The first game in the Fallout franchise was released 20 years ago, and publisher Bethesda is celebrating the momentous event by making the game available for free on Steam.

"Fallout" was made available for free on Sept. 30, which is the exact date that the game was released in 1997. The deal was a one-day Steam-exclusive special, and the game's price has since went back to the regular $20.

Unfortunately, none of the other games in the popular franchise got special discounts for the anniversary. Still, it was a great opportunity to introduce a new generation of gamers to the roots of one of today's most notable franchises for free.

Over the years, Bethesda has implemented many improvements and changes to the "Fallout" games. However, "Fallout" is still recognized today as a very solid foundation to build the franchise on. The game introduced players to the post-apocalyptic setting and its protagonist, known as Vault Dweller. Since its release, the series has spawned four more major releases and a few spin-off games.

Following "Fallout," "Fallout 2" was released one year later. The second game was set 80 years after the original game, and followed a descendant of the Vault Dweller.

It took 10 years before the next title was released, but "Fallout 3" introduced a lot of new elements to the game, including the free roam gameplay and real time combat. "Fallout 3" was critically acclaimed, garnering many accolades, including game of the year award.

"Fallout: New Vegas," released in 2010 was not a direct sequel to "Fallout 3," but is considered a standalone game in the franchise. The game shows a post-apocalyptic version of Las Vegas.

Finally, the latest major title, "Fallout 4" was released in 2015 and continued the story of 2008's "Fallout 3."

On Dec. 12, the franchise will be releasing "Fallout 4 VR" for HTC Vive for $59.99. This will mark the franchise' first move to adapt the new virtual reality (VR) technology.