The Lord of the Rings: The Third Age is a turn-based tactics game for the Game Boy Advance. It was released in 2004 by EA Games. It should not be confused with the RPG of the same name, The Lord of the Rings: The Third Age, released at the same time for GameCube, PS2, and Xbox. Although it is much different from the console games of the same name, as it is a turn-based tactics game similar to Fire Emblem.

The game allows players to choose either the good or evil campaign. Once the player has selected the campaign, they can choose one of three commanders. The good side commanders are Aragorn, Gandalf and Elrond. The evil commanders are the Witch-king, Saruman and the Mouth of Sauron.

The campaign includes levels from all three movies, including battles only hinted at in the films such as Théodred's defeat at the Fords of Isen, the defense of one of Minas Tirith's beacons, and the Uruk-hai and wild men assaults on villages and outposts in Rohan. The scenarios must be beaten in order (Fellowship of the Ring, The Two Towers, The Return of the King).

The games levels are based mainly on the movies, however there are differences and inaccuracies. For example, at Helms Deep in the film The Two Towers, the Deeping wall was defended only by the Fellowship (Aragorn, Legolas and Gimli) and the Elven company commanded by Haldir. In the game level Helms Deep Breach however, only a small part of the breached wall is defended by Elves, with a large number of men of Rohan present as well. Other examples would be Minas Tirith (troops outside the wall in the game), Sauron Comes (Catapults in the game, which were not seen in the film) and Assault on Osgiliath (where the Gondorians lost in the film, yet need to win when you play the game). Also, there are some troop types that are not depicted, including the Warriors of Númenor (their role is taken by warriors of Gondor in the second age levels) and unarmoured Elves of Lothlórien (their part being taken by armoured Elf archers).

During some battles, you may choose 1-3 companions. Good heroes include Legolas, Gimli, Faramir, Boromir, Théoden, Éomer and Éowyn. Evil heroes include Lurtz, Sharku, Wormtongue, Grishnákh, Gorbag, Uglúk and Gothmog. In addition, each side has one more unlockable hero (Haldir for good and Shagrat for evil). Also, new missions can be unlocked such as Balin's Tomb, The Last Alliance, Sauron Comes, Gap of Rohan, The Board is Set and Outposts of Rohan {Link Cable only}.

Subcommanders are not available on most levels mostly used by the AI. On good: Captain (fair leadership points and powerful attack stats) Treebeard (high hit points and high damage, moderate leadership) and Merry & Pippin (poor attack and no range). On bad: Orc Chieftain (average attack and high range) Orc Commander (high attack and average range) Uruk-hai Commander (very high attack with no range) and Uruk-hai Lieutenant (high attack and range)and Wildman Chieftans on the last alliance mission you can play as sauron .