How it works is that people in the comm submit a sim to be used as a founder, and everyone votes on which sim we'll use. Then we all use that one sim to start a legacy, and post our version. It can be interesting to see what that sim gets up to in everyone's game, and how their kids look. Usually posts are required weekly or fortnightly to stay in the challenge. There isn't really a winner, but you can aim to get to a certain generation.