1. In your Steam library list, right-click on Civilization 6 2. From the pull down menu, select Properties 3. About the middle of the opened properties window, click on Set Launch Options... 4. Insert the following line as is, with the quotes and the %command%, but using your custom path: "C:\Games\Steam\SteamApps\common\Sid Meier's Civilization VI\Base\Binaries\Win64Steam\CivilizationVI.exe" %command% 4.1. For DX12, replace CivilizationVI.exe with CivilizationVI_DX12.exe 5. Enjoy add-free civ start.