The Lord of the Rings-themed MOBA (multiplayer online battle arena) game will launch on Xbox Live and PSN on December 4 in Europe.
The PS3 version will also receive an exclusive retail release and arrive a day earlier than its Xbox counterpart.
The competitive strategy title has more than 20 Guardian characters - including Gandalf and Sauron - and two maps at launch.
A number of post-release DLC packs have also been announced, adding maps, a gameplay mode and new characters, some of which appear in the Hobbit movies.
All of the game's post-release content will be available at a discounted price with a Season Pass.
Guardians of Middle-earth will be priced at £11.99 on PS3 and 1200 Microsoft Points (£10.80/$15) on Xbox 360.
Watch the debut gameplay trailer for Guardians of Middle-earth below: