Hidden: Rebuild

2026-09-27

Hidden: Source's code was lost years ago, and Beta 4b's 2006 binaries don't run on today's Source engine. Hidden: Rebuild rebuilds the game on the modern SDK and keeps using the original content.

It plays Beta 4b as it was. The numbers, the round flow, the Hidden's pounce, cling, aura and pigstick, the IRIS loadouts, sonic alarms and radar, the menus and the HUD are all worked out from the original game, with the maps, models and sounds loaded from your own Beta 4b install. What's new is underneath: a maintained 64-bit engine, native Linux builds, and dedicated servers for both.

Also in:

Bots for both sides, so a small server still gets a game going (bot_add, hdn_bot_quota).
The popular SourceMod plugins, built in with their old cvars: PigShove, Mirror Damage, Team Aura and more. Old server configs keep working.
Beta 4b's own anti-cheat material check, ported as it was.
The community's fixed hdn_decay and hdn_origin in the map cycle, falling back to the originals where a server doesn't have them.

The first release, v1.0.0.2, is on the downloads; the install guide walks through it. Where something doesn't play the way you remember Beta 4b, open an issue: matching the original comes first.

Hidden: Rebuild, a community rebuild of Hidden: Source (Calibre Studios, Beta 4b, 2006) on Source SDK 2013. Not affiliated with Calibre Studios or Valve.