To perform the "grandma glitch" in "Call of Duty: Modern Warfare 2," acquire a pistol, head towards the underpass, go to the bridge, and then make a left until you come upon a door. Use the pistol to shoot the top left corner of the door twice, the top right corner twice, the bottom left corner three times and then the bottom right hand corner four times. Finally, shoot the middle of the door several times.
After shooting the door in the proper sequence, grandma appears and briefly talks to your character before returning back through the door to retrieve a machine. When the grandma character reappears through the door, she shoots and kills your character with the machine. The grandma character continues to follow your character throughout the game, and repeatedly kills your character with the machine. This cheat code does not work in the online version of the game.
"Call of Duty: Modern Warfare 2" is a first-person shooter action video game created by Infinity Ward and released in 2009 by Activision. It is available for Xbox 360, Playstation 3 and online using Microsoft Windows. "Modern Warfare 2" is a sequel to "Call of Duty 4: Modern Warfare."