Why we built this

The problem with how it is usually said

"Where you are born matters" is true, familiar, and useless on its own. It is said so often that it has stopped carrying information. Meanwhile the figures that would make it concrete — survival curves, conditional survival, the age distribution of deaths — sit in a UN spreadsheet that almost nobody opens.

The gap is not a lack of data. It is a lack of translation. A life table is 101 rows of probability; a person is one row drawn at random. The translation between them is arithmetic, and it is the whole idea of this site.

Why a simulation and not a chart

A chart of life expectancy by country is read once and forgotten. The same numbers experienced as one life — with an age, a place, and an end — are remembered. That is not a claim about learning outcomes; it is a design choice about what makes an abstraction stick.

The simulation is deliberately thin. It does not ask you to build a character. It draws a birth, offers a handful of decisions, and then gets out of the way while the life plays forward. The interesting object is the draw, not the player.

What we refuse to do

We do not present a simulated life as a forecast. It cannot be one: the model does not know who is playing, and a period life table is not a prediction for an individual.

We do not invent an effect size for a decision. Only options with a cited study and a stated conversion into this country's life table carry a non-zero effect; everything else moves the record and not the survival.

We do not fill a missing value with a plausible one. Where a country has no observation, the field is omitted or labelled as estimated, and the count of locations with data is published per indicator.

We do not claim a number is ours when it is not. Figures derived here carry their formula; figures from the sources carry the source and its licence, on the same page.

Where the line is

Nothing on this site is copied or adapted from another life-simulation site — not code, not text, not imagery, not the visual design. The simulation, the writing and the visual system were produced for this project. The only inbound code is the open-source framework layer, used under its own licences.

What it costs, and what it asks

Nothing, and nothing. There is no account, no payment, and no advertising. Finished lives stay in your browser. The dataset is downloadable and the whole computation runs client-side, so the site can be read and checked without trusting us.

Where it falls short

The model is a period model: one year's death rates applied across a life. Children born after 2023 borrow the 2023 table. Migration inside a country is not modelled, so urban and rural are set at birth and do not change with the decisions. Income is a scale derived from national accounts and a quintile, not a household survey. Each of these is stated on the methodology page with its direction of error.

What we hope happens

That a reader plays one life, sees an age at death they did not choose, opens the country page behind it, finds the formula, and checks a number against the UN's own table. That is the entire ambition. If the site is quoted, we would rather it be quoted for the arithmetic than for the premise.

Now live one

The odds on this page describe populations. The game draws one birth and plays that life forward, year by year, from the same tables.