EMP Medal

The EMP medal is awarded for taking out a Brute or jackle sheild with the Plasma pistol, Power Drain or a Plasma Grenade, then quickly scoring a headshot for the kill. It is only available in Halo 3 Campaign and Firefight. It is represented by a 16-sided gold star with a green orb in the middle.

The easyest may to get this medal is to have a BR or auto-mag handy to switch to after you depleate the enemies sheilds with a plasma pistol.