The history of the Fallout games is a complicated one, but it was Bethesda's almost $6 million offer that ensured it would be the steward of the franchise, no matter what it's original creators might have hoped for.
The Fallout IP was originally owned, published, and created by Interplay, whose internal Black Isle Studios made Fallout 2. Interplay licensed the franchise to Bethesda, but hit dire financial straits in the mid-2000s and was forced to sell assets in order to pay its staff. According to Brian Fargo, co-founder of Interplay, "the only asset they really had to sell was Fallout."
Speaking to Game Informer, Fargo says that a lawsuit attached to those financial issues "made [Interplay] sell all the Fallout rights to Bethesda," but there might have been another way. Fallout's art director, Leonard Boyarsky, who had left Interplay to found Arcanum and Vampire: The Masquerade – Bloodlines studio Troika Games alongside Tim Cain and Jason Anderson said that he tried to make a bid for the rights before they got to Bethesda.
"We got some possible investment interest," Boyarsky says, "but we never even got a chance to make an offer." Bethesda reportedly paid $5.75 million to secure the rights. Previously, Cain had made clear that the three-person team of Boyarsky, Anderson, and himself had been "outbid" for the rights to make Fallout 3, but Boyarsky suggests it was a little more brutal than that. "It wouldn't have mattered if they heard our offer or not," he says, "because they would have laughed."
The rest, as they say, is history. Bethesda's held firmly onto the Fallout franchise since then, handing it off to Obsidian for New Vegas and Amazon for Fallout season 2, with Fallout 5 somewhere way off in the distance after The Elder Scrolls 6. As for Troika, two out of three of them are working as close to Fallout as you can get without being at Bethesda these days, with Tim Cain rejoining Obsidian to work on a secret project teased after The Outer Worlds 2, which Boyarsky helped build as creative director.

