"Fallout 4" fans will get a special treat this week as Bethesda has scheduled its first-ever expansion content, "Automatron," for a March 22 release.

The upcoming add-on expands "Fallout 4" with a new mission against the mysterious Mechanist, who unleashes a number of robots – including a Robobrain – on the Commonwealth Wastelands. The new expansion showcases customization options for players as it unlocks a feature that builds and customizes robots according to the player's preferences.

According to Bethesda, "Hunt them down and harvest their parts to build and mod your own custom robot companions. Choose from hundreds of mods; mixing limbs, armor, abilities, and weapons like the all-new lightning chain gun. Even customize their paint schemes and choose their voices!"

Meanwhile, Bethesda has updated a number of details – including a screenshot of one of the characters – about the upcoming "Automatron" DLC for "Fallout 4." There is also a new trailer released by the developer.

The "Automatron" DLC is only the first part of a three-expansion project by Bethesda for "Fallout 4" this year. After the expansion drops tomorrow, fans will need to wait for April for the next scheduled DLC, 'Wasteland Workshop." To complete the trio of new content for the latest in the post-apocalyptic franchise, "Far Harbor" is scheduled to arrive in May.

While the DLC packs will come individually, players can get them all as part of the "Fallout 4" season pass, which is now available for $50.

Meanwhile, some general details like unlocked achievements have been revealed about the "Automatron" DLC. Game Informer managed to get hold of the entire series of achievements, which showcases the rewards and achievements based on mission completions in the expansion, with titles such as "Robot Hunter" and "Mechanical Menace."