusive checks. The Cold Hard Truth: It Ruins the Game Understanding the tech is fascinating. Using it? That’s another story.
Specifically, it intercepts a function called glDepthRange() or modifies the glEnable(GL_DEPTH_TEST) state.
Let’s put on our developer glasses and look at how this actually worked, why OpenGL was the weak point, and why using it ruins the spirit of the game. CS 1.6 offered two primary rendering modes: Software (CPU-rendered, slow, ugly) and OpenGL (GPU-accelerated, smooth, pretty). Almost everyone serious about the game used OpenGL.
Today, CS2 uses a deferred rendering engine with server-side occlusion culling—making classic OpenGL wallhacks impossible. But the legend lives on in every "64-tick" server still running CS 1.6 in 2025.
For nearly two decades, the "wallhack" has been the most infamous cheat in the franchise. But unlike modern AI-driven cheats, the classic CS 1.6 wallhack was a beautiful piece of low-level graphics manipulation. It exploited the very engine that made the game look "3D": .
If you played Counter-Strike 1.6 in the early 2000s—or on a modern Warzone server—you’ve heard the accusation: “He’s walling.”
OpenGL works on a simple state machine principle. You tell the GPU: "Draw a player model" , and the GPU draws it. But crucially, you also tell the GPU: "Don't draw things behind this wall."