Half-Life 3 has been the source of much excitement and anticipation for many years now, despite Valve never actually having announced the game.

Well, it seems the cat is out of the bag with Valve filing a trademark for 'Half-Life 3', as it previously did with 'Half-Life' and 'Half-Life 2'.

While it's possible the company has trademarked the game simply to protect its intellectual property, a far more likely option is that it's actually working on the game.

Half-Life and its 2004 sequel Half-Life 2 are widely considered to be among the best video games of all time.