The main protagonist named Jake Sully is a physically handicapped person living on a ruined Earth. Dense urban areas now dominate the future Earth with mechanical piping all over the place. The unfortunate inhabitants of this nightmare world subsist on generic protein meals. The monetary gap between the richest and poorest Humans is vast. Those who are wealthy enjoy fantastic lives while the impoverished masses have nothing. This Earth has a devastated ecological system where most of the world's most exotic animals no longer exist.

Jake can't utilize his legs which were damaged in a past war. Jake is given the exciting prospect of going to a distant planet called Pandora around Alpha Centauri if Jake agrees to the terms of the corporate executives, who will support Jake on Pandora. It turns out that Jake's deceased brother was part of a program to make communications with the local population of Pandora called the Na’vi. It's difficult to contact the Na'vi because they are primitive and backwards, who don't particularly want to communicate with the Human extraterrestrials.

The mammoth corporation has found a means to make Human / Na'vi hybrids. The Human controller has psychokinesis control over the hybrid creature. In essence, the hybrid creature is the avatar of the Human controller. Jake has his own unique Hybrid, which is a stunningly blue colored alien entity. Exposition in the Avatar movie explains why commerce between Earth and Pandora is important to pursue and also explains why the corporations choose the avatars as the way to bridge the divide between Humans and Na'vi. The Humans on Pandora are greatly outnumbered by the native population of Na'vi.

The Na'vi are computer animated beings, who are extremely tall, but have thin bodies. They are blue in color and have no bones in their fingers. The complexity of Pandora will require for most of it to be digitally generated. Pandora features massive mountains floating over the planet that crash into each other in the sky. Pandora also has some other unique extraterrestrial entities such as the Manticore, that is a blending of a large cat like creature and a scorpion. The Slinger is a massive cat creature that can hurl its own head at the intended victim.

As the plot thickens, Jake uses his avatar to meet the Na'vi, who teach Jake to cherish their world. The nefarious Human leaders on Pandora order Jack to help them plunder the natural resources of Pandora, which attacks the Humans who have invaded. Jake and Grace Augustine try to convince the Human leaders to work with the Na'vi in harmony and peace. The Human leaders refuse to be kind and compassionate to the indigenous population. Eventually Jake and Grace rebel against the Human leaders and join with the Na'vi to defeat the Human imperialists. The Pandora planet helps the Na'vi, Jake and Grace defeat the Humans.