A Half-life a Quake motor egy felspécizett változatával fut.
"...Half-Life is a game being developed by Valve Software and Sierra On-Line. It is based on Quake engine with many enhancements by Valve's programmers. Changes include things like 16bit color, colored lightning, translucency, MMX support and much more detailed environments..."
A Valve a Quake I és II motort ötvözte össze a maga kiegészítéseivel.