A popular tool for Steam games that focuses on modifying the Steam API.

Tools like CreamAPI or SmokeAPI replace or intercept the game's original steam_api.dll file. When the game asks Steam, "Does this user own the Biotech DLC?", the modified file returns a "Yes" regardless of actual purchase history.

Unlockers often do not include the actual content files (art, sounds, code). Users typically have to download these expansion files separately from external repositories and place them into the RimWorld Data or Mods folder for the unlocker to work. Common Unlocker Tools

While the game is distributed DRM-free by the developers, it still checks for ownership via the platform it is running on (usually Steam). Unlockers attempt to bypass these checks to enable premium features. How DLC Unlockers Work