Content in Tamriel Rebuilt is not a total conversion or overhaul of the game, but introduces an additional landmass, the mainland of Morrowind, which the player can freely travel to directly or by ship.

Previous Elder Scrolls titles, including Arena and Daggerfall, were set across several large, procedurally generated open-world provinces in the continent of Tamriel.

[7] From 2006 to 2009, Tamriel Rebuilt diverged to develop expanded content for The Elder Scrolls IV: Oblivion with a project to implement the province of Hammerfell into the game.

[9] In December 2009, the Tamriel Rebuilt project announced an end to its work on Hammerfell, citing a lack of manpower to create assets, which were of a higher level of quality compared to those in Morrowind.

[10] Tamriel Rebuilt has formally released eight 'expansions' for Morrowind for download, and one for Oblivion: Publications have praised the Tamriel Rebuilt project for its ambition and large scope, with some remarking that the project provided ample reason for players to revisit Morrowind,[1] and many noting the additions met or exceeded the amount of content found in the original game in terms of the size and number of locations and quests.

[24] Dr. Matthew S.S. Johnson of Southern Illinois University has written on how Tamriel Rebuilt is a unique example of community-based authorship of game-inspired texts, where the "serious dedication and participation" of the community blurs the line between the authors and audiences of video games.