Half-Life: Opposing Force

Released Nov 1999

Return to the Black Mesa Research Facility as one of the military specialists assigned to eliminate Gordon Freeman. Experience an entirely new episode of single player action. Meet fierce alien opponents, and experiment with new weaponry. Named 'Game of the Year' by the Academy of Interactive Arts and Sciences.

95% positive · 29K reviews

Done

All announced content has been released

High confidence

Done

All announced content has been released

High confidence

Where to buy

Steam Updated 12 Oct 2026 $4.99

Can't confirm — worth a look

We couldn't confirm these stores carry this game.

Green Man Gaming Steam key Search IndieGala Steam key Search

Prices in USD, as listed by each store.

Buying through an affiliate store helps support the site

Evaluation

Half-Life: Opposing Force is a standalone expansion to Half-Life that released on November 1, 1999. It was developed by Gearbox Software and published by Valve as a complete, self-contained episode — there was never any post-launch content roadmap, DLC, or expansion planned. The game shipped as a finished product. Since release, Valve has issued occasional maintenance updates to keep the game running on modern systems and platforms. Notable among these: a July 2013 update migrated the game to the SteamPipe content system and added Mac and Linux support, and an October 2019 update addressed a collection of gameplay and engine bugs. These are purely technical upkeep patches — none introduce new story content, levels, or gameplay features beyond what shipped in 1999. There are no unreleased DLC listings, no developer statements about future content, and no evidence of any planned additions. The game has been complete since its original 1999 launch.

Evidence

Store description presents Opposing Force as a complete, standalone expansion episode with no mention of additional content, DLC, or ongoing development.

description source content shipped

medium

October 2019 patch fixed a range of gameplay bugs (boss transition, weapon animations, HUD icons) and engine/security issues. Purely maintenance in nature.