As such, it is recommended to maintain a high degree of separation when marrying and avoid union between close relatives, unless there is a significant advantage. The risk is higher when the parents are more closely related (specifically, with more shared ancestors). Note: Some genetic traits can also be acquired later in life, such as getting Stutter from one of the outcomes of a childhood event.Ĭharacters whose parents have shared ancestors are at risk of being born with the Inbred trait, severely limiting their skills, fertility, and lifespan. Whether or not a pregnancy results in Twin, it is decided at conception all of the twins' traits (including their genders) are decided at birth, as usual.The baby may get the Sickly trait and the mother may die while giving birth.
Pregnancy chance is also affected by FERTILITY_BASE_MULT = 0.5, and the following relationship multipliers:Įssentially, everything is decided at birth and not at conception: Note that pregnant women can be incapacitated by a Troubled Pregnancy, triggering a regency if she is a ruler in her own right the Final Months of a pregnancy will always trigger a regency for female rulers unless the Pregnancy Flavor game rule has been set to "Limited" or "Off.". Two months after conception, the player will be notified and the wife will gain the Pregnant trait and approximately seven months later, a child will be born. It is also possible for the wife to get Pregnant through events, e.g., if the male character becomes rather angry with the death of his firstborn son, or through Seduction focus events. Without the Conclave DLC activated, the ambition Have a Son/Daughter increases fertility by +25%. With Conclave DLC active, it is recommended to get the ambition Groom an Heir, which increases fertility by +20%. Or a willingness to advance children through your line of succession with disqualification or murder.Įven with two Genius parents, there is no guarantee that the offspring will be a Genius too, but if the player character raises several children, the odds of at least one of them getting this trait are moderately high ( ~66% in a scenario with two Genius parents and three sons born).Ī married couple's fertility decides the ability and likelihood of conception.Since genetic traits are random, breeding programs frequently require either: With that being said, some of the lesser negative traits (such as Clubfooted or Lisp ) can be somewhat useful for getting a few more points to use in the Ruler Designer, as typically about 85% of the born offspring are unaffected and it is usually possible to ensure that one of them becomes the heir(ess). If the player somehow ends up with one of them, it might be a good idea to (if possible) marry someone with a positive trait opposite in effect to it, as that will somewhat decrease the chance of the heirs having mediocre attributes and relations penalties because of it. With a streak of bad luck, bad genetic traits could end up plaguing a dynasty for generations to come. On the other hand, negative genetic traits should be avoided when possible, unless the advantage cancels out the risk. With a little bit of luck they could end up staying in the family for a long time. As the positive traits are quite rare, the player is recommended to go out of their way to obtain them.