The Royal Kingdom Challenge(Sims 3 version) *Revised
Edit: This has been updated a bit since I posted this a number of years ago. Thanks so much to nobodysgirl333 for revising the rules
I just edited the rules a bit for this challenge since it was originally made for the sims 2 and I figured I’d post it here. I then forgot about it for a few years and nobodysgirl333 updated the challenge herself so most of the improved things are her doing

I just reworded some things and changed a few minor rules, along with fixing some typos. I originally copied this from the original site and just changed a few things but it's been changed quite a bit now. The introduction and ending comment are still the original ones but the rules have changed a lot to fit the sims 3. The original premise and idea is the same as the sims 2 version though. With that said, the challenge rules and everything are below
Do your Sims have a longing for days gone by? Do they want to shout ¡Huzzah! Long Live the King and Queen! Do they have a hankering for good old-fashioned servitude? Then it is you duty to transport them back in time several hundred years to live in Good Old Simland! Simland has a King and or Queen that presides over all of their loyal subjects. It's up to you to make the strongest Royal family that you can. The fate of the Kingdom depends of you!
Discuss your tips and strategies and any need for help here!
Royal Kingdom Challenge for Sims 3
The Goal: The point of this challenge is to make a themed neighborhood with a royal family, nobility, merchants, and peasants/farmers and reach 5 generations.
To begin you must make a new neighborhood and set aging to normal.
Aging can be edited slightly but it should be similar to the normal lifespan.
You may choose to turn off story progression and use the sims 2 style aging, playing each family in rotation. Or you may choose to leave it on but you should use some kind of mod that let's you alter the story progression like Nraas Story Progression mod so that your families don't get all screwed up when you aren't playing them.
• Make 1 King and Queen for your royal family in CAS
• Make 3 or less families that will become the Noble class
• Make 4 or less families that will be the Merchant class
• Make 5 or less families that will be the Peasant class
• You do NOT have to make that many families you may modify it to fit your playing style
• You may not use any cheats except where specified
Rules for the Royal Family
• All money cheats are acceptable
• You may use cheats for building their castle
• You may download a castle for the royal family is you don’t want to build one
• The first-born son* of the current King and Queen will become the heir to the throne and must never move out of the house except to go to Boarding School (if you have Generations)
• The heir to the throne may only marry a Sim from the royal family or the Noble class, but they may have lovers of any class (They can marry as close a relation as the game allows)
• The heir to the throne must be the legitimate son* of both the king and the queen.
• Any illegitimate children of the Queen would not be a prince/princess but could marry a non-heir Royal or Nobel
• Women of the royal family are not permitted to have a job or live alone
• Non-heir Peasants may move in as servants to cook and clean
Rules for The Noble Class
• You may use the motherlode cheat only two times
• You may use cheats for building purposes only
• The first-born son* will be the family heir and must never move out of the house except to go to Boarding School (if you have Generations)
• Only legitimate children can become heirs
• The HEIRS may not marry below their status
• Women are not permitted to have a job
• Only one life fruit is allowed per Sim
• Non-heir Peasants may move in as servants to cook and clean
Rules for The Merchant Class
• You may use the motherlode cheat only one time
• You may use cheats for building purposes only
• Although the eldest son* traditional becomes the heir, if the eldest becomes enemy’s with his father, any of the children may inherit their father's house and fortune
• The heir must never move out of the house
• The HEIRS may not marry below their status
• Only single women may have jobs
• Only one life fruit is allowed per Sim
• Children can only attend Boarding School(Generations) if their family has at least §5,000 in their account
Rules for The Peasant Class
• You may not use any cheats (except for building purposes only)
• Anyone and everyone are encouraged to have a job since they will have very little money
• Although the eldest son* traditional becomes the heir, any of the children may inherit their father's house and fortune
• The heir must never move out of the house
• Children of this class are not permitted to attend Boarding School(Generations) since peasants didn’t have much of an education
• Since they are the lowest rank, peasants may marry anyone but royalty.
• You may not use the life fruit on a peasant since they generally would not live as long anyway
• The only service NPC they are allowed to hire is the babysitter
General Rules
• Unless otherwise specified you may not use any cheats. No mood or aspiration cheats and no hacks that alter a Sims mood, personality, aspiration etc. You may use cheats to fix glitches should they occur.
• Use the randomize button to pick traits.
• To avoid confusion try to stop your Sims from having an affair until after the heir is born
• Since reliable birth control was not used in the old days, you must choose "try for baby" each time your Sims woohoo.
• Women always take the status of their husbands so make sure it is always the man who proposes
• Illegitimate children below Royalty will take on their mother's class
• You should assign a hair color to each Class for the townies so you know which class they belong to (example: All townies with red hair could be considered of the merchant class). However since Townies do not have a family tree they are less respectable and should not belong to the Royal or Noble class
• NPC's are servants so they may only marry Sims from the merchant class or lower
• You may use moveObjects on only to decorate and move Sims if they get stuck or there is a glitch
• You are encouraged to use custom content that fits the neighborhood theme. Pick a theme and try to make your neighborhood fit that theme as much as possible.
• Try to use only objects that fit within the theme, this means no TVs, computers, etc. if you are doing a historical theme for your neighborhood. You may however use objects in the small electronics section such as fire alarms. You may also use the smallest stereo in the Royal and Nobility houses since they would have had paid musicians to play for them at dinners and parties.(You may have a tv or other such things if you wish but try to download something custom that fits the theme slightly better)
• You may not delete gravestones
• You may use all rewards unless stated differently. If doing a historical theme, try to hide any modern looking rewards in a basement or attic.
• Hacks and mods are allowed for the purpose of making the neighborhood more historical accurate and Hacks and/or mods that make the game easier are not permitted.Any story progression mods are allowed. You can use those instead of turning off story progression but make sure to set the setting how you want them. AwesomeMod is also allowed but don't use any features that would make the challenge easier or give you an unfair advantage.
Career Limitations:
• Royalty would be limited to Business, Military, Politics, and Professional Sports.
• Nobles are the same as Royals
• Merchants are limited to Journalism, Law Enforcement, Medical, and Music.
• Peasants would be limited to Criminal, Medical, Military, Culinary, and Music.
• Science would be limited to your Magic family.
• ONE child of each class per generation (not per house, only per generation) could go to ANY job.
Profession and Self Employed Limitations:
• Royals and Nobles cannot join a profession.
• Merchants and Peasants may join any profession
OPTIONS
• If medieval isn't your style you could also play this challenge with another theme such as Renaissance, Regency, Victorian, or fantasy.
• You can add a church/monastery or abbey to you neighborhood that you can send Sims to that you don't want to marry (You could edit the setting with a story progression mod for them so they never marry and you may want to check up on them once and a while).
• You can start the first King and Queen as young adults
• To keep track of who belongs to what class you can have each class have a specific hair or skin color (ex. all peasants could have brown hair or green skin).
• You can add one household for the town witch or wizard (it helps if you have Lady Ravendancer Goth’s Book O’ Spells from EA Store). The heir to that family would have no cheat restrictions and could join the science career track but would otherwise have to live by the rest of the peasant rules.
• If you can’t decide which theme to choose, try advancing the time period every one or two generations. Then you could start at medieval, then renaissance, colonial, regency, victorian etc. If you find the custom content for it you could even start with an ancient period like Egyptian or Roman.
• You can make ghosts if you want them. However, remember that an heir to a family cannot inherit their parents place until they are dead and gone. Also with the quickly growing population, you don't want to many Sims hanging around far longer than their regular life span. So you might want to use the ghost feature sparingly.
• A Noble or Royal Sim should not marry a Sim of unknown parentage. A good bloodline is very important.
• Gravestones should be kept on the home lot for royalty and noble families and the graveyard should have specific sections for the other classes. Merchants and Peasants may keep gravestones on their lot if they so choose.
• Only the Royal and Noble classes are allowed to have carriages (Cars) but they must have a garage to make them less discreet
• If you have pets then use of horses is highly recommended. Royal, Noble and Merchants may buy horses; peasants may only adopt wild horses. Only the magic family may adopt a unicorn.
• Only your town wizard/witch or equivalent are allowed to use the Robot making bench since a robot would be considered magic.
• Only Nobility and Royals would be allowed to purchase a Robot. Servo would be considered a live in servant of the house.
• Only the head of household may purchase a business venue and it must be passed on to their heir. Peasants may not purchase venues.
• NO AMBROSIA for anyone other than the Royal family.
Scoring
Count up all the points when you reach 5 generations. If you keep track of points you must play by all the rules, but you don’t have use the scoring system. Please be honest.
• 1 point for each generation reached
• 10 points if every heir for all classes is the first born son.*
• 1 point for each lifetime wish fufilled
• 1/4 point for each family friend the royal family has
• 2 points for each heir to the throne who marries another royal
• 1 point for each award won and received at City Hall.
• 1 point for each sim that has 100,000 lifetime reward points (add their current total with the amount spent on rewards plus 1 point for every additional 100,000, so 200,000 would be 2 points)
• 1 point for each different color ghost you have on the lot
• 1/2 point for each set of natural triplets
• 1 points if you manage to collect ALL the different types of ghosts on a lot
• -2 point for each Sim that was purposely killed (unless it is by another sim as part of the story. If it was only for your own convenience then you lose the points)
• -1 point for each Sim that marries below his or her status
• -1 point for each infant, toddler or child that gets taken by the Social Worker
*If you want to make a matriarchy (society run by women) instead then you get then all heirs are first born daughter
**If you don't have all of the Expansion Packs simply ignore the rules or bonuses that don't relate to you.
Remember, this challenge is very flexible so it can fit your personal tastes. With this challenge you can unite all the families in a neighborhood and give it some sort of structure and goal. If you are not playing for points feel free to bend the rules a bit to fit your playing style, but don't be afraid to try something different then you normally do!
Taken from Fanciful Sims.
There's also some custom content that has been linked too in the comments as well as an entire town of medieval stuff I believe so if you want those links you can find them in the comments

If I missed editing something than please tell me. Also, any suggestions are welcome.