HEAVY construction. Please contribute if you know more.

Unrest increases when you go over your city cap, as well as through some special random events.

When the unrest bar reaches 75, you will randomly get one of the following results (taken from this forum post ): 

  • Riot. One city at random in your empire riots, giving it -50% production of all types, and +2 unrest per turn. This city is chosen from any city, including special cities. It has no effect if a special city is chosen, and limited effects on anything that isn't a resource power house city.
  • Revolt. This only happened once, three level 1 units owned by the neutral player appeared near one of my cities. I killed them with a nearby garrisoned advanced unit + city fire. It was a net gain for me since it levelled up my unit.
  • Something like 'intellectual stagnation' occurred. I've no idea what this did. Clicking the event brings up the diplomacy screen just like if you'd learned a new passive skill, but none existed there. I didn't see any research penalties or research rate penalties, so I'm not sure if this was bad or not.

Each time you fill the unrest bar, it goes down to about 25% of its maximum size, and begins to fill again.

Unrest is a negative thing. Gaining unrest, or positive modifiers, increase Unrest and Unhappiness. Decreasing unrest creates Happiness.

Unrest can be affected by:

Name Modifier Obtained by Affects Duration
Garrison Unit in City City
Bureaucrat  1 Random Loot Empire
Personal Chronist -1 Random Loot Empire
High Priest -1 Random Loot Empire
Public Opinion Manipulation -3
Public Relations -1
Charismatic  -2 Great Mage perk Empire
Destroying a Building 2 Destroying a Building City 10 Icontimer
4 Plundering a City City 10 Icontimer
-1 Looting nearby monster lair  City 10 Icontimer
Taxman 1
City Riot 2 10 Icontimer
Strong Dissatisfaction 10 Quest City 5 Icontimer
Displeasure 5 Quest City 5 Icontimer
Joy  -10 Quest City 5 Icontimer
Happiness  -5 Quest City 5 Icontimer
Nation's Displeasure 3 Empire 5 Icontimer
Nation's Happiness -1 Empire 5 Icontimer