The Vault has found some information pertaining the Fallout movie planed by Interplay, and while the films itself was canceled, it did get a 15-page film treatment back in 1998.
According to the site, Interplay Films was created to develop its videogames into movies. A Fallout script was to be written by Brent V. Friedman, a quite a few studios were interested in the idea but Interplay Films was dissolved in 2000 before a deal could be inked.
The writer has passed along his film treatment which you can find through this PDF link, but The Vault has provided a small summary:
Hero at prestigious job — or so he’s told — as Assistant Vault Supervisor, working on Supply Inventory. He inspects the G.E.C.K. — The Garden of Eden Creation Kit. As part of his daily ritual as resident dreamer, he watches an old promo tape, which explains the G.E.C.K. is a miraculous, one-shot terra forming device to be used by the Vault Dwellers upon eventual emergence onto the surface. Our Hero can’t wait. Then he discovers some anomaly in the vault’s water supply. Makes presentation to Vault Supervisor (his father), who is pleased at how sharp our Hero is… but also knows how bored he is. Father’s already seen video tape of the tram incident – this is not the first time Hero has disturbed the peace. Establish internal strife between those who believe salvation/damnation is above. It’s become a generational thing, like the 60’s. Hero points out that all his generation’s complaints with pre-fab Vault life are irrelevant without water…
Written before the release of Fallout 2, the treatment linked to was the second draft, with the third version still floating around somewhere.
Friedman said that while looking over dated treatment, there are some things he “would definitely change, but there are also scenes and aspects,” of the story that he still loves.