I got to 10 generations in the save I have for Simeon and L's kids Pandora and Solomon and their line. In my present game, I have Lada who is the daughter of my go-to Spellcaster's Family with Sam Astral being her dad and her being a grandma. In my game where Morgyn and L are married, they are up to 6 generations now in their line. I am waiting for a game where Simeon and Morgyn finally hook up and have kids. Though I am starting to believe that L's love of mischief is going to be needed to make them infatuated with each other. However, eventually, it'll happen on its own. I plan on doing at least 10 generations for each line. I'm not including custom Sages like the Sage of Mastery Magic or The Sage of Vampire Magic or The Sage of Alchemy in this experiment. I'm curious to see how each line is both magically and other.
In Sims 4 I don't usually do generational games. I do in Sims 3, have generation play in my games and enjoy seeing how far I can go with family lines. In Sims 2 I would play nothing but generation games to see how far I could get my Sims line.
