The game is set in the world created by J. R. R. Tolkien, with optional add-on characters from the world created by H. P. Lovecraft.
The player can create a character, and choose from an extended list of races and classes, ranging from Dúnadan warriors to Elven mages. There is a lot of freedom. Actually, the game also features some things that are not found in Tolkien's books, but that do make sense in a fantasy world and add re-playability to the game.
After creating a character, the player can explore this world, gain experience and skills, defeat dangerous monsters in dark dungeons and find powerful artifacts.
There is also a multiplayer version of ToME, called TomeNET. It was formerly known as PernAngband.