I know this challenge has been around for a while, this is just my take on it. I have played the challenge multiple times, and I thoroughly enjoy it.

To start, create your founder. They may be any gender, as long as their gender customisation allow them to get pregnant. You may customise their looks as much as you want, but traits and aspirations may have to be randomised (see difficulty rules). Your founder may have any name, as they do not count to the challenge, but make sure their surname is something you like as this will be kept through the generations. You can move in to any lot and have any house, as long as you can afford it with your starting money - no cheats!

Easy Rules:

• Each baby can be a different letter of the alphabet - e.g twins can be a and b
• You may have any number of spouses
• All reward traits and potions allowed - except potion of youth
• You can have as many babies as you like per generation
• You can have any career and aspiration - traits must be randomised
• You may marry and move in any spouse
• To complete the generation, you must complete an aspiration, max a skill or reach the top of a career. However, you may play on after this point, this is just where you HAVE to get to, at least

Points:
Start on 50 points
+10 for every alphabet baby born
-5 for every new spouse in a generation (be loyal people!) - unless the spouse dies
-10 for using Potion Of Youth
-2 for using reward traits/potions
+5 for every skill reached to level 5
+10 for every skill matched that you did not use to move on a generation
+15 for every aspiration completed that you did not use to move on a generation
+15 for every career completed that you did not use to move on a generation
-5 for every generation beyond the 4th that you take to complete the challenge

Medium Rules:

• Each generation is a different letter - e.g twins must both be the same
• You may have one spouse per generation
• Only fertile reward trait allowed
• All reward potions allowed - except youth
• As many babies as you like per generation
• You can have any career
• Aspirations and traits must be randomised from toddler to teen
• You can pick any aspiration when ageing to a young adult
• You can marry and move in any spouse
• To complete the generation, you must complete an aspiration or reach the top of a career. However, you may play on after this point, this is just where you HAVE to get to, at least

Points:
+5 for every bonus baby born (not the first in a generation)
-10 for every new spouse in a generation - if the spouse dies, you won't be able to have any more kids, unless you take the -5 points
-10 for using Potion Of Youth, or any reward traits (other than fertile)
-2 for using reward potions
+5 for every skill reached to level 5
+10 for every skill matched
+15 for every aspiration completed that you did not use to move on a generation
+15 for every career completed that you did not use to move on a generation

Hard Rules:

• You must have all babies in one generation - each must be a different letter
• You may only have one spouse
• No reward traits and potions allowed
• You must randomize all traits, aspirations and careers
• You can not marry any spouses, but you can move them in

Points:
+10 for every baby born
-5 for every new spouse, unless the spouse dies
-10 for using any reward traits or potions
-15 for using potion of youth
+5 for every reached to level 5
+10 for every skill maxed
+15 for every aspiration completed
+15 for every career completed
-15 for every extra generation taken to complete the challenge

Other Rules:

• You may use any lifespan you wish.
• Any of your children may become your heir, so you do have some control over your heir's traits/aspirations
• You do not have to use the points system, it's just something I included because I know some people like having one.

This isn't a finished set of rules, so all feedback is welcome!