Although Avatar: The Game is named after the movie, the story itself doesn't follow the plot of the film. Instead, the player takes on the role of Lance Corporal Ryder, a signal-specialist who is sent to the distant moon Pandora. But Ryder isn't just any other soldier; they are one of the selected group of people that take part in the Avatar-program. Avatars are a hybrid of Na'vi DNA and human DNA created to better interact with the inhabitants of the planet: the Na'vi, who are tribe-like and technology-wise not very advanced, yet deeply connected to nature.
Early in the game, the player must decide whether to help the Na'vi unlock the power of the Well of Souls or stay with the humans. Depending on this choice, the gameplay changes significantly: * Human: As a human, the player can enter buildings, drive vehicles like buggies and helicopters, and use full-body armor as well as various firearms, including shotguns and flamethrowers. Pandora itself is against the player, meaning both plants and animals will attack, but also grant experience points. The player can build pods to replenish ammo and health at specific locations. * Na'vi: The Na'vi are more than two meters high and cannot enter buildings or use human vehicles. However, Pandora is friendly, so plants and animals won't attack, allowing the player to ride strange horses or fly around on huge dinosaur-like creatures. While the player can use a machine gun, the Na'vi rely on bows and arrows, strange swords, and staves. If the player achieves a five-hit combo, a special attack becomes available. The Na'vi harvest plants to get arrows and cell samples.
Both characters are controlled in a standard 3rd-person-shooter fashion and must collect DNA/cell samples. Once enough have been collected, the player gains access to the fight again after their hit-points reach zero. If not enough samples have been collected, the player respawns at the nearest outpost. Both parties earn experience points for completing quests and killing enemies. As the character levels up, they gain new weapons and spells, such as invisibility.
Pandora is divided into several sectors, each featuring challenges like lifting 100% of the fog of war or collecting a certain amount of cell samples. Fulfilling these objectives grants additional experience points. A world-domination mini-game is available at each transporter, which is turn-based and has the player starting with one sector and the goal of conquering all the others. The game offers five team-based multiplayer modes: King of the Hill, Capture the Flag, Team Deathmatch, Capture and Hold, and Final Fight.