Imagine playing pinstars legacy challenge, except using the short lifespan instead of normal!
Well there's already a speed legacy challenge so here is the link: The Speed Legacy : forums.thesims.com/en_US/discussion/400493/
The rules are the same as the rule of legacy challenge made by pinstar except the one below! Any rules in the original rule that contradict the rule below is not applied.
So other rules are:
1. Set the lifespan to short instead of normal (no aging mod except if it makes it even shorter)
2. No birthday cake/party, you have to forget their birthday (making your sims sad how fast their lives have past)
3. You can't move out anybody, you have to wait for one of them to die (killing them is legal)
4. No age prolongation item is allowed, bodybuilder aspiration bonus traits is allowed
5. You can change aspiration whenever you want but the main aspiration is still the one that is scored. (the one that you chose in cas or age up menu)
6. No dragging anything to NanoCan Trash Can, you can still use it by having sims to throw the NanoCan Trashcan.
7. If the notification for a female sims that they are about to age up, (usually 2 days before aging up) she can't try for baby because it can prolong her life.
8. No pregnancy test, if you're not sure try again.
9. If they're still alive any heir should and can only be best friend with their grandson! (not tested this yet! I suppose when a sims are dead they will lose their best friend status)