A weird combination of RPG and Grand Strategy, unique of its kind. You play as a great family in the middle ages and have to try and create history.
The game becoming free to play is only the base game, which only allows you to play as catholic rulers. That is good enough to give a first impression on whether or not you will like it, and see if you should buy DLCs. A good DLC recommendation list is:

https://www.strategygamer.com/articles/crusader-kings-2-dlc-buying-guide/

A weird combination of RPG and Grand Strategy, unique of its kind. You play as a great family in the middle ages and have to try and create history. The game becoming free to play is only the base game, which only allows you to play as catholic rulers. That is good enough to give a first impression on whether or not you will like it, and see if you should buy DLCs. A good DLC recommendation list is: https://www.strategygamer.com/articles/crusader-kings-2-dlc-buying-guide/