Revision 4

Overview

Aging in inZOI is automatic. Zois progress through nine life stages over a total lifespan of approximately 100 in-game days at default settings. Stage transitions happen instantly: one moment a Zoi is a child, the next they are an adolescent with a different body and new abilities. There is no visible progress bar or countdown showing how close a Zoi is to aging up. Players have several tools to control aging speed: separate toggles for player and NPC Zois, a day length slider that stretches or compresses real time, simulation speed controls, and cheat commands that freeze aging entirely or prevent death.

Life Stage Durations

Each life stage lasts a fixed number of in-game days. The total from Newborn to end of Senior is approximately 100 days, though the Senior stage has some randomness in its exact length.

Feature Unlocks by Life Stage

Each life stage introduces or restricts specific gameplay features. The table below shows what becomes available at each transition.

Create-a-Zoi Restrictions

Not all life stages are available in the Create a Zoi character editor. Three stages are locked out:

• Newborn and Toddler: These stages only occur naturally when a Zoi has a baby. Newborns age into Toddlers automatically after 1 day.

• Adolescent: This transitional stage between Child and Teenager is not selectable. Adolescents only appear when a Child ages up.

The remaining six stages (Child, Teenager, Young Adult, Adult, Middle-Aged, Senior) can be selected directly when creating a new Zoi.

Physical Appearance Changes

When a Zoi transitions between life stages, their physical appearance updates instantly. Body proportions, height, facial features, and skin texture all change in a single moment to reflect the new age bracket. Children grow taller when they become adolescents, teenagers develop more adult proportions upon becoming young adults, and seniors develop wrinkles and may show white or gray hair. There is no gradual transition; the body updates all at once. This instant change mirrors how games like The Sims handle aging up, though having nine stages (compared to fewer in many life simulators) makes each individual transition less jarring.

School System

School attendance is tied directly to life stages. Each school-age Zoi is automatically enrolled in the appropriate institution:

School schedules follow standard work hours. Zois leave home approximately 1 hour before their school day starts and return after classes end. Skipping school repeatedly can have negative consequences, similar to missing work in a career.

Aging Settings

Aging settings are found in Game Menu > Options > Simulation. Two separate toggles control aging independently:

Both settings use arrow buttons to toggle between Enabled and Disabled. These options were added in the April 4, 2025 hotfix during Early Access. Before this patch, there was no way to disable aging through normal settings. The two toggles are independent, which enables several useful strategies:

• Freeze your household, age the city: Disable aging for My Zois while keeping Other Zois enabled. Your family stays at their current stage indefinitely while the rest of the city continues to age naturally, keeping the world dynamic.

• Freeze everything: Disable both toggles to stop all aging citywide. Useful for sandbox play where you want unlimited time without any Zoi aging up or dying.

• Age only your household: Enable aging for My Zois but disable it for Other Zois. Your family progresses through life stages while neighbors remain fixed. Useful if you want to experience the full lifecycle without the city population shifting around you.

Day Length

The Length of Day setting controls how many real-world minutes equal one in-game day. It is found in the same Simulation tab as the aging toggles.

Changing day length affects all time-based systems, not just aging. Career schedules, school attendance, seasonal transitions, and need decay rates all speed up or slow down with the day length. Shorter days mean Zois age faster but also have less real time to complete daily activities like going to work or leveling skills. Longer days give more breathing room per stage but mean each activity takes proportionally longer in real time.

Simulation Speed

Separate from day length, the simulation speed can be adjusted from 1x to 4x using the controls in the bottom-left corner of the screen. Higher speeds make time pass faster within the current day length setting.

• 1x: Normal speed.

• 2x to 4x: Progressively faster; useful for waiting through work hours or sleep.

• 5x and above: Disables Zoi movement and autonomy. Only use for skipping large chunks of time.

• Pause (0): Fully pauses the simulation. Zois freeze in place and no time passes.

When all household members are asleep, the game automatically advances at 30x speed (added in v0.3.0), fast-forwarding through the night until someone wakes up.

Death from Old Age

As of the April 1, 2025 hotfix (v0.1.3), only Zois in the Senior life stage can die naturally from old age. Before this change, natural death could occur at any adult life stage based on probabilistic calculations. The developers adjusted this because they felt it was important for players to have time to bond with their characters and fully immerse themselves in their stories.

This rule applies only to natural death from aging. Non-natural deaths (fire, drowning, electrocution, starvation, sleep deprivation, car accidents, falling) can still happen at any life stage from Teenager onward. Children cannot die; if both parents die, children are sent to the Child Protection Agency.

Cheat Commands

Two cheat commands provide additional aging control. Open the console with Ctrl+Shift+C (cheats must be enabled first):

The stopAging cheat affects all Zois globally, unlike the settings toggles which separate player and NPC Zois. The immortalZoi cheat goes further by preventing all forms of death, not just age-related death. To change a specific Zoi's age directly, use the cheat console to access the age-change tool. This lets you set any playable Zoi or NPC to a different life stage, though it requires cheats to be enabled.

Current Limitations

• No per-stage duration control: You cannot customize how long each individual life stage lasts. The day length slider scales all stages proportionally.

• No age display: There is no way to check a Zoi's exact age or see a countdown to their next stage transition. The transition simply happens when the day count is reached.

• No birthday system yet: The 2026 Roadmap includes birthday celebrations and age-related events. These features are planned but not yet implemented.

• Instant transitions: Aging up is instantaneous. There is no gradual physical change; the Zoi's body updates all at once when the stage changes.

Upcoming Features

The 2026 Roadmap includes several aging-related improvements under the "Fundamentals First" initiative:

• Birthday system: Birthday celebrations and age-related events for each life stage.

• Per-family story progression: Adjustable intensity toggles for how quickly families develop.

• Childcare urges: New timed urges specifically for parents caring for young children.

• Expanded baby features: Infant strollers, changing tables, high chairs, bathtubs, and bouncers.

Tips

• If you want a long-lived Zoi without disabling aging, set the day length to the maximum (24 hours per in-game day). Each life stage will last many real-world days.

• Disable aging selectively: freeze your household while letting NPCs age. This keeps the world dynamic while giving you unlimited time with your main characters.

• Plan skill development around stage durations. Children have 7 days to max child skills. Teenagers have only 4 days before becoming Young Adults.

• The Senior stage is unpredictable. Save frequently once a Zoi reaches Senior age, as death can happen at any time.

• If you want the full lifecycle experience, start with a pregnant couple. The child will age through every stage naturally.

• Use the stopAging cheat for temporary pauses during important moments. You can re-enable aging afterward with stopAging false.