Approval

Approval is the measurement of your people's happiness. Higher Approval leads to increased productivity while low approval decreases productivity. Approval is displayed as a percentage (%) however is actually calculated in points between 0 and 100, values outside this range are truncated to fit. Approval also affects the Security of your cities, making them more or less prone to Espionage.

Cities have a base Approval of 60 which can be increased or decreased for a number of reasons, and your Empire has an overall approval rating, which is a weighted average of the approval of all cities in your empire. The way to calculate Empire approval is to take the sum of all cities' approval times their population, then divide that total by the empire population, essentially giving you the average approval of each population unit in your empire.

Penalties to Approval
Over the course of the game, various things can reduce the approval of your cities. Among them, the most common ways to reduce disapproval are by Empire Expansion Disapproval and disapproval generated by low-level Districts. Empire Expansion Disapproval is a penalty to Approval that reduces it by 10 in every city you control for each city you have past the first, and effectively serves as a way to restrict how quickly an empire can expand; you can take over a lot of regions very quickly sure, but you will probably suffer a seriously reduction in approval as a result. Similarly, the Borough Streets district that serves as the main way to grow cities incurs a -10 penalty while at level 1, making the early growth of a city reduce approval quite a bit. However, it should be noted that Borough Streets provides a bonus of 15 for each level after first, making it possible to get a net +5  from a level 2 district, which counters the disapproval generated by new districts after a certain point. The Allayi have their own district, the Garth of the Allayi, which incurs a smaller approval penalty of -5.

Beyond that, there aren't many sources of Disapproval. There are a handful of winter effects that can appear, a city's approval is reduced while under siege, and it's possible for an enemy empire to reduce the approval of your city if they have control of both Chaka and Fakir, have unlocked the Urkan Power training, and have one of the two rooted in a region next to your city. However, Approval is largely meant as a means to balance expansion and prevent empires that are particularly good at it (like the Broken Lords) from expanding too quickly.

Reducing Empire Expansion Disapproval
Because Empire Expansion Disapproval is often one of the main sources of disapproval, knowing how to counteract it is very important to growing an empire without crippling it. Two of the most direct ways to reduce expansion disapproval are with the Bread and Circuses and State-Approved Theatre technologies, which both decrease expansion disapproval by 25%, and are available in Era III and V respectively. Similarly, completing the Beloved of the People Legendary Deed in Era V will reward you with the Patriotic Propaganda technology, which further reduces expansion disapproval by 50%. Managing to get all three of these technologies will reduce expansion disapproval across your empire to 0, allowing you to expand your empire freely.

There are also a number of Hero Capacities and Skills that can reduce the expansion disapproval in a specific city, but those will be covered in the section on Heroes further down.

Districts
As mentioned before, each level 1 district reduces approval by 10, but this can be counteracted by leveling boroughs or the city center, as level 2 provides an approval bonus. Building districts in a double-wide line or in triangles helps to get level 2 bonuses efficiently. On top of this, there are a number of special districts - ones that can only be built once per city, empire, or in the world - that increase a city's approval. All of these districts have additional effects not listed here, and instead only the effect on Approval is listed.

City Improvements
This list includes any City Improvement that increases a city's Approval. Many of the improvements listed have additional effects that do not affect approval, but for simplicity those effects are not listed.

Capacities
While there are no capacities that directly increase a city's Approval, there are a couple that reduce the effects of Expansion Disapproval, though they are fairly rare.

Skills
As with the capacities, some of these skills target expansion disapproval rather than directly increasing approval.

Accessories
Only the Mithrite Tomes provide a bonus to Approval of a city when equipped on a governing hero, increasing it by a small amount for each unit garrisoned in the city.

Assimilation
The Eyeless Ones provide an assimilation bonus of +5 on Cities per pacified and rebuilt village, up to +30.

Empire Plan
Tier 2 of the Empire and Expansion branch of the Empire Plan increase the Approval of all cities by 25

Resource Boosters
One of the best ways to gain approval, Luxury Resource boosters all provide a boost to Approval while they are active. Dye, Emeralds, Gold, and Spices all provide a bonus 5 on Cities while their boosters are active in addition to their other effects, while Wine provides a bonus 30  to all cities, making it the best way to increase approval in the early game. All other luxury resources provide a bonus of 10.

Technology
As mentioned before, there are a handful of technologies that reduce expansion disapproval, but there aren't many that directly increase Approval. The only exception to this is the Necrophages' faction-exclusive technology, Demanding Gods, which they can research in Era II. This technology allows the Necrophages to sacrifice 1 in a city in order to increase the city's Approval by 30  for a number of turns equal to the population at the time the sacrifice is made, though the duration can be increased by sacrificing another.

Urkans
An empire that has control of both Chaka and Fakir will be able to unlock the Urkan Power training, which makes it so that when either Chaka or Fakir are rooted in a region next to a city, that city will get +50 if it is owned by the person who controls either or is owned by an ally of theirs, or a -50  penalty otherwise.