This DLC for *Fallout 4* (released 2016) integrates new content into the Commonwealth by tasking you with stopping the Mechanist's robot horde, including the Robobrain. The core gameplay addition allows you to harvest enemy robot parts to build and extensively customize your own robot companions, choosing from hundreds of mods for limbs, armor, and weapons like the lightning chain gun. This content requires the base game and focuses on enhancing the companion system with deep mechanical crafting.
The setting for this adventure involves a new conflict initiated by a mysterious figure known only as the Mechanist. This antagonist has unleashed a wave of hostile automatons across the wasteland, including the return of the devious Robobrain unit. Players are tasked with tracking down and eliminating these rogue machines.
The primary draw of this content is the ability to repurpose the defeated robotic enemies. Instead of simply scavenging standard junk materials, players can harvest specific components from these new mechanical foes. These harvested parts become the foundation for a new, deep customization system.
The central feature added is the ability to construct and extensively modify custom robot companions. This system allows for a high degree of player agency in designing their mechanical allies.
Players can mix and match various components to create unique robots. This includes selecting different limbs, armor plating, specialized abilities, and weaponry. Among the new armaments available is the lightning chain gun, offering a distinct combat option. Beyond functional modifications, players can also personalize their creations with different paint schemes and select distinct voice profiles for their new companions.
As downloadable content (DLC), this material requires ownership of the base game, Fallout 4, to access; it is not a standalone experience. While it introduces a substantial new system—the robot crafting mechanic—and new enemy types, its scope is focused primarily on enhancing the companion system and adding specific questlines related to the Mechanist, rather than introducing a completely new geographical area comparable in size to the main game's map. It serves as a significant enhancement to the existing Role-playing (RPG) and Shooter mechanics.