Updated for 2018 June. Feel free to add things up! 1. Introduction Happiness is a much recurrent issue for old and new players, especially after the changes done in 2018 March where happiness is scarce, so I'll try to make a comprehensive guide on how it works and discussing strategies. 2. Effects of happiness Why is happiness so important? Check this: - Local happiness has no effect, only global happiness matters. - Local unhappiness cannot be greater than city population (they are your citizens who are unhappy). - Every positive happiness point adds to golden age points. - Unhappiness adds to combat penalties (capped at -20% CS). - Under 10 unhapiness. Cities can no longer be settled. - Under 20 unhappiness. The empire is under revolt. Rebel units may appear and cities can be lost. - There is a global efficiency bonus that affects and growth, and values: +(Global happiness)%, capped at -10 and 10. 3. Sources of happiness Happiness can be obtained in several ways. - Difficulty handicaps. - Having access to luxuries. Expending great admirals in voyages grants some luxuries, making allies with some city states too. - Discovering world wonders. - Social policies. - Religious beliefs. - Luxury monopolies. - Allied mercantile city states. - City state quests. - Expending Great Musicians for Concert Tours. - Happiness buildings such as Zoo, (Circus line). Unhappiness is gathered by: - City needs. - Religious unrest. - Isolationism. - Specialists. - War weariness. - Conquered cities - Ideologies 4. Further explanation of happiness sources I'll discuss only the sources that present some complexity in the following points. 4.1 Luxuries A player can have access to a luxury either by controlling it directly with a valid improvement (its own, a great person tile improvement, or a unique improvement that allows for connection), by trading for it, by allying a city state that has an unique luxury, or by expending Great Admirals in Discovery Voyages. The effect of luxuries scales for the average population size of your cities. This means that every accesible luxury gives more happiness when cities are tall, but on the other hand, tall empires have usually access to fewer luxuries. 4.2 Needs Your people are jealous. They expect a certain quality of life from what they gather from the rest of the world and become unhappy when the player cannot provide. Yields considered are gold (poverty), science (literacy), culture (boredom) and city defense (crime) (As of June 2018 betas, city defense is replaced by distress, accounting for food+production in the city). Best thing in improving city needs is providing more yields. Other than that, it is also posible to reduce needs with some social policies and some buildings such as the barracks. City defense is increased by buildings such as the walls, and by placing garrisons and great generals in the city. Fealty scaler is also a good source of city defense. (Deprecated) Technically, every city wants to be over the median value of the world-wide city yield per population. More explicitly, divide all yields by the population in each city and find the middle value for each yield. A penalty is then applied for the number of technologies the player has researched. Finally, the number of people suffering from some city need is obtained from the distance of the current city yield per population to the target value. In other words, your citizens have to be efficient. Having workers on +2 food tiles is not efficient at all. 4.3 Religious unrest Your citizens dislike people not following the majority religion in the city. This is obtained by the relative number of people that do not follow the majority religion. 4.4 War weariness War weariness happens as a result of a prolonged or bloody war. Its effect takes a while to be noticeable, but it also takes longer to go away. 4.5 Conquered cities. After a city has been conquered it can stay as a puppet or be directly controlled. As a puppet it produces one fixed unhappines per 4 pops in the city (actual figures may vary). As a controlled city without a courthouse, it produces one unhappiness for every pop in the city. With a courthouse, unhappines is the same as in any other of your cities. Razing a city does not increase unhappiness, but makes the city revolt and might produce rebels. 4.6 Isolationism. Missing a connection with the capital makes your people sad. A connection can be made by trade routes alone, by uninterrupted land roads, or by unblockaded coastal cities with lighthouses. Beware that trade routes may use better destinations, roads cost big gold maintenance, while lighthouses pay for themselves but are not prioritary. 4.7 Specialists Every 5 worked specialists 1 unhappiness is added globally (again, it may vary for every release). On the other hand, specialists provide yields that are hard to find in the field, such as science and culture, so they are useful for addressing unhappiness from needs. 4.8 Ideology When your people are influenced by another civilization, and said civilization has a diferent ideology than your people, then they become unhappy. This penalty starts applying 30 (??) turns after you have obtained an ideology. Switching your ideology to the one that has influenced your people removes the penalty. 5. Strategies. When a city is suffering from one kind of unhappiness, the obvious thing to do is trying to increase the yields of the same kind, and finding out bonuses against the related unhappiness type. For increasing those yields there are buildings, world wonders, some improvements, specialists, policies, and technologies throughout the game (not going to make a full list now), and the same is true for reduction needs bonuses. It's worth noting that world wonders are always kept upon capturing a city, so if a wonder that reduces a kind of unhappiness that is hurting your empire is already built by other civ, capturing the city where that wonder is built may help. The following are less evident strategies. 5.1. Controlling growth and tech progression. Since a major factor of unhappiness comes from needs, it's important to have them under control. Every city pop that is not working on a over-the-average tile is probably contributing to unhappiness. So, when no good tiles of specialist slots are available, it is preferably to work on fewer food tiles since it slows down city growth. Food buildings are still useful, for they release your workers so they can work on more productive places. If the unhappiness is too big in one city, but it is fine in the other ones, then controlling growth in that city is enough. But when unhappiness is too big in most cities, then it is infrastructure what is missing. This happens when the player researched too fast, and the new buildings were not built. In this case, it's preferably to unfocus science for a while, until economy follows. A key for having always a nice tile to work on, is having enough worker units. The default is one worker unit per city, except for enhanced workers (Pyramids, Progress), which can do with 3 workers every 4 cities. Disclaimer: A civ might suffer from undergrowth too. Without enough population, raw yields are low, so techs and policies come slowlier than the average. Techs and policies that are needed to obtain those over-the-average tiles that make your civ happy. 5.2 Diversify. Having all trade routes departing from the same city is very effective for gold revenue, but it makes secondary cities suffer. Those trade routes give gold, science and culture to the city, helping with most city needs. Yields also need to be diverse. Production is always nice as it allows to build fast, but if production comes at the price of not having gold, science or culture, then happiness suffers. 5.3 Villages. Looking for farm adjacencies, it is easy to overlook village placement. Villages are one of the few culture sources, but also give gold and production, so they are key for handling city happiness. Villages and Towns are enhanced by being under a uninterrupted road/railroad which connects two cities, and also for passing by trade routes, so it should be mandatory to place them in such places. 5.4 Unify religion. Religious unrest can be avoided in two ways, or just be accepted. One way is to spread your religion far far away, so any religious contest is done outside of your borders. The other way is to strenghten your religious pressure so any foreign religion cannot penetrate (temples, religious buildings and garrisoned inquisitors). Alternatively, if nothing can be done to prevent a religious clash, then Pagodas and Rationalism policies help reducing religious unrest. Note that you can build a religious building when your city is following the religion that offers it, and this building is not destroyed when converting to another religion, so building several buildings from different religions is posible. 5.5 Quick wars Prolonged wars are deadly for happiness, avoid them at all costs and do not be greedy. If you cannot take a city from a war, make a truce for ten turns and try again. Even the war of the hundred years had a lot of truces. In the worst case, pillage everything you can. If you can't force AI to declare peace, conquer a city and raze it! 5.6 Pace expansion. Every new conquered city is a big drag to happiness, so unless you really must hasten, try to expand at a pace that allows your happiness to recover. It is useless to take three cities in a row, and lost one for revolts. In the worst case, raze useless cities (at least you are not giving them to the enemy). If you only want cities for controlling the territory and the resources, use puppets, they usually cost less unhappiness and do not drag your progress. Puppets keep growing and building, so the biggest and eldest puppets in your empire might contribute more by being annexed. 5.7 Fight at sea. Naval combats produce great admirals who can be expended for some free luxuries. Even if you think you do not need a navy, the extra happiness is useful for a faster expansion. 5.8 City processes. A fast method to increase some yields is turning 20% production into a city process, when the technology allows. For example, if your cities are suffering from boredom everywhere, turning production into culture in most cities may put your empire back into positive happiness. With the caveat that nothing can be produced in such state, only unit purchases. (This may have been disabled for happiness purposes, need confirmation.) 5.9 Ally city states. An allied mercantile city state grants +5 happiness, and also has unique luxuries that cannot be obtained by trading with other civilizations, like glass and jewelry. Other city states may give you unique luxuries when allied too, and their granted yields are not to be dismissed. Special thanks to Omen of Peace, Mad_Madigan, Legen and Paramecium for their added tips and fixes.