Cepheus Protocol

Cepheus Protocol is an Open World RTS Military Survival Game. Play as the CERC hunting Patient 0, maintain Quarantine camps, fight dangerous mutations & Rogue Civilian Combatants . There’s nobody else coming, it’s up to you now.

Region: Global. Check that the key's region matches your Steam account's country before buying — region-locked keys can't be activated elsewhere.

What you get: one unique, unused product key, shown on your order page (and in your account) once payment is confirmed — usually within minutes, and at most 24 hours. No physical item is shipped.

How to activate: open the Steam client, choose Games → Activate a Product on Steam, accept the subscriber agreement and paste your key. The game then appears in your library, ready to download.

Requirements: a Steam account and the Steam client. System requirements are set by the publisher and listed on the game's Steam store page.