Stunned Marine

The Stunned Marine glitch is a glitch that works on Halo: Combat Evolved and Halo PC.

To see a Stunned Marine, you must play the Silent Cartographer on any difficulty. There is a glitch that makes Marines freeze, and you will be able go through them.

First, take a Warthog and fill it with Marines. Then, take the Warthog to the door guarded by a Zealot. Make your Marines get out of the Warthog. Trace back your steps until you get a "Loading... Done" message. Go back to where you left your Warthog and your Marines should be frozen.

A fun way to play with this glitch is to grab a Needler and a few Plasma Grenades. After freezing your Marines, you can shoot Needler rounds into them, but they will not explode. Similarly, Plasma Grenades will not detonate. After coloring your Marines with pink needles and shiny blue spheres, step back and watch the explosions. Note: The detonations may kill you.

It is probably due to how the Halo: Combat Evolved engine handles loading points and the trigger areas of loading points, where you, the player, travel to another loading point (the security center), but the Marines do not follow. When you left the loading point trigger area of the Silent Cartographer and went into the security center area, the AI got removed from the Marines in the previous trigger area to save memory. This is the most probable reason why this glitch happens.