The Sims 2
In The Sims 2, Sims can initiate the adoption of a child over the phone by calling the "Adoption Center" under the Service menu, but only if the Social Worker has not taken one of their kids. The household must have at least §3,000 on hand (though adoption itself is free from charge) and below 8 Sims or 10 household members (including pets and roommate).
When the adoption approval succeeds, the Social Worker will bring the new child the next day at 10 AM. To make sure someone is there to receive the child, it's best to call the day before a Sim's day off. The player gets to decide if the Sims adopt a baby, a toddler, or a child. Unless the baby who is being adopted was taken away from another household, the player will be able to name them. Children and toddlers will always come pre-named. If any children have been taken by the social worker in that neighbourhood, they will be first-in-line for adoption. If the Social Worker has taken their children, the Sims will not be able to adopt. Other Sims in the household can adopt, however.
The Sims 3
In The Sims 3, the social worker will arrive immediately but will opt to come back later if there are no adult or elder Sims on the lot. The player will be asked to pick the age and gender of the adoptee. Unless the adoptee was taken away from another household, the player will also get to pick his or her name.
In both The Sims 2 and The Sims 3 an adopted child will have the last name of the Sim who made the call. However, it has been reported that, on rare occasions, the adopted baby/toddler/child will have another last name.
Families will not be allowed to adopt a child at all if the Social Worker has previously taken away a child in their household.
Children in The Sims 2 who have been taken away from a family by a social worker are first in line to be adopted by another family. Of course, the adopting family will have to select that child's age.
When a child that was taken away from another family is adopted, their old parents and siblings will remain known to them but only as friends. Also, their memories will be erased. However, on rare occasions the adopted child will keep their old family tree and will not be related to their new adopted family.
This cannot be done in The Sims 3.
When planning to have Sims adopt a pet, players should remember that each pet will take up a family slot. In Unleashed, a lot can only have a total of eight pets or Sims in one house. In The Sims 2: Pets, a lot can have a total of ten Sims and pets, but no more than eight Sims and no more than six pets.
The Sims: Unleashed
In The Sims: Unleashed, pets can be adopted on community lots in Old Town that have the Frisky Feline Promo Pen and/or the Fluffy Puppy Pet Bin. By default, these displays can be found in Pet Paradise, at 70 Elm Street. Adopting a pet costs §399. Players will be able to choose the gender of the pet, and to select from a number of breeds, but the pet will have a random personality. Players can use custom pet skins, but a pet cannot be customized once it has been selected.
For a Sim to be able to adopt a pet in Unleashed, the player must use the "Explore Old Town" option to call the cab to Old Town. If the Sim took a date to Old Town, the option to adopt will not appear.
Sims can also befriend and adopt strays that wander onto their lot.
The Sims 2: Pets
In The Sims 2: Pets, Sims can call the pet adoption service and adopt a kitten or puppy, or an adult cat or dog. If the call was made before 10 AM, the pet will arrive that day, otherwise it will arrive at 10 AM the next day. Sims can adopt adult cats and dogs on community lots that have the Cat-Crazy Pet Display and/or Doggonit Pet Display. Players can use one of the premade pet shops in the Lots and Houses bin, or can build their own. These displays allow players to access a streamlined version of Create a Pet. Unlike the version in CAS, this one does not allow players to select collars, and can create both cats and dogs. So, regardless of whether a display shows a cat or a dog, the player will be able to create either species. The base fee for adoption is §399, but it may be higher if the pet has learned any behaviors or commands. Unlike The Sims: Unleashed, a family can adopt a pet from a pet shop even if only one member travels to the shop.
Players who want to simulate a free adoption of an adult or elder pet can go into CAS, create a cat or dog, and merge it into an existing (non-University) household.
Sims can befriend and adopt strays that wander onto their lot.
Players should note that playable Sims autonomously visiting a pet shop may autonomously adopt a pet. The next time that Sim's household is played, the player will be notified of this, and given the opportunity to accept or reject the adoption. A mod from More Awesome Than You will prevent autonomous pet adoptions.
The Sims 3: Pets
Pets can be either adopted or given up for adoption. The option to give up a pet for adoption can be found on Sims' computers, laptops and cell phones. Sims can also call the adoption service via a computer or cell phone in order to adopt a pet. The player is able to choose to either adopt a neighborhood pet given up for adoption, or one from the pet shop. When adopting from the pet shop, a list will show up. It will show various pets categorized by species, and will have information about their life stages and traits.
After choosing the desired pet, a randomly generated NPC will arrive and deliver the pet to its new home. If the Sim neglects the pet, the adoption service will come back to remove it from the owners.