Crime

Crime in Microlandia is a spatial feedback loop, not a flat city-wide rate. Each 20 m block carries a dynamic attractiveness score that decays a little each day, leaks a fraction to its four neighbors, and gets a small boost whenever a crime actually happens there.

A recorded crime increases the chance that later attempts select the same area. The field loses 5% of its remaining strength each day and spreads some to neighboring blocks. Without new crimes, its total strength roughly halves in two weeks; it does not disappear at that point. This field weights where attempts happen. It does not create more offenders or give an offender extra attempts.

Where criminals come from

Criminals are not parachuted in. They come from your own population. Once a month, the city scans two groups:

• Adults of working age (eighteen to retirement age) who are not in school or university, and whose household cash cannot cover a month of basic needs. Whether they have a job or not does not matter. A working citizen whose pay cannot cover food and rent is just as eligible as an unemployed one. If they roll, they walk off the job and pick up crime.
• Unschooled teens between thirteen and eighteen who are out of school and without work.

Candidates in either group must have insufficient household cash. An adult who qualifies for unemployment benefits is exempt while the benefit is enabled. The default recruitment chance is 1.5% per year, converted to a monthly chance of about 0.126%; scenario multipliers can change it. Unemployment, homelessness, dropout rates, and household balance all feed the size of this candidate pool before the dice are even thrown.

Criminal careers can end

Each month, active offenders have a chance to stop. That chance rises with age; retirement also ends an active career. A person who stops can look for work again, but their record remains. A career cannot end and restart in the same monthly pass.

The annual desistance probabilities are simulation assumptions, converted to monthly chances. They are separate from recruitment:

Retirement ends the career regardless of that month’s roll. Better household finances reduce new recruitment but do not instantly remove existing offenders.

Police and response

A completed station needs actual employees before it protects anyone. Staffed stations protect nearby buildings and completed street tiles within a combined horizontal-plus-vertical distance of 240 m from the station. This immediate coverage updates every day, including newly built streets and homes.

Officers split their time between patrol and dispatch. Patrol units (two officers per unit) walk a fixed distance each shift. Longer routes are cached, but staffing and map changes invalidate them. One station recalculates routes per day; stations waiting their turn retain their current immediate coverage, not obsolete routes.

When a crime happens, the nearest reachable station with a response pair available answers it. Each pair handles one call per day, whether or not it makes an arrest. A five-officer station has two officers assigned to patrol and three to response, enough for one response pair. An unreachable or exhausted station cannot lend its capacity to another station. Street incidents need a street route too; officers can finish a park response on foot from its perimeter.

An arrest removes the offender from the active population and creates a prison sentence. An available local bed means monthly housing expenses for the remaining sentence. Without a local bed, the city records the full exported sentence cost plus transport as a payable, settled through its monthly expenses. A short sentence costs less, but it is not free: exported petty theft currently creates a $15,750 bill, including transport.

An answered incident gets a crime-specific arrest roll: 9.3% for car theft and 52% for homicide, for example. These parameters use published clearance rates as a simulation approximation. They are not a guarantee that every crime receives a response or that a nearby station will solve it. Patrol coverage prevents an attempt before this roll.

This page also lists the monthly police officer salary. That bill lands whether your stations are catching criminals or sitting idle.

Building a prison

Without a free local prison bed, an arrested offender is exported. The full sentence becomes a bill at once, instead of being spread over the sentence. That bill enters the monthly expense settlement; it is not an immediate cash transfer on the day of arrest. At current rates, exporting a homicide sentence creates an $840,600 payable for 17.8 years of housing plus transport.

A city-owned prison flips this. Inmates housed locally accrue at the lower local annual rate, billed monthly across the sentence, with no transport fee. A completed prison has 1,000 beds; once they fill, new arrests overflow back to the exported rate.

The tradeoff is up-front cash and zoning. Building a prison is a major capital decision, and it carries a sizable NIMBY footprint, so site it well away from residential neighborhoods or watch nearby approval and rent both sag. Whether the lower housing rate repays construction depends on occupancy and time. The immediate financial benefit is spreading long sentences across monthly expenses instead of booking the full exported bill at arrest.

Why crime moves families

A victim household receives a crime-related reason to consider leaving. The household’s monthly migration decision combines that reason with its savings and mobility. It must be able to afford the move. The current departure decision uses the same crime-related push for all crime types; severe crimes do not automatically evict a family.

Reading recovery

The city crime rate counts monthly incidents per 100,000 residents. The crime map counts incidents within 20 m of a building’s center over today and the preceding 30 days. Safety approval asks whether a home had any incident within 80 m during that window. These measure recent harm, so even a solved incident remains recorded until it ages out. Better patrol coverage can stop new incidents immediately while safety takes about a month to recover.

Improving household finances prevents new recruitment; it does not instantly end existing criminal careers. Existing offenders can attempt a crime each day until caught, retired or desisted. They skip attempts while their personal cash exceeds $1 million; that pause does not clear their criminal status. Every eligible offender is considered, with daily shuffled ordering so the same residents do not always get the first response slots.

Private security legalizes companies hiring guards when theft losses justify their wages. A firm must also be able to afford the hire and fill the job. One hired guard can deter petty theft (45%), burglary (35%) and store robbery (20%) at that workplace. The law does not protect parked cars or stop violent street crime. A prison changes where arrested offenders serve their sentences and how the city pays; it does not increase patrol coverage or arrest chances.

Your levers

• Build more police stations and hire enough officers to actually cover the map.
• Cut the offender pipeline upstream. School enrollment excludes students from recruitment; jobs, income support and affordable housing help households cover their monthly needs. A job or shelter bed alone does not exempt a cash-starved adult.
• Accept that prevention is cheaper than clearance. The full incarceration bill plus the rent loss from a fleeing renter tend to dwarf the cost of avoiding the crime in the first place.

Parameters

Vandalism fine amount

$300

Fine charged when police catch a vandal. Matches typical municipal fine for vandalism.

⚠️ Source pending

Vandalism repair cost

$300

Cost to repair public infrastructure damaged by vandalism.

⚠️ Source pending

Clearance rates by crime

Published clearance rates by crime type, used as arrest probabilities after a reachable police pair answers an incident. Unanswered incidents do not get an arrest roll; patrol prevention happens before an incident is recorded.

Source: FBI Crime in the Nation (2023)

Guard deterrence by crime

Probability a private security guard deters a crime attempted at the building it guards, by type. Applied only to the building-targeted theft crimes a company guard realistically affects (petty theft, burglary, store robbery), which are also the crimes that drain a company’s till; other types are 0. Grounded in field studies showing visible guards cut retail theft ~30-50% with a weaker effect on impulsive/violent crime.

Source: Retail/BID private-security field studies; Zimmerman (2014), IRLE

Distance patroled by police officers per shift

5000

The distance a police unit (2 officers) can effectively patrol during a single shift (8 hours). This affects the area that is covered daily by each police station in the city.

Source: ICMA Center for Public Safety Management

Attractiveness decay rate

0.05

Daily decay rate (ω) for the dynamic crime attractiveness field. The game uses 5% per day, giving total field strength a half-life of about 14 days without new crimes. Decay is separate from diffusion between 20 m blocks.

Source: Short, M.B. et al. (2008). A statistical model of criminal behavior

Attractiveness diffusion

0.1

Fraction (η) of each 20 m block’s dynamic attractiveness shared among its four cardinal neighbors daily. This changes where subsequent attempts are directed.

Source: Short, M.B. et al. (2008). A statistical model of criminal behavior

Attractiveness crime boost

0.5

Boost (θ) added to a 20 m block’s dynamic attractiveness per recorded crime, including solved crimes. This increases the block’s target weight without creating offenders or extra daily attempts.

Source: Short, M.B. et al. (2008). A statistical model of criminal behavior

Inmate export transport cost

$4,000

The logistical cost of transporting a criminal to an out-of-city facility when no local jail is available. Covers private extradition contractor fees, or the overtime, mileage, and processing fees for two sworn deputies to perform a long-distance transport.

Source: Police1 - The Hidden Costs of Inmate Transport

Inmate housing cost per inmate

$47,000

Annual incarceration cost per inmate when housed OUT OF JURISDICTION (no local Prison, or local Prison full). The full housing bill is recorded as a payable at arrest, equal to this rate multiplied by the sentence length in SENTENCE_YEARS_BY_CRIME, and settled through monthly city expenses. Transport is a separate addition. Reflects the marked-up contract rate other counties charge to take in inmates, on top of housing, personnel, food, and healthcare.

Source: Vera Institute

Local inmate housing cost per inmate

$32,000

Annual incarceration cost per inmate when housed in a city-owned Prison with free capacity. Lower than INMATE_HOUSING_COST_PER_INMATE because the city pays its own operating cost rather than another jurisdiction’s contract rate, and no inmate transport is needed. Vera’s nationwide local-jail operating cost averages ~$33k/inmate/year.

Source: Vera Institute — The Price of Jails

Sentence years by crime

Sentence duration used by the simulation, by crime type. Exported sentences create a full-term housing payable plus transport at arrest; local sentences occupy a bed and incur monthly housing expenses until release.

Source: Bureau of Justice Statistics — Time Served in State Prison, 2018

Police officer monthly

$9,500

The monthly salary paid to each police officer, including benefits overhead. NYPD FY25 Personnel Services budget of $5.38B across ~48,844 employees = ~$110k/year per employee. We use $9,500/month ($114k/year) to approximate total compensation including benefits.

Source: NYC Council: NYPD Fiscal 2025 Preliminary Plan (March 2024)

Prison construction cost

$75,000,000

Upfront construction cost of a 200-bed city Prison. Anchored to Monroe County, Indiana’s planned 400-bed facility ($80.9M hard construction, ~$202k/bed), scaling down to 200 beds gives ~$40M hard, ~$48M with soft costs. We round up to $75M to cover the higher-end of contemporary US per-bed estimates ($286k–$550k/bed for state projects) without inflating to the police-headquarters tier.

Source: Monroe County (Indiana) Council jail budget reporting