The post-apocalyptic drama, based on the bestselling game franchise of the same title, had premiered on the streamer's platform on April 10 and received positive reviews from the critics.

"Fallout" comes "Westworld" creators Jonathan Nolan and Lisa Joy's Kilter Films. Geneva Robertson-Dworet and Graham Wagner serve as the creators, executive producers, and showrunners.

In a press release, Prime Video said that in its first four days, the series has become a hit with its global audience, ranking among the service’s top three most-watched titles ever and the most-watched season globally since "The Lord of the Rings: The Rings of Power".

“Jonah, Lisa, Geneva, and Graham have captivated the world with this ground-breaking, wild ride of a show. The bar was high for lovers of this iconic video game and so far we seem to have exceeded their expectations, while bringing in millions of new fans to the franchise,” said Jennifer Salke, head of Amazon MGM Studios.

“We’d like to thank Jonah and Lisa and our friends at Bethesda for bringing the show to us as well as Geneva and Graham for coming aboard as showrunners. We are thrilled to announce season two after only one week out and take viewers even farther into the surreal world of 'Fallout'," she added.

"Fallout" presents the story of haves and have-nots in a world in which there’s almost nothing left to have, according to he official plotline.

"Two-hundred years after the apocalypse, the gentle denizens of luxury fallout shelters are forced to return to the irradiated hellscape their ancestors left behind—and are shocked to discover an incredibly complex, gleefully weird, and highly violent universe waiting for them," the plotline read.

Actor Ella Purnell stars in the show as Lucy, an optimistic Vault-dweller whose peaceful and idealistic nature is tested when she is forced to the surface to rescue her father.

Walton Goggins plays the role of the Ghoul, a morally ambiguous bounty hunter who holds within him a 200-year history of the post-nuclear world.

"Fallout" also stars Aaron Moten, Kyle MacLachlan, Moises Arias and Sarita Choudhury in pivotal roles. It is produced by Amazon MGM Studios and Kilter Films in association with Bethesda Game Studios and Bethesda Softworks.