Black Mesa Half Life Moon Interior

v3.4.4·Updated 2026-06-04

The BIGGEST Interior mod which adds a Custom Moon + Interior based off of Black Mesa Research Facility with over 130+ tiles for room generation and full of unique mechanics!

About this mod Author’s original text

Black Mesa Half Life Custom Moon and Interior

The BIGGEST Interior mod which adds a custom moon + interior based off of Black Mesa Research facility. It has over 130+ room tiles to use for dungeon generation for Lethal Company and is full of many unique mechanics. Created by Zaggy, PureFPSZac, and Plastered_Crab.

Current Features

  • The BIGGEST Interior mod with over 130+ tiles to be used for generation leading to each playthrough being a new experience for the interior
  • Use this interior on other moons OR other interiors with this custom moon
  • Healing Stations that randomly generate on walls to heal yourself in the dungeon up to a certain number of health
  • HEV charging stations will randomly generate in the dungeon allowing you to charge items when deep in the facility
  • Wall mounted laser tripmines that explode when triggered
  • Toxic Waste barrels that randomly generate to add more parkour elements
  • Lockers that you can hide from monsters in
  • Vents you can crawl into to travel to different rooms (monsters can chase you through them too)
  • Advanced generation using DungeonPlus to allow for multiple main paths each with unique themes
  • Custom Elevator
  • Custom Apparatus Room + Custom Apparatus item
  • Fully working lights that shut down when you take the new apparatus
  • Custom doors with custom animations + sounds
  • Full custom exterior moon comes with this mod and has lots of places to explore to get to the fire exits
  • Security Surveillance system in main entrance security room lets you keep an eye on possible hostile creatures trying to sneak up on you (but watch your back to the doorway behind you)
  • Handheld TVs (with Nightvision) located in the Security Room lets you broadcast what you see to the security terminal
  • The Handheld TVs (called ZagCams) can be used as Bodycams or placed on ground as well for watching specfic doorways
  • Custom Scripts for cameras and other things
  • Interactable Light Switches in some office rooms (more to come)
  • Secret Fire Exit shortcut jump
  • Main Entrance locks after 5 minutes if power is pulled

Screenshots

Main Entrance

Resonance Cascade Chamber

Surveillance Security Room in Main Entrance (with Handheld TV Zagcams)

Wall Mounted Tripmines and Toxic Waste Barrels

HEV Healing Station

HEV Charging Station

Lockers where you can hide from Monsters in

FAQ

Q: Can monsters crawl through the vents?

A: Yes! They all can go through the ventilation ducts like any other flooring!

Q: The performance is bad sometimes without CullFactory, are you going to fix that?

A: These assets are game rips from Black Mesa so they are far more detailed than Lethal Company base assets and I have done what I can to optimize it. To help with performance I highly recommend CullFactory and PathfindingLagFix to play with this as it helps with it a lot for now.

Known issues that are being actively worked on

  • no random props per tile yet (I am saving global props for last since prop dressing over 100+ tiles will take forever lol)

Planned Features

  • Randomized Parkour elements that can show up in rooms
  • New Hazards unique to Black Mesa
  • More shortcuts for the larger tiles
  • Custom Scrap based on Half Life
  • Custom Sound FX and Ambient noises
  • Steam Vents
  • Resonance Cascade Lightning Storms
  • Alien hazards like Barnacles on ceilings and Half Life turrets and tripmine lasers
  • Emergency Doors (operatable by the ship console)
  • More room tiles >:)

Support my projects

These projects take a lot of time so it is always nice to have a way for people to support the things I work on and any money I make on this gets split with the people who helped me on it:)

Credits

  • Zaggy1024 for his amazing help with fixing huge mod breaking bugs and for helping so much with the ZagCams, Charging Stations, Healing Station, and tons of other things. This mod wouldn't be alive or as good without him.
  • PureFPSZac for helping make the config and first dll for this mod, spending countless hours redoi

Install & use Install: BepInEx plugin

  1. The archive from playbuff is the mod itself — usually a BepInEx plugin (a .dll or a plugin folder once unzipped).
  2. Recommended: use a community mod manager (such as r2modman) — pick this game, import the mod, and the manager sets up BepInEx and its dependencies for you.
  3. Manual route: install the BepInEx loader in the game folder, then drop the unzipped .dll or plugin folder into BepInEx/plugins/.
  4. Launch the game — the BepInEx console logs every plugin it loads; seeing this mod in the log means it is installed.

Mods with listed dependencies need those installed too, or they will not load. Options are usually changed in-game or in the plugin's config file.

Dependencies

Install these first, or the mod will not work:

BepInEx-BepInExPackTeamXiaolan-DawnLibAlice-DungeonGenerationPlusZaggy1024-PathfindingLibZaggy1024-PathfindingLagFixZaggy1024-SmartEnemyPathfindingfumiko-CullFactory

File & checksum

Filename
Black_Mesa_Half_Life_Moon_Interior-3.4.4.zip
File size
217.6 MiB