20 years after Half-Life 2, Half-Life 3 remains the stuff of occult whisperings: Here's every rumor we've heard about the sequel that may or may not exist

It's now been 20 years since Valve changed the world with Half-Life 2, one of the most famous shooters of all time and, two decades later, possibly the most infamous videogame cliffhanger ever. We've had a couple of episodic follow-ups since Half-Life 2 arrived on November 16, 2004, and the Half-Life: Alyx VR spinoff, but Half-Life 3 remains stubbornly elusive.

Still, hope dies hard, especially when it's fuelled by the veritable cottage industry that's grown up around watching every step Valve takes. There's been no end of leaks, rumors, and rumblings over the years, each of them assuring one and all that this time, Half-Life 3 is really happening. It never has, of course, but it's been a fun ride.