2 things CK1 did not have were twins (or triplets or more). They were implimented in Rome and I think they would be a good addition to the game here moreso than Rome.
In addition, CK1 had several possibilities when a female gave birth: success, stillborn or death and the child dies. It did not have the 4th option, death and the child survives.
In addition, CK1 had several possibilities when a female gave birth: success, stillborn or death and the child dies. It did not have the 4th option, death and the child survives.