Bastard son claims legitimacy

[postm00v]

In my recent game, my ruler had 4 sons - 2 legitimate sons and 2 bastards -. Everything was going as it should go, but then I got an event which legitimized (?) the first bastard son.
Even though he was the third born son, he moved up in the inheritance line, making him my heir ! I mean, if he wants to legitimize himself, fine. But how on earth can he move up and 'overtake' my firstborn son ?

Now my British Empire is destined to be ruled by a bastard ! :angry:

 

[Grayfox]

What are your inheritance laws?

If you're using Consanguinity, then it's likely that he is your strongest son (in terms of prestige). This event usually fires for me when a bastard son has accrued a decent amount of prestige in the first place, so I think this is the likely cause.

If you're using Primogeniture, then this is a bug.

 

[postm00v]

Using Semisalic primogeniture. For over 100 years actually, so must be a bug.

 

[Ivan Rogov]

I recently had an event where a bastard son of mine lost his, uh, bastardy and demanded I change my inheritance law so he could inherit. I believe there was a % chance with each choice that he would no longer be considered a bastard. I refused, saying "my law is my law." Did you get this event and change your law by "accident?"

 

[postm00v]

Found out what happened. The event changed the inheritance law, like you said. Thanks for pointing it out.