40d:Losing

Losing is fun!

Either way, it keeps you busy.

Most new players will lose their first few forts; if when you lose a fortress, don't feel like you don't understand the game. Dwarf Fortress has a steep learning curve, and part of the appeal is discovering things for yourself. However, this Wiki serves as an excellent place to speed up the learning process.

If you lose, you can always reclaim fortress or go visit it in adventurer mode.

If you're looking for more ways to die horribly test yourself, try either the Difficult Seeds, Mega Constructions, Challenge Builds or the Goals pages.

Autopsy

Various things can cause you to lose a fortress.

Losing your miners

If your miners are killed in a collapse and their equipment destroyed, chances are good that you will no longer be able to continue your efforts. Consider abandoning your fortress. Alternatively, you can try to keep your fortress running long enough to request additional picks from your Outpost Liaison, who will arrive with the next dwarven trade caravan. It will take another year before they will return.
Also consider the tedious but fun option of making buildings outside! If your woodcutters with axes are still available, then you can build structures of wood. This is not recommended for very new players though, as it is intensely resource-demanding and takes a lot of managing to get right. (Also not recommended if you don't understand the z-axis system yet.)

Starvation

A serious danger, generally in the more inhospitable climates, is the loss of your dwarves due to starvation; if you are in the heart of a mountain with no soil to build on, it is possible you will not be able to establish farms. As dwarves begin to starve, they will become Hungry, then Starving. This will cause them to become very angry. When they die, their friends will become upset and will become even angrier, potentially causing the remainder of your fortress to break out in a terminal brawl.

Don't forget your alternative sources of food. Try butchering your animals, gathering plants, or resorting to hunting of local wildlife.

Dehydration

One of the biggest problems with a fortress that has no brook, stream, river, or other source of fresh water. Water must be rapidly gathered from stagnant pools and stored into an indoor basin or water tower, with sufficient depth before it evaporates. If this fails, all of the water on the map will evaporate and your dwarves will be left without any water. Without access to water any injured dwarves will slowly die of dehydration, since they can't drink alcohol.

Brewing can alleviate these problems, but in the future brewing will also require water.

Flooding accidents

The opposite side of the dehydration spectrum is having too much water. Remember that water can flow in 10 directions (the 8 horizontal ones as well as up and down). It is also worth remembering that, unlike water, magma does not flow upwards.

If your fortress is beginning to flood from sourced water, abandon all of the levels the water can reach immediately—drafting dwarves into the military and stationing them onto the surface if need be. You will never be able to recover those areas unless you can manage to pump out the water faster than it floods in, which can take over a year or two of game time to establish a functioning automated pump system. Generally, a flooding accident spells doom for your fortress.

Invasion

The goblins first come with about a dozen soldiers to siege your fort. Then they come again with about two dozen. Then three. Soon enough your traps are all sprung, your doors beaten down, and your dwarves are dead. Without some simple defenses, such as a moat, a horde of goblins on your doorstep can be deadly.

Wildlife

Goblins aren't the only creatures that want you dead. Be it unicorns, hippos, undead elephants or a giant cave spider, a sudden wildlife attack can quickly cripple or destroy an unprepared fortress.

Volcanic Death

Toady has stated that in the future volcanoes will be much less stable and much more deadly.

General Unhappiness

Think it's no big deal to leave your dwarves with a mediocre dining room, living room, and a generally inadequate fortress?

If there is little in a fortress to give your dwarves happy thoughts and enough to give them unhappy thoughts, then your dwarves will start to throw tantrums, go melancholy, and destroy your civilization. Unhappiness is more likely to occur if your fortress is suffering other kinds of downfall.