This is a boolprop EPIC Legacy Challenge. Rules are here at the forum, or here on the blog. Basically it’s like a simplified, less-restrictive (and less complicated!) version of an Apocalypse Challenge – many things are blocked at the beginning, and through the generations you access different areas.
Chapter List is here.
We are currently on the eighth generation, and the heir is Crystal:
Winner of Best Sims 3 Challenge at the Boolprop Golden Plumbobs 2017!