For the Fallout: New Vegas perk of the same name, see Miss Fortune.
“Miss Fortune is a character that randomly appear in V.A.T.S. to help you out when you have the Miss Fortune perk. Just when your enemies think they have the upper hand, Miss Fortune appears to turn their world upside down.”— In game - description
Like the Mysterious Stranger, Miss Fortune will literally appear out of nowhere during V.A.T.S. to assist the Courier. However, rather than killing the enemies, Miss Fortune's attack causes little direct damage, but instead knocks them unconscious ("Fatigues" them). Her attacks hit an area and has random mishaps on people. They also have a high chance of damaging or outright breaking an enemy's weapons; this effect does apply to grenades and similar weapons and will cause them to detonate, typically killing the non-player character. After the V.A.T.S. sequences finish she will disappear as abruptly as she appeared.
pc Similar to the Mysterious Stranger, Miss Fortune may accidentally shoot one or all of your followers when she appears. This does not cause any damage to your followers directly, though it has a risk of breaking their weapons, and while knocked down they are rendered particularly vulnerable.[verified]
pc Miss Fortune can be knocked unconscious by enemies inside V.A.T.S. If this happens, V.A.T.S. will not end, and the player will continue to receive damage from enemies. [verified]
pcxbox360 If Miss Fortune appears in a certain place, like the NCR Embassy, she may appear out of V.A.T.S and, in the embassy's case, the cafeteria. She goes into 'special' dialogue with the player, but says nothing, then it exits. She can be killed, but her corpse disappears and she respawns instantly at that area. Thus, Miss Fortune's Bad Luck Bringer and the Mysterious Stranger outfit can't be looted from her corpse. [verified]