You must start in a fresh unplayed file and with a brand new Sim. All random traits must be chosen from the start of legacy /w the exception of 2nd generation onward may carry one 1 of the founder's traits as a family trait. You may choose to deleteallhumans if you like.
IMPORTANT. As a mass money tree farmer in a non-legacy game, this is certainly broken. While I have yet to start a Legacy game, not mandating a fresh game means a previous money tree garden in the neighbour's house can be raped for money instantly. An array of 100 perfect money trees can be harvested in less than a day and net approximately 100K. Money tree's money output completely dominates whatever gardening normal plants can generate (barring perfect deathfish-duplicating omni plants).
"Your founder, and only your founder, cannot marry a rich sim. All future generations may marry any sim, rich or otherwise.
Money Legacy points capped at 20 total (2 million in net worth)
+1. This is very important as aforementioned money exploits can result in massive ballooning of money. As the ingame description for money tree states, inflation really occurs, and quickly for that. Capping it solves it pretty much. Over 10 generations it is possible to (with obtaining of more unknown special seeds daily) to get arrays of money trees relatively easily. Money Legacy points capped at 20 total (2 million in net worth)