Steve's hotbar in the Courier's hands: Minecraft blocks, built into New Vegas.
Play Fallout: New Vegas with Minecraft running hidden alongside it, drawn right into the Mojave. Press B for build mode: Steve's hand and hotbar appear, and you place and break Minecraft blocks on New Vegas's own ground, rocks and roofs.
Press J to salvage your junk into Minecraft materials: scrap metal into stone bricks and iron, tin cans into sandstone, Wonderglue into slime balls, and 14 kinds of junk in all.
Build to unlock Courier perks: a farm sends fresh food every day, a house (bed, door and roof) gives +25 carry weight, and a lit beacon brings 100 caps a day. Finishing Goodsprings-area quests drops Fallout-themed chests next to you in Minecraft, and you start with a kit to build with.
Single player. You need Fallout: New Vegas and a Microsoft account that owns Minecraft: Java Edition. The first Play asks you to sign in once, then downloads Minecraft by itself.
Credits: built on universal-modder's Minecraft passthrough example (MIT). Bundles Prism Launcher (GPL-3.0) and Fabric API (Apache-2.0), unmodified.
