Each DLC on Steam has a unique App ID. You can find these on SteamDB or the Steam store page URL. For example, The Sims 4 – Vampires DLC ID is 123456 .

In simple terms, Steam stores a list of which DLCs you own in a local file called config.vdf and also verifies this with its servers. CreamAPI intercepts the communication between the game and Steam’s API, tricking the game into thinking you own all DLCs—even if you only bought the base game.

Many users justify CreamAPI by pointing to exploitative DLC practices:

If the risks outweigh the rewards, here are legal ways to get DLC for cheap or free.