Life stage

A life stage is the age of a Sim. Sims do not age continuously, day by day, year by year, but all at once, "jumping" to the next stage in life.

The Sims
In The Sims, there are only three stages: baby, child and adult.

Babies grow into children after 72 hours. Children do not grow up into adults, although the Makin' Magic expansion allows magical children to grow up by using the Age of Instant charm. There are third-party programs which can grow a child into an adult. There are also hacked objects which can allow a child to function as an adult — or vice versa.

The Sims 2
There are seven life stages in The Sims 2.
 * Baby: (3 days)
 * Toddler: (4 days)
 * Child: (8 days)
 * Teen: (up to 15 days) Note: Teens can grow up early in order to go to University.
 * Young adult: (varies; usually 24 days) University only.
 * Adult: (29 days)
 * Elder: (varies; 9–31 days) Sims who have higher aspiration levels when aging generally get more time, but there is a random element. Followed by death.

Note: The durations of life stages stated here are subject to two caveats. The first is that the  cheat suspends aging for all Sims. The second is that, from Teen onwards, Sims can use the Elixir of Life reward object to prolong life by 3 days (if successful) or shorten it by 3 days (if unsuccessful). Drinking from the cowplant will also prolong life for five days. A successful Give Me A Long Life wish will prolong life for four days.

Sims that are teens or older can become zombies or vampires, which also stops them from aging. Nevertheless, teen-vampires or teen-zombies can age by going to university. This action will change their age to "Young adult", and graduating will change it to "Adult", just like "normal" Sims. Also, PlantSims have only three of the seven life stages: toddler, adult and elder.

If a residential lot originally built in a college sub-neighborhood is placed in the Lots and Houses bin, and then in a non-college area, its aging controller may remain stuck. Sims moved into such a lot will not age until they are moved into a lot with a working aging controller. The aging controller can be unstuck by moving the Sims out, making a Build mode edit that changes the way the lot appears in the neighborhood view, and moving the Sims back in.

When a Sim is within one Sim day of transitioning from one age to another, it's their "Birthday", and they can then either wait for 6pm when they will automatically grow up, or players can trigger the age transition themselves with the "Grow Up" self-interaction, or the birthday cake. When using the cake, babies and toddlers depend on a teen, adult or elder to bring them to it. Furthermore, babies don't have the "Grow Up" interaction - they always need the assistance of an older Sim to become a toddler, no matter what. Using the "Grow Up" interaction will cause the selected Sim to grow up a day early.

The Sims 3
In The Sims 3, the toddler stage is 3 days longer, while the child and teen stages are both 1 day shorter. In addition, elders will always live for a minimum of 16 days.

There are seven life stages in The Sims 3.

With patch 22, a new option enables players to adjust lifespan for each life stage. Some life states have a lifespan multiplier that extends the ages in young adult and adult stages. For example, vampires have 5x multiplier, which extends a Sim's age in young adult to 105 days in Normal setting or 1125 days in Epic setting.

It is also possible to use a birthday cake to age up Sims. However, a Sim can only be aged up once per age. Players can also use the testingcheatsenabled true cheat, then shift+click a Sim, then click "trigger age transition". Players can do this as many times as they want, but doing this with elder Sims will kill them.

The Sims Medieval
As in The Sims, there are only 3 life stages in The Sims Medieval, baby, child, and adult. The player cannot create children or babies, only Hero Sims, who can only be adults. While the "Age modifier" can be used to make a Hero Sim appear older, technically the Sims are still adults. Female Sims with this appearance can still be impregnated.

In a recent patch, the "Child Succession" feature was added, If a hero Sim who had one or more children dies, then the new hero select menu will have the option to choose "Child Succession". This will make the child Sim the new hero, as a controllable adult Sim.

The Sims 4
The Sims 4 has six life stages: baby, child, teen, young adult, adult, and elder. Unlike The Sims 2 and The Sims 3, The Sims 4 omits the toddler life stage completely.

Étapes de la vie