Egyptian Succession law - any ideas?

[Achab]

Out of curiosity I introduced the Egyptian Succession law when my current monarch ended with no sons. The succession line now lists women from the ruler's family exclusively, but looks like it is rearranged every couple of months. Sometimes one of the rulers daugthers pops up as the heir apparent and then she is replaced by a distant relative I havent been even aware of. The picks seem to be completely random, even age of the new heir varies from 0 to 80 so its probably not a factor. To me the succession is determinated completely at random and it changes quite often.

Does anyone have any experience with the Egyptian Succession and any clue how the heirs are actually determined?

 

[Wave]

Egyptian succession always seemed random for me.. I think it's something like

If oldest child is female, she will become a queen but if she isn't then oldest (or was it even second oldest or something weird) will become new king.

I'm not absolutely sure about this but i think it's something like that

 

[lucaluca]

it should be explained in the tooltip? I believe it is so that male and female rulers will alternate on the throne, so if the ruler is male the successor will be female, and vice versa.

The problem is that there is really no need to use this law apart from a role playing perspective... i seldom had a ruler without male children, and when that happened a brother or the son of a brother took the throne without any unrest or civil war.
I hope the nest expansion will use the same mechanic that seems to be in CKII, i.e. at every succession there will be an automatic risk of civil war depending on the strength of the claim of the heir... this way a female ruler could be useful to avoid civil wars when there are no male heirs with strong claims.