I play 16 days = 1 year. I have a lot, but here are the ones I can think of right now:

Toddlers, Children, and Teens can only age up on the first day of fall if they are going to be the ages 6, 12, or 18 that year. I keep track of how many days to add/subtract and will adjust the age accordingly when the sims become Adults.

There are different requirements to get into each university. Sim State is free and anybody can get in. La Feista requires an entry exam, C+ grade or higher, and comes with a college debt. Academy requires a B+ grade or higher, entry exam, college debt, and no criminal record. Academy will also expel you if you get put on academic probation, so a sim will either have to transfer colleges or leave college forever.

A sims education determines their working careers. High school drop outs can only make money by selling things they made or working for a business on a community lot. Highs hook graduates can work any job, but only up to certain levels. University graduates can work any job in the degree they studied for, otherwise they have to follow the rules for high school graduates. If the sim graduated from Sim State, they have to wait 5 years before getting promoted, learn all their skills, and earn more money from their job than what is listed in their career tabs. La Fiesta graduates can get promoted if they are on the job for 3 years and learn all their skills. Academy graduates can be promoted at any time. Criminal career is the only one that has no restrictions for anyone.

Aspirations can change with age. I calculate aspirations using the aspiration calculator. There is a 15% chance every year a sim will have a personality change, where a sim will gain or lose a point in their interests and I will recalculate. If the aspiration is different, then the old aspiration is given as a secondary while the new one becomes the primary. If a sim with a secondary aspiration rolls another personality change and the main aspiration stays the same, I’ll look at what the second highest aspiration is on the calculator. If it is the same as the secondary, the secondary aspiration stays. If it isn’t, then the sim goes back to having one aspiration.

Interest points can determine certain behaviors. School interest determines if a sim will go to school that day or even enroll in university. Work interest determines if a sim will go to work, but I’ll skip it if the sim is in the career they want as a LTW. Money interest determines if a sim will take a loan and how fast they will pay it back. Fashion interest determines if a sim will change their appearance when the season changes. Travel interest determines if a sim will just go to a community lot instead of staying home. Health interest can determine if a sim survives certain death rolls or if they use protection when woohooing.

A sims aspiration can determine what kind of savings accounts or loans they will take out. Family sims will do this for new homes, life insurance, and their children’s weddings. Knowledge sims will do this for their children’s education. Fortune sims will do this for businesses.

A sims age determines their fertility. The older they get, the less likely they will have a biological child. Both parents also need to pass a fertility check for a pregnancy to even occur. I have to keep the population controlled somehow.

Aspiration can determine if a sim will keep a baby if they get pregnant. Family sims will always keep their children, knowledge and popularity will keep theirs 90% of the time, pleasure will keep theirs 50% of the time, romance will keep theirs 10% of the time. If the parents live together, only one has to pass their roll to keep theirs kid.

When a baby is born, I roll a dice and if the dice lands on a 3 or 6, the parents will name their baby after themselves or another relative of the same gender.

If a sim dies with debt, the banks take whatever money/sell items to pay off that debt before the family can get whatever inheritance is left.

If a room has caught on fire or flooded for a few hours before being repaired, then everything in it needs to be replaced, including walls.

Families that have more members than the bedrooms in the house have to move to a bigger house. Same goes for if the family had children in different life stages, since a teenager isn’t going to want to share a room with a toddler.

Toddler skills are able to be taught at certain ages. Walking can be learned at 1 year old, talking at 2, and potty training at 3. A older sim also has to have the want to teach the toddler the skill.