So, I've got a new idea for an expansion pack I've been working on. I'm calling it Farm Life for now, though my other idea would be 'Farm Days'. Basically, you would play your characters living life out on a farm. You would start with a somewhat small lot, and your lot could grow and expand as you grew more successful and bought out the property around you. As your game progresses, you want to grow the best food and raise the best animals, while trying to keep your basic needs under control, too. I think this would be a lot of fun to have as a game choice, and it doesn't need to be as complicated as it might sound. I'll go into further detail now.
These farms should be set in modern time (though possibly a western cowboy-era setting could work) on the far edges of the town you live in. The closer to the center of town you get, the more urban it becomes, with community centers and small homes. Your farm would be rather distant from the middle of town, allowing you to expand your land.
Edit: I've decided it would be a better idea not to include dogs, cats, or horses in this game unless you already have the Sims 3: Pets expansion. As several people have mentioned, adding these animals into the game would make the Pets expansion useless. Instead, when you begin your game, you will be able to purchase a variety of animals: Cows, sheep, goats, pigs, ducks, chickens, alpacas, rabbits, and turkeys. (This is subject to change- animals can be removed or added. What do you think?) As always, you can adopt more of any animal- but the BEST animals will be the ones you spend more money on to buy from the market, such as prize-winning bulls. These animals, while more costly, would be more successful on your farm. You can't customize anything but horses, dogs, and cats(If you have the Pets expansion), but you would have a variety of breeds and variations to choose from instead when you want to adopt/purchase something else. Animals can be bred, too, of course. Your Sim will find the most success in breeding the best animals; the best bull to the best cow, for example. The calf would then be worth much more than an average calf, and it will be able to produce more for you. Here are some of my ideas for what each animal could be useful for:
Cattle(Female): Milk, meat, breeding
Sheep(Female): Milk, meat, wool, breeding
Sheep(Male): Meat, wool, breeding
Pigs(All): Meat, breeding
Goats(Female): Milk, meat, breeding
Goats(Male): Meat, breeding
Alpacas(All): Meat, wool, breeding
Ducks(Female): Meat, eggs, breeding
Ducks(Male): Meat, breeding
Chickens(Female): Meat, eggs, breeding
Chickens(Male): Meat, breeding
Turkeys(Female): Meat, eggs, breeding
Turkeys(Male): Meat, breeding
Rabbits(All): Meat, breeding
All animals can be sold to market for meat purposes- you can't kill animals for meat on your own. You can enter your animals in livestock shows so that judges can decide which have the best qualities, and the more ribbons they win, the higher their price. You can also put up animals to be sold to other farms, which will pay a lot of money for prize-winning animals.
Also, if you DO have Sims 3: Pets, there would be an option to train you dogs to herd, for example, to get your horses, cats, and dogs involved into the farm life.
Of course, there has to be a way for you to earn money! Your Sim could earn their money on the farm, by selling produce (Crops, milk, wool, etc.) and animals that they raise. But they can also work elsewhere if they get successful enough. While farmhands manage the farm, your Sim could leave to work elsewhere if you want them to. Different animals and crops will be worth different things, too. While some crops will be more expensive to plant and care for, they will yield more profit. You can also earn money from winning ribbons in livestock shows and crop competitions.
Farmhands would be under the 'services' you could hire. You could hire up to a certain number of farmhands; ten, maybe, or a dozen. While you can't control the farmhands, you CAN assign them to certain parts of the farm; one farmhand may be assigned to care for cows, another to pigs, and another to care over a tomato garden. The farmhands could either 1. Arrive each morning and leave each night, like a maid, or 2. live in a smaller home elsewhere on your farm that you assign them to live at. But with farmhands, you aren't struggling to care for a massive farm all on your own.
While you can expand your land as your farm grows, you can't expand it indefinitely. This means you will have to make decisions about what animals/crops you want on your farm, because you can't have everything. To expand, you will need a higher amount of money for each larger expansion, making your land larger and allowing you to have more animals and crops. The larger the farm, the more successful you can ultimately be.
There would be a wide variety of crops to choose from and plant. My ideas are as follows. Fruit: Apples, peaches, oranges, grapes, tomatoes, bananas, blueberries, strawberries, pumpkin, cantaloupe, and pineapples. Vegetables: Cucumber, carrots, potatoes, cabbage, spinach, onions, and turnips. (Fruit and vegetables subject to change; things can be removed or added. What do you think?) Certain things would cost more than others to plant and grow, but would be more profitable. You can also enter these in contests to be judged, and your farm will become more famous as you win ribbons.
It matters. The more popular your farm, the more demand your products will be in, and you can sell things for higher prices. You can gain popularity by winning livestock/crop contests, horse races, and by keeping your produce on the market at all times. If your farm is very popular, people may come to visit it more, and will give your farm donations.
If your farm looks appealing and offers good livestock/crops for good prices, people will come to visit your farm more. The more people that visit, the more popular your farm grows, and you can receive donations.
This will be an expansive category. I'll explain in several sections. (All of this is subject to change; none of these items have to be added, or more can be added. These are just my ideas. Let me know what you think of them)
Wagons: Wagons can be pulled by oxen or draft horses. They can be used to transport crops, animals, and supplies.
Carriages: You can hook your horses up to carriages and they can take you into town like a car would. You would still have cars, bikes, etc., of course.
Any farm tools should do. Shovels, plows, scythes, axes, watering cans, etc.
Greenhouse: For crowing crops such as pineapples and bananas that need warmer climates.
Chicken coop: For your chickens.
Rabbit hutch: For your rabbits.
Kennel: For keeping many working dogs (such as herding dogs).
Silo: To store feed.
Shed: To store tools and supplies.
You would have to build barns and homes still.
Duck ponds: Fenced in pond areas could be created for ducks.
Fields: Expansive paddocks would need to be created for sheep, alpaca, and cattle.
Pig pens: Needed for pigs.
Milking stations: For milk-able animals(cows, ewes, goats).
Animal tools: A variety of tools specialized for different animals.
I don't have anything specifically in mind- I just think some new decor should be added for this to make your farm look more, well, farm-like.
And that's it for now! I have many more ideas for this that I'm formulating, so I'll likely edit/add onto this often. For now, I'd like to hear for feedback on any of this that you see so far. Criticism, suggestions, and corrections are all welcome! (Just don't be too harsh/rude on me, please! This is the very beginning layout for this idea, it's still in progress!)