Here is a few rules I play my legacy with:
- No cheats or mods (money, mood cheats etc)
- No use of the fertility treatment reward
- Traits randomly rolled
- LTW randomly rolled with a dice
- LTW must be achieved by death
- Sims grow up on the day the first birthday notification pops up, never before (Normal Lifespan)
- Graves must stay on the legacy home lot
- Spares moved into a home, no use of the “kick out” option
- Spares must be in some sort of a relationship before moving out
Those are just a few basic rules I go by, more will be added if I think of them.