I hope you'll understand me, because my english is horrible

How to begin:
Okay this is it.
1. Create a Sim, an adult and two cats, a female and a male (also possible with dogs).
2. Buy a place and build a house and then start of with 100 Simeloens.

General rules:
Now the Pets have to get jobs. This is the only way to get money. With the pets. The Sim stays at home and locks after himself and the animals. Sometimes he can go into town. But there is no way, that he can earn money. Not even by painting. The cats can have wohoo and get kittens. You can sell them and earn Money.

Important is:
1. The challenge ends, when you have all stuff to survive and you have 20.000 Simeloens.
2. You lose when your Sim dies by age. You get a second chance if he/she dies of fore ect.
3. You can use forcetwins . This is the only cheat and it will cost you 10 points, no hacks, nothing but this cheat.
4. The Sim should be alone, because it is difficult if there are more mouths to feed.
5. You can get some rogues if you want.
6. If an animal dies you can buy another.

Points:
+50 for every little dog or cat
+100 for every sold cat or dog
+50 for everytime your pet get a higher joblever
+100 when a cat/dog get the highest joblevel
-100 when an animal dies
-10 for everytime you use forcetwins
-100 when an animal loses their job
-50 when an animal loses a joblevel

I tried it too and I think it's funny to get all those kittens. I think it's better to do this challenge with cats. I hope you like the idea, but if there are some things you don't like, please tell me and I hope i can solve the probem or explain something I wish you not too much trubble

What about pet jobs? Are those allowed?

I wouldn't mind trying this out, I like any challenge that makes buying stuff for my Sims more difficult. (The house must start out empty, right?)

Can the adult invite another sim to live in as a roommate and help the household earn money?

Of course are pet jobs allowed. Sry. I ment that by job. Yes the gouse should be built by yourself
The Sim can have a roommate yes, but he can't have a job that's the challenge. Only earning money with pets.

You do realize that a roommate means additional supply of money, do you? What are players to do with the additional supply of money that is brought by the moved-in guest? Donate it, or use it? You can actually make a lot of best friends in the game and invite them all to move in with you. Once they become your house guests, they may bring large wads of simoleons, which can make your household rich. To put a limit on this, you may want to limit players to only one roommate.

Just so I understand: the house cannot start out with any furniture, plumbing, cabinets, appliances (basically anything from Buy Mode).

@CrèmedelaCrème: You are making me headache Yes I see were the problem lies. There is just one rommmate allowed. And the money he brings with himself can be used for the house if it's not more than 8.000 Simeloens. More should be used for clothes, or the garden. For example. You already earned 1000 Simeloens, than a rommmate comes and brings 9.000 Simeloens, ou can ue his 8.000 and his other 1.000 you have to spend on nothing for the house. So that the result is, that you have your original 1000 and not more.

@lorinsv60: You can't have an Maxis house.You build the house yourself, the walls, how you paint it... this is up to you. The house is built by yourself.

Can you move out the one roommate and get a new one?

No, I'm sorry but just one

will give this ago