Most of the HUD is disabled when the screenblocks console variable is set to 12. ZDoom also offers a default fullscreen HUD, an alternate HUD, and the status bar from the original games. The SBARINFO lump can be used to define other HUDs.
The HUD also handles messages, crosshairs and the currently equipped weapon. On Windows systems, if is available, the HUD is displayed in 32-bit colors even though the game world remains in 8-bit paletted mode. (If using an OpenGL source port, the entire game is in 32-bit color, including both the HUD and the game world.)
The HUD can be configured through the HUD options menu.