Black Mesa is the fan-made reimagining of Valve Software’s Half-Life.

Update 1.5 brings together all the improvements to graphics and gameplay across 15 years of development to create the final version of Black Mesa. There has never been a better time to pick up the crowbar and play!

You are Gordon Freeman, a theoretical physicist at the Black Mesa Research Facility. When a routine experiment goes horribly wrong, you must fight your way through an interdimensional alien invasion, and a bloodthirsty military clean-up crew in order to save the science team... and the world!

• A completely reimagined and refined single player campaign, including all new and expanded Xen levels
• 19 chapters of fighting through top-secret labs, running atop harsh desert landscapes, sneaking into abandoned railways, and leaping across dimensions
• Mind-Blowing graphics and effects, never before seen on the Source Engine
• Face off against an army of classic enemies, updated with new features and engaging AI
• Wield an arsenal of military hardware, scientific prototypes, and the iconic crowbar through incredibly detailed environments
• The all-new soundtrack and voice acting create a more immersive experience than ever before
• 50 Fun and challenging achievements

Frag your friends across 10 iconic maps from the Half-Life universe, including:

• Bounce
• Gasworks
• Stalkyard
• Undertow
• Crossfire

Create your own mods, models, and maps with the Black Mesa Source SDK, then share it with the community on the Steam Workshop.

Collect the full set of trading cards, backgrounds, emoticons, and achievements! Featuring Steam Cloud, Steam Workshop, closed captions in multiple languages and full controller support.