Maybe it's to explore a new world. Maybe it's to be better and stronger than before. Or maybe it's a mistake and it leaves the person Trapped in Another World.
Regardless of why, this trope involves a person who can be (or who is) downloaded into a remote interface to interact with others or another world better (or at all). This other self is otherwise an Empty Shell that does nothing. Sometimes when the remote version of himself is damaged or killed, he is hurt/killed back at home or in 'reality', but the idea is, while the main body 'sleeps', a different body acts and works remotely by his commands. This is used to play games, interact with computers, or interact with an alien world.
Unrelated to We Are Our Avatars.
- The Matrix does this with the people who plug in.
- .hack is normally about an MMO played with a head-mounted display, but players have their minds drawn into their avatars whenever the game's undocumented features kick in. That said, even when the game is operating normally, characters often act as if this trope were in effect, particularly in anime and manga stories. As the franchise progresses, the effects of being trapped in the game escalate towards nearly supernatural heights.
- The plot of Surrogates has this happen on a global scale in everyday life- everyone uses the titular robot bodies to go around, while their real bodies are kept inside their homes.
- What Yuki Nagato and the remote interfaces for the Data Thought Entity and their rival the Canopy Overmind are in Haruhi Suzumiya.
- Avatar: The titular avatars are Na'vi clone bodies that humans can remotely control to explore Pandora freely (something necessary since they can't breathe Pandora's atmosphere), as well as to earn the Na'vi people's trust and hopefully reach a diplomatic conclusion to their war. The protagonist agrees to controlling an avatar because he's paraplegic, and thus wants an avatar so he can walk again, temporary as it may be.
- Done via Astral Projection in John Carter of Mars .
- Happens a lot in Peter F. Hamilton's The Night's Dawn Trilogy. Ione Saldana and a couple of other characters download their own personalities into bio-engineered Super Soldiers to fight wars. Ione lives in a space station which she herself has never left, and the other characters are often dead. Not to mention Edenists' downloading of personality into habitat 'multiplicities', preserving their memories for centuries after their bodies are dead, or the general effect of possession. Okay, fine. The entire yarn wouldn't exist without this trope.
- Tad Willaims Otherland books are set in an AI world, so most of the main characters are avatars of assorted real life people. Orlando Gardiner, in particular, has progeria, so sometimes considers his virtual life more real than his home life. Eventually, his body dies, and he becomes a permenant inhabitant of the virtual world.
- Id_Entity is the manwha version of .//Hack, except it comes with a mode where you can actually play as you sleep, through some kind of poorly explained science babble about the subconscious mind.
- In David Weber's Safehold series, Nimue Alban's fabulously wealthy father bought her a fabulously expensive PICAa robotic body capable of temporarily hosting a human consciousness. Nimue mostly used it for extreme sports, but it was...fully functional...If You Know What I Mean. Merlin explores that aspect later, If You Know Whayou get the idea.
- This is ubiquitous in Ghost in the Shell; it's either remote interface or the person's actual brain in the avatar's body.
- Tabletop Games that explores the theme of Transhumanism usually has this as an option (sometimes the only option)for Player Character, for example some GURPS settings as well as Eclipse Phase.
- The heroes of Stargate Atlantis encounter a good Replicator living on Earth. Although she helps them she is too dangerous to remain free, so they place her in a realistic virtual world where she may live as she pleases.
- This is somewhat of a plot point in the film version of John Carter: He wasn't actually teleported to Mars, just a carbon copy controlled by his consciousness.
- Animorphs: In The Ellimist Chronicles, the Ellimist (who at that point is a Hive Mind group of Sapient Ships) downloads a copy of his personality into an Andalite body and lives among them for some time, even having a mate and children. It's implied that this may be the origins of their species' thought-speak.