Not out of the box — but the Synergy mod makes it co-op. Half-Life 2: Episode One is a sci-fi shooter game released in 2006, 96% positive on Steam (31,822 reviews), with 18 playing right now. price varies on Steam.
Episode One in co-op through the free Synergy mod. Steam lists Half-Life 2: Episode One as single-player, so it won't show up in Steam's own "games we both own" view as something you can play together — Ready Up counts it anyway, marked "Via mod", and you can hide mod-only games with one filter if that's not your thing.
Half-Life 2 has sold over 4 million copies worldwide, and earned over 35 Game of the Year Awards. Episode One is the first in a series of games that reveal the…
Steam tags: FPS, Action, Sci-fi, Singleplayer, Story Rich, First-Person, Shooter, Classic
Ready Up compares two Steam libraries and shows every multiplayer game you both have — including whether Half-Life 2: Episode One is one of them — then helps you pick tonight's game with a weighted roll or a bracket.
Or open the Steam store page.
Tired of Half-Life 2: Episode One? The Swap tab finds the closest unowned games of the same type that are newer or rated higher.
Ready Up is a free tool: enter two Steam usernames and it lists the multiplayer games you both own, runs a bracket to pick one, and suggests new co-op games that fit how you both play. Ratings, tags and player counts from Steam and SteamSpy; page updated 2026-09-09. Powered by Steam — not affiliated with or endorsed by Valve Corporation or Microsoft. How the data works · Legal & privacy · All types · Game Pass