Fallout: New California

Originally developed under the name Project Brazil, it spent years in development before its release in 2018. The mod requires a copy of Fallout: New Vegas Ultimate Edition to run.

Set in 2260, the story takes place before the events of Fallout 2 and the original Interplay-era games. The player takes the role of the kid from Vault 18, an orphan and mutant whose decision on the final night of the Vault Ball season alters the course of the New California Republic. The plot pits the player against factions including the New California Republic under president Wendell Peterson, the New Reno Mob's Bishop Family, the remnant Shi Clans, the Enclave's Leonidas Squadron, the Super Mutant Army, and a Raider Alliance gathered at the Athens-Tec Uranium Mine off the Long I-15.

As a total conversion, it delivers new characters, voice acting, and a branching story that can carry directly into a New Vegas playthrough. It was originally distributed through Moddb, requiring a manual installation alongside other recommended mods. In July 2026 it became available on GOG, where it installs and launches for owners of Fallout: New Vegas Ultimate Edition.