Possession is the act of a being generally supernatural in nature taking direct control of a living being's body. This is commonly portrayed in media as a ghost or other figure entering the body of a host in order to use the body for some purpose, whether it be noble or sinister. There are also historical reports of people becoming possessed by demons and similar entities, though in the modern era such events are considered the signs of mental illness. The Catholic Church is at times called upon to perform an exorcism, or ritual to drive a spirit from someone thought to be possessed. However, the Church first investigates if the cause can be chalked up to mental illness or some other natural malady before resorting to the practice.
In video games, possession is typically depicted in one of two ways; as a narrative device, or as a gameplay device. As a narrative device, a character may become possessed as part of the story without direct involvement from or interaction with the player, but it may be the player's job to remove the possessing spirit from its target host. As a gameplay device, the player character may have the ability to possess and directly take control of other characters, allowing the player to use the target's own abilities and equipment.
In the FPS title Geist, the player takes the role of John Raimi, who early on in the game has his spectral essence torn away from his body. Unable to take direct physical action himself, Raimi must instead possess other beings, including rats, dogs, and humans, in order to both solve puzzles and engage in combat. However, human targets must be put under a certain level of distress before possession is possible. Raimi can spook people he comes across by possessing key items in the environment in order to interact with them and give nearby people a fright.
In Dragon Age: Origins, the player comes across Connor, the son of Arl Eamon and Arlessa Isolde. Prior to the Warden's first meeting with Connor, the boy begins to show signs of magical affinity. Rather than allow him to be sent to the Circle as required by law, however, Isolde chooses to keep Connor's abilities a secret and hires Jowan to both train him in the magical arts and also to keep his powers hidden. However, Jowan had been sent to Redcliffe by Teyrn Loghain with the intent to poison Eamon. After Jowan succeeds in his task, Connor tries to save his father by allowing a desire demon to possess him. As a result, he is the unwitting source of the nocturnal hordes of the undead that lay siege to Redcliffe. The player can resolve this situation by either taking steps to enter the Fade in order to kill the desire demon possessing Connor, or by choosing to kill Connor instead.
In Stacking, the player takes the role of a tiny Matryoshka doll, or Russian nested doll. In order to solve the game's puzzles and proceed through the game, the player must hop inside larger dolls with the abilities required in order to clear the obstacles. This may require the player to hop inside several progressively larger dolls in sequence in order to be able to take control of the required doll.
In Chapter 18 of Kid Icarus: Uprising, the protagonist Pit has become trapped in a magic ring. As the chapter begins, the ring is found by a little girl, and when she puts it on, Pit discovers that he is now in control of her. As he heads for a nearby city under siege, the girl trips, and the ring flies off her finger. The ring is then found by a dog, whom Pit also possesses as it picks the ring up in its mouth. Upon entering the city, Pit locates Magnus and attempts to get him to put the ring on so that he can find out what's happened. However, Magnus tosses the ring aside and almost walks away until deciding at the last moment to pick the ring back up and put it on. The rest of the ground portion of the stage is played with Pit in control of Magnus.