"SEVEN GUSY FOUND A SIGHT! LOL, WE GOT SUM BEER HEAR"
Armok believes the most critical lesson in fortresses is to keep the citizens alive. (Your definition of what constitutes a "citizen" versus a "non-citizen" is totally up to you.) Citizens have a few simple needs:
- Citizens who are exposed to freezing or scorching weather for too long will die. Get them into a subterranean area any way you can. (Subterranean areas are always at a constant survivable temperature.) Their fat and clothes will protect them for a while in freezing weather, but against scorching weather there is no protection. You get to a subterranean area by digging. I hope you brought a pick!
- Citizens must drink. Citizens who are healthy want their favorite beer, but they'll take any beer pretty gladly. They'll drink water if there's no other choice. Citizens who are sick or injured need water. Citizens can also drink dirty water if they have to. Dirty water will get them sick, and they'll probably die if they come down with the kind of stuff that's in dirty water.
- Beer is made at the brewery, from plants or honey. The brewer needs a barrel (made from wood or metal) or a large pot (made from stone, glass, or clay) to put the beer in. Strangely, he doesn't need water in order to brew. The plants can be gathered from naturally-occurring shrubs, grown at a farm plot, or bought from the caravan. Honey is gathered from your beekeeping area (until it bugs out). Shrubs that get walked on even a little bit will die. If shrubs are sparse in your area, be careful where you tread!
- Water is found in streams, rivers, lakes, ponds, oceans, and subterranean caverns. Nearly every map has water, even if it's only subterranean. The dwarves can drink non-salt water directly from the source, but they don't like that and will use it as a last resort. They prefer a well. You can build a well over water to make them like the water better. But if the water isn't flowing water, it'll be dirty. You can make dirty water clean by putting it in a reservoir that is more than one Z-level deep with water. This takes time to construct, but a safe, clean water source is a staple in every fortress.
- Citizens must eat. If there's edible stuff in the fortress (even live vermin), the citizens will know what to do with it. Citizens get really unhappy resorting to catching and eating their own live vermin. It's also possible to starve to death that way. So it's best to have another, more reliable source of food. Citizens like food best if it's been cooked at the kitchen into a quality meal. Food comes from tons of sources:
B. Fisherdwarves can catch fish from water. This is also a great source of food, especially if the water has flow. If it has flow, you won't ever run out of fish!* Beware as your fish and turtles can go extinct if you over-fish non-flowing water, such as ponds.
((Note: At least in DF2012, you most certainly will run out of fish from flowing water. Fish are no longer a long-term food source.))
C. Butchers can slaughter animals into edible meat and organs (and other inedible products you can use). Sometimes they can slaughter very-recently-dead animals, but live ones work a lot better. Even smaller animals provide a very large amount of meat, if they provide any at all. (One butchered adult sheep can feed four dwarves for a year, for example. An adult grizzly bear will feed five.) You can get animals for your butcher by buying them from caravans, hunting them, catching them in cages, breeding wild or tame animals within the fortress, or just killing wild animals by accident or with traps or soldiers. Wild animals are not reliably butcherable, but some of their corpses will be.
D. The berries and other plants you gather from shrubs can be eaten outright.
E. You can grow crops for a very reliable, steady source of food. Edible crops include mushrooms, berries, grain for flour, sweet pods for sugar and syrup, and the all-important spices. An unskilled farmer with two small farm plots and enough seeds can keep dozens of dwarves fed by himself every year, and a legendary farmer with the same can feed over three hundred dwarves. So, usually your farmer will produce more food than you need. The excess food makes very valuable trade goods for the caravan, especially if it's cooked.
F. Honey and royal jelly can be gathered from an artificial beehive. These cannot be eaten until cooked at the kitchen. There are many bugs with beekeeping** in DF2010 and it can be a frustrating industry to try to run.
((** I'd just like to add I find this particularly tragic, personally.))
Also, the bugs with beekeeping seem to persist in DF2012 as well.))
G. Milk can be cooked at the kitchen, or processed into cheese. Milk comes from milking tame milkable animals at the farmer's workshop, or buying it from the caravan. There are bugs with the pastures these animals need in order to survive in DF2010, and keeping “grazer” animals can be an exercise in frustration.
- Citizens must be kept happy enough to not throw violent tantrums or go insane. Insane dwarves will starve and dehydrate themselves, and insanity cannot be cured. Dwarves will go insane from unhappiness, and also from trying to make an artifact but not having the materials they want. Keep a good selection of materials around the fortress for the latter. As for the former, a citizen's state of happiness is summed from many sources. Here are some examples:
- A friend, family member, or pet dies
- They witness any friendly creature's death
- They see a corpse of a pet or a member of their civilization lying around somewhere in a decayed state
- They come into contact (line of sight) with a creature they detest. Most dwarves detest rats or roaches, and these tend to be common in farms and food storage areas. Employing a cat can go a long way to keep these pests at bay. All dwarves also hate being harassed by flies. Flies will unavoidably swarm around where there are corpses or food. Keeping food out of the main walkway is a good idea, but dwarves will still be harassed by flies when they go to pick up food to eat. This seems to be an unavoidable source of unhappiness, unless you can somehow avoid stockpiling food. (Let me know if you do.)
- They are attacked violently while a civilian
- They survive an accident, such as a cave-in or near-drowning
- They drink the same type of booze too many times in a row
- They drink unclean water, or eat vermin they personally caught with their bare hands
- They get quite hungry, thirsty, or tired
- They don't get to sleep in appropriate quarters (normal dwarves just like a low-quality bed to sleep in, but mayors need "decent quarters" to remain content, and nobles need much more)
- They talked to a noble (only if the dwarf doesn't care for authority)
- And many other sources of unhappy thoughts.
B. Happiness. Citizens are made happy by the following types of things:
- Being near mist (like a waterfall)
- Talking with family members, friends, or any dwarven child
- Being near their pet or a beloved creature
- Eating in a nice dining room
- Sleeping in a bedroom finer than one's station in life
- Admiring an owned object or owned room
- Admiring a well-crafted or well-built object, or being in close contact with an object the dwarf likes
- Eating a favorite food or drinking a favorite booze
- Drinking pure water from a deep well (more than one z-level water depth)
- Being let out of a cage. (Dwarves can't get into a cage through normal means, but cage traps will capture them if they're unconscious or caught in a web.)
- Continuing to live life with an unpunished crime. Murdering other members of the dwarf's civilization is a crime, and so is anything the nobles say is a crime--such as failing to meet a mandate.
- Being brought food or water, or brought to rest in bed (such as after an accident)
- Recovering from an illness or injury
- Becoming a parent, spouse, elected official, or noble
- Making an artifact
- Having a bath
- Having a bath with soap (much happier thought than just having a bath)
- And many other sources of happy thoughts.
- A spectacular enough accident has the potential to wipe out your fortress. Cave-ins, floods, fires, ill-conceived traps or constructions, falls from great heights, drowning, and just about any other conceivable type of accident can kill the citizens. Be careful when you mine and build.
- Finally, citizens must be protected from physical harm in the form of invaders and aggressive wild animals. These enemies come with varying degrees of determination, and will arrive from the surface or the caverns if they can find a way to reach you. It is up to you to decide how to protect your citizens from hostile forces. Having a sealable entrance you can put your dwarves behind goes a long way to protect the citizens from hostiles in a young fortress, but it is not required. You can deploy traps of all kinds, drawbridges, lockable doors, siege weapons, land mines, personnel, plague, extreme heat or cold, and vicious trained, tame, or wild animals (such as dogs, wolves, black/grizzly/polar bears, and large cats) to protect the fortress from hostiles.
Some types of defenses are very good against some types of enemies and not others.
- Only one weapon works on every enemy: entombment. You can encase anything in obsidian or ice, or bury it under a cave-in of natural rock, to kill it.
- Magma is highly effective against everything except forgotten beasts, and foes that normally live in magma.
- Upright spear traps work really well against enemies with organs, but they're pretty useless against an organless foe that is composed of things like vomit, fire, or rock.
- Flying enemies won't come down and stand on your traps or fight with your melee soldiers, unless there's no other way to get to the place they want. Otherwise those weapons can be very effective, depending on the quality involved and any natural resistances of the enemies.
- War dogs, grizzly bears, and the like are good at slowing down enemies and can kill almost as well as a dwarf soldier--but enemies with metal weapons will hack them to pieces with very little effort. (Note: Animals are an extremely bad choice to use against goblins in DF2010.)
That is Armok's introduction to Dwarf Fortress.
TLDR: If you can keep at least one citizen alive, you