City incidents

Incidents such as fire, riots and illness, might happen at any moment, endangering the stability and order in a player's empire. The chances and frequency of them happening, depend on several factors. It is not possible to completely turn off incidents but difficulty settings can adjust the probability of them happening. Incidents can die down on their own after a period of time, but players can deal with them faster, prevent the damage done and keep them from spreading by building emergency services.

## Fire

Almost all buildings can catch fire. Both residential districts and production buildings are vulnerable. Burning buildings slowly lose their hitpoints until the health bar reaches zero and the building collapses into ruins.

Fire can start in residences at any time. Dense city areas are more likely to start burning and fire spreads faster when buildings are very close to each other.

Production buildings have different chances of catching fire depending on the type of the building. The chance increases with high productivity and harsh working conditions as it makes accidents more likely to happen. This problem can be especially severe when using electricity, as this heightens productivity.

### Explosions

Factories which use heavy machinery or chemicals (like  Schnapps Distillery or  Dynamite Factory) can accidentally blow up. An Explosion turns a building into ruins instantly and can set nearby buildings on fire. Buildings also have a much higher chance of exploding while on fire.

## Riots

An unhappy population can revolt against a player's leadership and organise riots. Rioting people will stop working and paying taxes. Riots start within buildings, but when they're left unchecked for long enough, the people might start forming into mobs that travel the streets and encourage even more people and buildings to join their strike. During larger strikes, the rioting will start to damage or set fire to structures. Should the amount of riots and mobs in the street manage to get out of control, this can lead to a very destructive situation that greatly decreases the player's available workforce and income.

Riots can affect both residential and production areas. In residential districts riots are caused by the general level of happiness. In production buildings, working conditions have the biggest impact. Continuous use of propaganda can also anger a population into rioting.

It's worth noting that settlements in  The Arctic cannot riot. The population there does not have Luxury Needs, a happiness rating, or the ability to change the working conditions on their production buildings. People there are just happy to survive the biting cold and have an awareness that tearing down their own settlement is detrimental to the overriding desire not to freeze to death.

## Illness

A player's people can sometimes fall ill, with the disease potentially spreading into an epidemic. The chances of getting ill increase when people work hard and live close to polluting industries. Not satisfying the population's demands for all the goods they desire, can also increase the chance of Illness. Illness appears only in residential districts, not in factories. It can spread very quickly and can even jump to other islands by ships carrying it over between Trading Ports.

Illness prevents a residence from paying its taxes and will slowly lower the amount of people living within, rather than damage the building itself. If illnesses are left unchecked and given a chance to ravage the affected residences past a certain threshold however, these houses might be abandoned into dilapidated ruins. Nobody will want to live in a place where the taint of death has managed to seep into the walls and floors.

### The Arctic Flu

A special, more contagious type of illness originates from  The Arctic, called the *Arctic Flu*. Arctic settlements don't have Luxury Needs, but a need for Heat - a desire to stay warm - instead. When a player's Arctic settlements are properly governed, the Arctic Flu is an occasional, but manageable incident in this region. Should a player fail to keep their Arctic Settlements warm however, the Arctic Flu quickly becomes a virulent and constant presence, with a potential to grind productivity and growth to a halt.

It is unknown whether the Arctic Flu can travel to Old World or New World.

## Emergency Services

A player can counter and prevent city incidents with Public Buildings that offer emergency services. These include  Fire Stations,  Police Stations,  Hospitals and  Ranger Stations. Each of these will send out specialized units that travel the streets and actively combat an incident wherever one transpires. Fire stations send out firefighters to extinguish burning buildings, police stations send out police officers to pacify protesters and hospitals send out doctors to cure sick people. Arctic Ranger Stations send out units that double as both fire brigade and doctor.

Emergency services also passively lower the chance of an incident happening in buildings nearby them. With enough Fire Stations for example, the chances of fire and explosions happening in the adjacent dynamite factory can be reduced or outright nullified.

A player should build all three emergency services in residential areas, but production districts need only fire and police stations.

Every Emergency Service has its own influence range which spreads out along adjacent streets, depending on the quality of those streets. Paved streets increase the effective range of all emergency services and it's advisable to pave in highly endangered areas. All emergency services have a limited number of units that can be sent out to fight the incidents. If the population is happy, three additional units can be mobilized:

* 1 unit if happiness value is +10 or higher
* 2 units if happiness value is +30 or higher
* 3 units if happiness value is +50 or higher

## Unlock conditions of the incidents

Incidents can occur only on islands with enough population if a global unlock condition has also been achieved. Every incident has different unlock conditions in each region - a global condition has to be met only once and can be achieved globally, while a local condition has to be achieved locally on every island and can be reset by decreasing the amount of population again.

For example, unlocking illness in the Old World (and Cape Trelawney) requires having 1500  Artisans globally and at least 1 artisan locally. The local conditions also include achieving any amount of population of tiers higher than the tier the condition requires. Therefore having any amounts of engineers, investors, scholars or tourists can also unlock illness on an island, even when no artisans live on the island. However, the presence of tourists does not unlock riots or explosions. When global population has never been higher than 1500 artisans, illness can never occur in the Old World even if local population on some islands meets the local requirement. When the global requirement has been reached though, the local population still needs to be above the local unlock condition to allow an incident to occur. Therefore even when being past the stage of 1500 artisans, islands with only farmers or workers would never experience any illnesses.

It is important to mention that transferring workforce between multiple islands and establishing a commuter network can unlock incidents on islands even when their local population does not meet the unlock condition. If one of the islands within the commuter network has enough population living on it and an incident is unlocked there, the incident also becomes unlocked on all other islands within the commuter network. But when none of the islands has enough population, the incident cannot occur on any of the islands in the network.

The table below lists all global and local unlock conditions for every incident type and for each region.

## References

1. ↑ 1.0 1.1 https://www.anno-union.com/en/beware-incidents-are-coming/