|“||Overload the unit's own power source, destroying the unit but causing explosive damage similar to a grenade's.||”|
– In-Game Description, XCOM: Enemy Unknown
This ability allows a Drone to sacrifice its own health in order to deliver explosive damage. This kills the Drone on lower difficulty settings, but it may have sufficient health to survive on Classic or Impossible.
In single player, this can be used against Sectopods or Cyberdiscs with Drone escorts (or, if you hacked a lone Drone, you can use it elsewhere) if you are close enough to hack the Drones (or if you need to dispose of / damage them if the hack has almost worn off. Be careful about causing friendly fire, though). However, avoid doing so unless the soldier's Arc Thrower range was entered by a Drone and the soldier is in cover. Do not try to run up to a Sectopod or Cyberdisc with its Drones and try to facetank it unless you use Combat Stims and Titan Armor. Often, this entire strategy is undesirable over simply shooting the enemies and utilizing rechargeable / passive abilities, or grenades / rocket launchers.
In multiplayer, if the player has only a Drone left, and sacrifices it by using Overload to kill an opponent's last unit, it counts as a loss for the Drone's side.