Lifecycle and aging

Owns each agent's age (or an age-structured population count) and a table of life stages with durations, capabilities, needs, and mortality. Each tick age advances; crossing a stage boundary changes what the agent can do (work, marry, study), what it needs, and how it looks; mortality rises with age until death. Births add agents through reproduction rules. The Sims 2 has seven stages (baby, toddler, child, teen, young adult with University, adult, elder): babies become toddlers after 3 Sim days, children become teens after 8, teens live 15 days, adults become elders after 29, and elder lifespan depends on the aspiration meter. Victoria 3 aggregates the same idea: natural growth is birth rate minus mortality, both falling as standard of living rises. Inputs: time, health, birth rules. Outputs: workforce and dependents, deaths, succession and inheritance triggers.

Time becomes personal: the player watches characters grow up and grow old, plans careers and heirs, and grieves. Aging turns a static roster into a pipeline in which the player raises the next generation of workers.

• number and duration of life stages relative to the game calendar
• capabilities and needs per stage, such as child labor rules or elder frailty
• mortality curve and whether death is fixed-age or probabilistic
• birth rules and fertility windows
• player controls such as aging toggles and lifespan settings

• Lifespans short relative to play pace make characters die before players attach, so games add lifespan settings or aging toggles.
• Demographic echoes: one founding cohort ages together and causes a labor collapse or mass death decades later.
• Children are pure cost with nothing to do, so players avoid births.

• Age structure sets dependency ratios that throttle labor and drive housing and school demand.
• Founding cohorts create waves of births, retirements, and deaths that repeat across generations.
• Deaths trigger inheritance, succession, and grief, coupling lifecycle to social and dynastic systems.

• Can generative models keep a character recognizable across ages in appearance and personality while allowing growth?
• What ratio of lifespan to play pace maximizes attachment and generational play?