To celebrate the 25th anniversary of The Elder Scrolls franchise, Bethesda is giving away the Windows PC version of The Elder Scrolls 3: Morrowind. The offer is valid through Sunday, March 31, and requires a login at Bethesda.net. Simply redeem the code “TES25TH-MORROWIND” to have the game added to your account.

The Elder Scrolls began in 1994 with The Elder Scrolls: Arena. But the series truly burst into mainstream gaming in 2002 with The Elder Scrolls 3: Morrowind. Set on the volcanic island of Vvardenfell, it introduced players to the clans of the Dunmer, a race of dark-skinned elves unique to Tamriel. It also elevated the stakes in the series, pitting players against the villainous and immortal Dagoth Ur in a fight for the future of the entire kingdom.

Morrowind would set Bethesda up for success, creating the model for its next two tremendously successful games. The Elder Scrolls 4: Oblivion and The Elder Scrolls 5: Skyrim remain two of the most popular and best-selling video games of all time.

Oddly enough, the original vision for Morrowind was much more grand than the game that eventually shipped. That’s why fans have been working for more than 17 years on Tamriel Rebuilt, which got a massive new update late last year. The game’s enduring popularity, and continued relevance, make it an essential part of our list of the best games on PC.

Bethesda is also offering a bunch of different promotions for each of its major properties, including The Elder Scrolls Online MMO and The Elder Scrolls: Legends CCG at its website.

Update (4:21 p.m. ET): Many users are experiencing issues logging in to their existing Bethesda.net account or creating a new one to take advantage of today’s promotion. Bethesda says it’s aware of the issue. Difficulties authenticating seem to have spread to The Elder Scrolls: Legends as well. You can keep tabs on server status at the official live services status page.

Update (6:23 p.m. ET): Due to increased demand and technical difficulties, Bethesda will now offer the promotion through Sunday, March 31. We’ve updated our article to reflect that.