For players who enjoy bending the rules of the game, the community at Fearless Revolution maintains cheat tables for CK2 3.3.3. These allow for enabling achievements with mods or using the console without penalty.
If you are a new player who just wants to experience the base game and modern DLCs, let Steam install the latest version (3.3.5.1) . You get all the bug fixes and stability improvements without any hassle. ck2+333+download+upd
If your game launcher displays an incorrect checksum string, multiplayer connections will fail. For players who enjoy bending the rules of
Before installing a new version of CK2+, you must delete all old mod files in the Documents\Paradox Interactive\Crusader Kings II\mod directory. You get all the bug fixes and stability
If your game is not already updated, Steam should automatically start downloading the latest available patch. By default, Steam always keeps your games updated to the most current version.
Crusader Kings II v3.3.3 Update: Ultimate Guide to Downloading and Installing the Patch
The ultimate destination for downloading and updating the patch is through official storefronts like Steam, or via the Paradox Interactive Forums for standalone manual mods and total conversions.