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. Children and adults have indefinite lifespans, and cannot die via aging.

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: With University, Teens can grow up early in order to go to college.
 * Young adult: (varies; usually 24 days) University only. Lasts until the Sim leaves the college sub-neighborhood.
 * Adult: (29 days)
 * Elder: (varies; range is 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 6 pm 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.

As a household's game clock only runs when it is being played, each household's game clock runs independently from all others. Sims will not age, much less age up, automatically unless they are part of the household being played. This also means a playable Sim will not die off-screen.

The Sims 3
In The Sims 3, by default, all households in the neighbourhood observe the same game clock. This means that Sims not part of the active household but are due to age up will do so off-screen.

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 at anytime. 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 seven life stages: baby, toddler, child, teen, young adult, adult, and elder. Unlike The Sims 2 and The Sims 3, The Sims 4 initially did not have the toddler life stage, it was added in with the January 12, 2017, patch.

All played Sims who are not in the active household will age automatically off-screen unless Auto-age is switched off or to 'Only Active Household'.

Occasionally, a Sim may get an invitation over the phone from another Sim living in a different household to attend their birthday party which can be up to several days before the latter Sim is actually due to age up. The former Sim may decline and the latter Sim will age up at the time (s)he is due to do so.

Pregnancy will affect a Sims lifespan as they do not age until given birth.

When an elder's age meter gets filled up completely, it may take up to 48 hours for that elder to pass away. Elder Sims who have the "Active" or "Long Lived" traits will get additional time. Extra time can also be obtained with Cowplant essence.

Patch 50 expanded the young adult and adult lifespans by 4 days each to accommodate the addition of toddlers.

The Sims FreePlay
The Sims FreePlay has 6 stages. They are Infant, Toddler, Preteen, Teen, Adult, and Senior..

Étapes de la vie   Levensfase