Subscribe to download
BMS Classic - Unforeseen Consequences (v2.0)

BMS Classic started out as a simple mod aiming to undo some of the changes brought to Black Mesa in 1.0 and 1.5, such as unnecessary railroading, insultingly excessive handholding, questionable balance decisions, and watered-down combat. Since then, it's evolved into an attempt to bring together the best parts of Black Mesa and Half-Life and expand upon them.

Bringing back HL1 setpieces that didn't make the cut for one reason or another, adding incentive for the player to explore and investigate off the beaten trail, trusting players to be able to think and reason their way through puzzles without force-feeding them the answer, expanding upon areas of the facility to make it feel more alive, and making the player have to think about how they fight to survive - that's what BMS Classic aims to do.

Many maps have also received an additional detail pass, making them more atmospheric and immersive by way of enhanced/reworked lighting and improved water visuals. Attempts have also been made to improve performance on some particularly troublesome maps, but given Source's limitations, there's only so much that can be done.


It depends. Other chapter mods, such as the Chapter Overhaul mods or VOX Restoration mods, aren't compatible. BMSC extensively edits many of the game's maps, so any other mods that edit maps are going to run into conflicts. Compatibility with some of these mods (namely the VOX Restoration mods and Black Mesa Character Expansion) is something I'd like to investigate further down the line.


BMSC is primarily a joint effort, between Vassago Rain and myself. Some chapters also have additional support or resources from other modders, as listed in the Contributors section.

It's important to note that BMSC is fundamentally a two-man effort. There's only so much we have the time, resources, and ability to do. As such, we've had to make decisions about what does or doesn't get added/changed. We're just two people with a love for Half-Life doing what we can here, to try and realize Black Mesa's full potential. If you have specific questions about why certain changes were made, or why things were added/removed/etc., feel free to ask.


This download is the second major update of BMSC's Unforeseen Consequences. As the critical early-game, it's been reverted to be more in-line with its v0.91 incarnation - less ammo, more enemies, a later Glock, and less railroading. You'll have to rely on your wits - and your crowbar - to survive. Who said Half-Life isn't a survival horror game?
Additionally, as the second major update, BMSC UC version 2.0 has received significant refinement work and polishing, from some more dynamic detailing/sequences to make the world feel alive, to adjusted level flow to allow the player to find their own way forward. There's also numerous aesthetic improvements, such as refined lighting, improved cubemaps over v1.0, and properly flowmapped water, a la L4D2 and onwards.
It also restores the v0.91 music track for the Akira elevator towards the end of the chapter.

A more detailed changelog can be found in the Workshop download folder - for this addon, that'll be somewhere like Steam/steamapps/workshop/content/362980/2385914023. The contents of the changelog can also be found in the pinned discussions, or on the change notes page.


bm_c1a1a - If your health is too low when you talk to Eli/Kleiner, the game will crash, due to trying to call the scientist healing behaviour. I've scripted things to make this as unavoidable as I possibly can, but I can't really fix it on my end. Thanks, CC.
bm_c1a1d - Backtracking via the vent to c1a1e may cause some strange behaviour, such as the bridge disappearing or the destruction sound to play twice. Investigating - this is purely aesthetic, though; the bridge's collision is still present.
bm_c1a1e - Saving/loading causes the swinging crates to reset to their default positions, which can cause you to get stuck on them briefly. This is an unfortunate side-effect of how the crates have been implemented - I don't think I can fix this, but investigating nonetheless. For now, if you absolutely must save while on a crate, stay away from the hook holding it up. If you get stuck on the crate itself, you can usually "wiggle" your way free.