I have thought of two versions of this.

One which involves supernatural beings, the other of which does not (for those who do not have or do not enjoy Supernaturals.)

This is simple....start off with an empty world.I'd highly recommend a LARGE one. Because this is going to get big.
You can delete everything in a pre-made if you'd like, or you can download one. This can come from the Sims 3 Exchange, or from Mysimrealty which has excellent empty worlds.

There will be no full time jobs available. This is not a NORMAL world. (especially for the Supernatural aspect), it is a place hidden away and not found on any map. (Thusly so, if you can, and have the mod for it, try turning off tourists and paparazzi, because paparazzi is VERY annoying. If you don't and are uncomfortable with mods...just ignore them?) Your community lots are limited.
You are allowed at the MOST (if it's absolutely necessary) three SMALL businesses--- (I.E: Grocery, Spa, Book-- if you decide to make one a diner instead, you may eat there, and take classes, but not join the culinary career until at least five generations of the town has passed.)--- and at the most TWO *small parks* and when I say small, I mean small. Little places. These will be your primary places of meeting and social function. These can not be replaced by dance clubs, bars, or anything else of that nature. They have to be parks- like, naturey- path through forest- or play ground parks. (Perhaps add a mausoleum to one of the community lots to have a place for the dead. But no one can be employed there.) And since they're small try not to grab Central Park from the Lots bin and place it on a 64x64. Build your own park(s).

If you'd LIKE and it's AVAILABLE you *may* add a beach. But only one. That's it. That's all you get.



Next is the actual gameplay part. If you've followed thus far, your town has no people in it.

Supernatural:
If you're playing it for the supernatural aspect------ no humans. You may create up to five households--- they can either be single sims, or couples, or siblings, but no already-made-large families. Try for less than five households though, so you can keep up with them. You may only have a FEW of them have part time jobs (after all eventually all the spots in a bookstore will be filled. We don't need 30 people restocking books after all.) The rest of which must fend for themselves through moneybuilding skills or...you know...kleptomania.

Supernaturals may not marry the race with which they naturally feud-- unless you attempt a Romeo and Juliet angle at some point (in which they can), in which case they may not be seen on the same lot as their respective species. (Vampires feud with Werewolves for example, they can't be seen smooching on a lot with another werewolf or vampire.) If they do at BEST they'll be immediately sent home and not allowed to communicate for a sim-week, or be forced to break up- guardians standing over shoulders-, shunned and kicked out, or at worst- and most extreme- killed. The Romeo and Juliet thing is certainly not the theme of this challenge though.

Once three generations in this town have come, you may bring a human to your island, if you wish, for story telling purposes. (Someone has shipwrecked themselves onto this uncharted fantasy island and now they're coping with dealing with creatures they've only read about in books. They're not allowed to travel anywhere else because they have NO idea where they are.) After this you may not bring in another human household until any traces of a human being there are gone again. (Not including a gravestone/ghost) If you bring a human in, they become your main character and you may not play anyone besides your human until your human is gone.

I define three generations in the town as at least two of your "founders" having grandchildren.

Not Supernatural:

If you don't do the supernatural aspect, all the rules besides the supernatural ones apply.

The richest sim may eventually buy one of the businesses, only when they can afford it, and then they aren't allowed to have any other means of money.
If your richest was working at the Grocery store, for example, and then became rich enough to BUY the Grocery store- that's the only building they're allowed to buy. Someone who worked at the bookstore wouldn't be able to buy a spa, for example.



Further Challenge: Teenagers!

Try starting off with teenagers. Once they grow up, and their kids become teenagers- those teenagers become your new 'main characters'. You may only play a teenager of each household. (If you go to one where there are two teenage siblings, you may only have one selected and play that one and must make the rest of the household fend for themselves.) The loophole being if you have a storyline going on with the teenager you're not playing, but this storyline involves a playable teen from another lot- you may play the playable teen in order to advance the storyline.




Basic Rules:
No pre-made sims.
No cheats except for ones that are necessary for function. (ResetSim for example).
NO pre-made houses. And no building empty mansions/houses and leaving them there until you can afford to move into them. This is a gateway for Vanilla sims. For the sake of this challenge, and hopefully in general, we hate Vanilla sims. If you get the money for a mansion you may build one on the lot they already live in, or move them to an empty lot and BUILD the mansion.
Once it gets to the point where everyone is related to each other by some means on the family tree and you can't start a new generation unless you make a couple of kissing-cousins, THAT is when you may add up to three new households. (If you're playing Supernatural, you may add one household of each new sort of Supernatural again.)
Once ten generations in this town have passed, you may put down your first place of actual business. (Hospital, City Hall, Police Station, whatever.) Naturally, once you do, you may finally give someone a full time job. After this you may place down ONE additional business for every new generation. (The Eleventh could have another, the Twelfth another, the Thirteenth another.) But no dance clubs or bars, still.
If at this point you aren't bored to DEATH with this challenge and wanting it to END by GEORGE, by Generation 17, you may have someone with new and innovative ideas who adds ONE bar *or* ONE dance club, or anything of that nature.




This sort of thing will eventually lead to a sweet world full of unique Sims, in depth story line, and creative possibilities. I haven't thought of an end to this challenge. I suppose when you hit generation 20...?....That sounds good. Generation 20. Or when you're ready to murder me because I've made this so long and complicated.

If however you're not ready to murder me, and have grown fond of this-- for all the work you've put in----
I thought, after this, it'd be a totally awesome place for you to create a new sim, or choose one of the sims alive in it now-- to start a new challenge. Someone else's! :3 Yay. You just built a high class world. Aren't you PROUD?



I don't know how to do points systems.

Um.

If anyone's interested in this and can think of a good points system--- post it? :3

Otherwise constructive criticism would be FANTASTIC.

And if you do try this one out, no matter how you modify the rules, it would be awesome to hear about it.

This sounds a lot like this challenge. You might be interested in checking it out.

As for the points system, you could give points for each rabbithole, community lot, and household by the "end" of the challenge. Possibly count up all the Sims in town as well. I'm not going to determine how much each one is worth, not having played it, but the houses and community lots would probably be worth more than rabbitholes, based on effort spent in building them.

So, -grabs piece of paper- If you are lazy, or your computer might crash, HOW DO YOU EVEN GET 5 FAMS. My Sims 3 crashes every 1-3 games I play. NO WAY I could do that much. -looks for some CC for 2 days- Nope. Nothing. GET ON IT SOLDIER!

You make five families in CAS (with a total of up to 10 sims) and move them into a town. You rotate through playing the families, and, at least in the beginning, your game might even run faster, since there's almost nothing to load.