Adult

$$Adult is a life stage in The Sims, The Sims 2 and The Sims 3. It is the longest life stage in a Sim's life. In The Sims it is the last life stage before death, while in The Sims 2 and The Sims 3 it is proceeded by the elder life stage.

In this stage, Sims can take up full-time careers, fall in love, get married, give birth to or adopt and raise children. In The Sims they are the only sims who can prepare food. Obviously, it is nearly impossible for a family to function without adults.

Adult Sims can use most of the objects in the game and most of the interactions with other Sims.

In The Sims, being an adult is permanent and children do not become adults without spells or mods. While adult Sims can die if something kills them, they never age, so they have indefinite lifespans.

In The Sims 2, the adult stage is the longest and most important life stage. It is preceded by the teen life stage or young adult stage from The Sims 2: University. It is the only life stage in which a Sim can get pregnant and get a normal job. In the FreeTime expansion pack, a Sim can study up on parenting via the book case.

In The Sims 3 the adult stage is no longer the default age. Young adult is now the default age in Create a Sim. Adults in The Sims 3 can be considered more like adults in their 'Middle-age'. They get a few wrinkles, but they aren't as pronounced as they are in the elder stage. There's not much difference between an adult and young adult; they can still get married and have children, they have the same 5 traits they had before. However, young adults are more fertile, which means it takes less tries to get a young adult Sim pregnant.