I recently started playing Civ V again after not playing in an awfully long time. I quickly found myself with a very unhappy empire and didn't really have a good plan to get out of it. I feel like I probably didn't know how to deal with it well back when the game first came out and I have absolutely no idea now. So, I decided to look up what was going on...
First off, unhappiness. Every city you make gives you 3 unhappiness right off the hop. On top of that every citizen in any city is worth 1 unhappiness. So from a strict unhappiness standpoint having fewer cities is better. This is probably where I most went wrong, as I had 4 small cities that couldn't grow because I was unhappy. I could have fit those many people into just 1 or 2 cities and been happy. Conquered cities are worse for unhappiness. Apparently if you play on bigger maps the unhappiness per city number gets reduced, and the same if you play on easier difficulties. This game was on a randomly sized map, but if playing on a huge map makes my people happier I think my next game will be on the biggest map I can find!
Next, happiness. A big source of happiness, and one I got unlucky on, is luxury goods. Each different one is worth 4 happiness. Now, when you consider that a new city is worth 3 unhappiness and a luxury good is worth 4 happiness it seems like a reasonable idea to build a new city to pick up a new luxury good. I did this recently in my game, by building a desert city by some gold. The desert city isn't great, but my civ is a little happier as a result.
You can also get happiness by building happy buildings (colosseum, theatre, etc...) but it turns out you can't just stand a ton of them in little cities to get really happy. Each city can contribute only one happy face from these buildings per base unhappy face from population in that city. This makes me sad, but I guess it means as long as you can build some buildings in a reasonable time the first 12 or so people in the city are 'free'.
You get 9 happiness right off the hop for playing on a decent difficulty rating. You get more free happiness on easier settings.
Every natural wonder you find is worth 1 happiness. I stopped exploring in my game, so I only found 2 natural wonders. I bet there's a lot more out there that I could find if I bothered looking for them. Probably not going to happen this game, but it's definitely something I need to keep in mind in the future. Having a scout or two just wandering around makes sense.
There are a few wonders you can build worth happiness. I got beat to them in this game because I stalled out on science (turns out when your cities refuse to grow it becomes hard to get science).
There are a bunch of social policies which can give you happiness. There are some that make your other buildings give happiness (for defenses, or libraries, etc...) and apparently this happiness is above and beyond the happiness from the normal happy buildings, which means a small city filled to the brim with these can actually net you happy faces even after accounting for the extra 3 unhappiness per city.
The India civ has a unique ability which halves unhappiness from citizens while doubling unhappiness from cities. So every city is an extra 3 unhappiness tacked on, but each citizen in those cities saves you half an unhappiness. So once a new city hits size 6 it's break even, and every guy above 6 is golden. I think my next game might feature India...
I don't feel like I have a good handle on how to deal with happiness yet, but at least now I understand what I'm dealing with. My tech plan in this game was really random, and I think I didn't get to a point where I could even build a happiness building until it was far too late. I was stuck building a city wall for one happy face thanks to a mediocre social policy. Really I think I needed to not expand out to 4 cities until I got the tech to build colosseums. Live and learn!