An ambitious modding project that sought to recreate Fallout 3 inside Fallout 4 is shutting down over unforeseen legal issues surrounding the original game's voice acting.

"The Capital Wasteland: A Road To Liberty" project was a five-person effort to implement the base content of Fallout 3 as a mod for Fallout 4, complete with the latter game's graphical and engine improvements. In a message to supporters, though, project lead NafNaf_95 writes that the mod has been shut down after a conversation with Bethesda, in which it "became clear our planned approach would raise some serious red flags that we had unfortunately not foreseen."

That planned approach involved an audio extraction tool that would have taken the voice acting from legitimate Fallout 3 files and converted them to a form that could be used in a Fallout 4 mod. Bethesda and an outside lawyer advised the Capital Wasteland team that extracting this licensed content, which wasn't fully owned by Bethesda, would be legally questionable under copyright law and could make the modders legally liable for damages.

While other mod projects like "Fallout 4: New Vegas" are re-recording the original voice acting to get around this kind of problem, NafNaf_95 writes that replacing Fallout 3's "iconic voices" would cause the game to "[lose] some of its charm and personally I can't bring myself to replace them." Any such re-recording would also be a massive undertaking for the five-man modding team, which as it is had only completed 30 percent of the necessary world-building after eight months of work.

Though NafNaf_95 told Kotaku that "Bethesda didn’t technically shut us down," he added that the company "heavily hinted at our methods being illegal." Bethesda has been generally supportive of the modding community, though, even opening up the console versions of Fallout 4 to mods as of 2016.

"The Capital Wasteland" is far from the first modding project to shut down over legal issues. Last year, EA shut down a mod that enabled fan-run servers in old Battlefield games . And in 2015, Take Two banned a mod that allowed for alternative online playspaces in Grand Theft Auto V , saying it could be used to "facilitate piracy."