# Example: a large shared city

A technical example of how the Endless Mind model described in [DESIGN.md](../DESIGN.md) handles a large, busy world with vehicles, many visitors and fast movement. No realm like this has been built: it is a sketch of how the present model would be used and where it runs out. All names here are invented for this example. Anything built with Endless Mind should be the builder's own original work (see "Original work only" in the design).

## One realm, refereed in one place

- The city ("Harborlight" in this example) is one realm. Its rules hold the map, traffic signals, time of day, vehicles, traffic and passers-by, all as state, and run on its referee.
- Visitors send only moves ("steer left", "brake", "enter shop"). The rules decide what happens, so a modified portal cannot drive faster or carry more than the rules allow.
- Vehicles are realm state. Who is driving which vehicle, who owns it, and whether a parked one may be taken are all the city's rules.
- Each visitor gets only their share of the city in their view: the nearby streets, not the whole map.

## Money and records

- Currency is a balance in the city's state, shown to each visitor in their view.
- A visitor's standing in the city (good standing, bans) is also city state. Neither can be carried to another realm: nothing crosses realms.

## What limits it today

- **One referee carries everything.** A home connection can serve tens of visitors, not a whole city's worth. Splitting a city across several referees would need realms inside realms, which the reference portal does not have.
- **Fast movement waits on the referee.** Every move goes to the referee and back through a relay, so steering feels as fast as that round trip.
- **The referee must stay up.** A busy city needs an always-on machine running the host program with its key, not a browser tab.