How can I ever put this to proper words?
Dwarf Fortress is probably the most ultimate sandbox game ever made. Just about everything is up to you in this vast city-building/roguelike masterpiece. You can generate a very customized worlds of yours just by altering the numerous parameters (such as 'number of civilizations', 'volcanism' and 'savagery'). Your world will have a history of its own, legendary heroes and bloody wars between nations. Unique stories, each time! Also, the generated worlds are diverse and truly huge. In theory, even one generated world in DF will last for lifetimes.
Example of a generated world
Alright, you can generate this freaking big world and stuff. So it's a good game according to RetroEnter... What the heck do you do really do in this game, then!?
The basic idea of this game is that you control 7 dwarves with pre-customized professions. The professions can vary from fishing to building siege engines and from architecture to wood cutting. Ideally, you should start the game with agriculture-oriented dwarves to supply food for your population. Fishing, farming and brewing are by far the easiest ways to feed your dwarves. Of course, agriculture surely isn't the only way to do it. The possibilities are truly endless.
Dwarf Fortress without a third-party graphic set
Your dwarven outpost will gain wealth as you craft things from wood or rock or from nicely engraved walls. Almost everything you do will increase your fortress wealth. Wealth lures immigrants and that's also your quickest way to expand and get richer faster. The only downside of being wealthy is that it will lure thieves. Kobolds are but pests and Goblins are a true nuisance. They will try to snatch your valuables and kidnap your children. Fortunately, defending what is yours is quite easy. Designing your stockpiles wisely will tremendously help in guarding them. Later on your created wealth will attract more hostile actions from the Goblins. They will start to make ambushes for your poor woodcutters and eventually try to wipe out all of your dwarves. In order to prevent this, you should for example take dogs with you when you are beginning your journey. Training them into war dogs will ease the pain with early intruders. Their value is significant in defending your fort later on, too. Dedicating some of your dwarves as soldiers will do the same trick also.
Dwarf Fortress with DFG graphic set
The art of trading is also a presented in Dwarf Fortress. Other civilizations, such as the elves, will send trade caravans to your outpost and you can interact with them by trading and by declaring demands. Bargaining itself slightly differs whether you are dealing with humans or with dwarves. Just remember this when you ordering clothes from humans: you'll get what you bargain for! (their clothes won't fit your dwarfs, nor will their armor!)
There's one thing you could debate on. Is this game 2D or 3D? In the early days DF only featured the X- and Y-axis. Nowadays it has the Z-axis, for height.
That means you can build realistic castles or towns, anything. Check out what your constructions could look like when you use a third-party add-on called 3Dwarf!
A fortress viewed in 3Dwarf
This game really has no ending. It just keeps going and going from season to season. It's just about having fun in your own personal way or accomplishing self-set goals. Anything. There's tons of more things I could write you about this game, but I think I am going to share them with you later.
Despite the extremely steep learning curve, you should give this one a go!
PS. This could be the future of Dwarf Fortress!