Welcome to a new The Sims 4 Legacy.
These are the rules I play by during this legacy:
Strict Equality: The founder may be of either gender. However, only children of the opposite gender to the founder are eligible to be named heir. This repeats itself for the next generation (the next heir must be a different gender than the previous heir) so that each generation will have alternating-genders as heirs.
Foster: Children who are adopted are eligible to be named heir. Naturally born children are not eligible to be named heir unless there are no adopted children, at which point they become eligible for that generation.
Random: The title of heir is randomly selected from the pool of all eligible children. Every time the eligible pool changes size, The heir must be re-rolled using the new pool.
For more information on the rules, go to The Rules.