Data and methodology: birth odds and life outcomes

Scope and reference date

This page describes the independent 80億分之一.com edition, checked on 23 October 2026. Its dataset contains 172 countries and regions with rounded baseline inputs around 2023. It is a game dataset, not a live statistical feed or a complete reproduction of the source datasets. About this edition.

How the country draw works

Each included country has an annual-birth weight and a population weight. The game selects one country using the chosen weights, then begins a fictional life at age zero.

• Birth mode: country births ÷ sum of births in all included countries.
• Population mode: country population ÷ sum of population in all included countries.

The current sums are 129,570,700 annual births and 8,052,840,000 people. These are totals of rounded game inputs, not precise contemporary world totals. Unlisted locations are not separate draw outcomes. Repeated draws can return the same country; the game does not rotate through countries to make the results look balanced.

For Japan, the inputs are 730,000 annual births and 124 million people: about 0.5634% in birth mode and 1.5398% in population mode. For India, 23.2 million births and 1.438 billion people give about 17.9053% and 17.8571% respectively. These are game probabilities, not a prediction about where any particular person will be born.

Why a displayed birth share can differ

The homepage distribution and birth record use a separate estimated worldwide total of 132 million annual births. Japan’s displayed global birth share is therefore about 0.5530%, while its normalized birth-mode draw probability is about 0.5634%. That global share is not the population-mode probability. The total includes a worldwide remainder that is not a separate playable country.

The homepage birth/death counters are elapsed-time estimates using fixed annual totals of 132 million births and 61.7 million deaths. They are not live observations. Shared-life statistics only summarize published game records; this self-selected sample is neither all plays nor a real population survey.

How the data inputs are used

• Population, births and fertility inform the birthplace draw and population background.
• Life expectancy and child mortality inform the simplified lifespan model.
• Income, inequality, urbanization and employment inform living conditions and work.
• Education indicators inform the background for learning opportunities.
• Homicide rates and life satisfaction inform risk and living conditions.

These inputs draw on public statistics and are simplified and rounded for the game. They are not live statistics. The dataset does not retain a source-year and provenance record for every field, or a documented per-field missing-value procedure, so it cannot support a fully reproducible statistical audit. Game values are unsuitable for research or real-world decisions requiring precise statistics.

How lifespan and events are modeled

The engine constructs a simplified age-specific mortality curve from life expectancy, under-five mortality and homicide inputs. It does not import complete official life tables. The curve is calibrated to the baseline life expectancy; annual risk is then affected by the character’s health from age five and by illness. An individual ending, and the average of simulated endings, need not match the source life expectancy.

Education, work, relationships and causes of death use authored events, game conditions and random draws. They are not individual-level statistical forecasts. Higher health may lower risk without making it zero. A long or short life is not evidence of a person’s merit.

Past and future eras

The baseline represents roughly 2023 and stays unchanged for reference years through 2026. Earlier and later years adjust health, income, education and other conditions with simplified trends. The country draw still uses the baseline birth or population weights; it does not reconstruct each era’s birth geography. Wars, policy changes and future shocks are not comprehensively modeled. Future mode is a scenario, not a forecast.

Limits, updates and corrections

One fictional life cannot describe a country, gender or social group. Game attributes are not psychological tests, income figures are not personal financial projections, and outcomes do not predict real health. Changing settings or choices changes the simulation, not real-world probabilities.

If you spot a discrepancy, send feedback with the country, indicator and source year. Read the beginner’s guide and choices guide, or start a life.