It has been said that this game is all about your dynasty. But is the "10% of dynasty prestige boost for initial prestige" enough for the game not to be just individualist race. I mean, how benefical is it my score to care about my distant relatives and siblings?
Dynasty prestige is about titles held. So while a king might have 10k prestige, the title only gives 120 to dynasty prestige, for each king that has held the title, and of course prestige for the ducal/county/barony titles. So to crank out dynasty prestige what you need is lots of titles, one way to do that is get a lot of your own, another is to create cadet branches with sons, spreading your dynasty everywhere.
For instance the Capets, while kings of France, and powerful, have very few members. Unless that is resolved, the dynasty will have little prestige, even though the individuals will have high. The Arpads will tend to have significant prestige since they seem to spread everywhere.
In my current game, bout 50 years in, have the Capets with 272 prestige, the Arpad have 476, and the Piast have 790.
Will that 10% make a huge difference in prestige of a character by the end, probably not, though it should help in marriages. It does cause me to want to spread my dynasty though, as I can't stand that the Hungarian and Polish rulers' dynasties are more prestigious. I must usurp their thrones, and put a brother on them.