|This article is about the current version of DF.|
This page is a list of hidden or unexpected aspects of the game, once known as HFS, or Hidden Fun Stuff. Though technically 'HFS' is used in the dev logs to refer to anything Toady doesn't want us to know about until we find it ourselves, players have appropriated the name to only refer to... well, we won't spoil it for you.
 Fluctuating Subtitle
When starting up the game, on the title screen where the player first chooses what to do, the top reads:
Slaves to Armok: God of Blood Chapter 2: Dwarf Fortress Histories of ...
'...' will be generated each time the game is opened. Some combinations include "Histories of Avarice and Resourcefulness" and "Histories of Jealousy and Tenacity." Generally, the words will include a synonym each of "greed" and "stubbornness", which as we all know fit the hairy little blighters like a cave spider silk glove.
 Dwarven Daydreams
Some dwarves like Toads for their beauty, an obvious inside reference to Toady One.
 So What If I'm Dead?
 Bey@nd Quality?!
For about one frame, the word "Beyond" in the Bay 12 Games Beyond Quality intro turns into "Bey@nd". Nobody knows why.
In the Bay 12 Games Beyond Quality intro, when the program is saying "Quality", grab the title bar and drag it around a bit. Release, and when the lines appear, you'll hear a pig sound.
 Help Screen
If you press the ? key 4 times you will be sent to a screen that appears to be the deepest part of the help menu, seeing as pressing ? from there will not do anything interesting.
 Intro Movie
Not quite an easter egg, but the sequence seen during the intro reflects the layout of a typical fortress from the old 2D versions, proceeding past the cave river and chasm and concluding with a miner breaching the magma river and causing a lethal flood.
 Toads as the default creature
Toads are the first creature entry to be parsed in the raw files, being the first creature listed in the first file ("creature_amphibians"). Hence, many incidences where the game attempts to pick a creature type and fails will result in "toads" being picked as a default.
When a creature is named (not for killing a dwarf), you get a message like : "The dwarves named a resident Cave Swallowman Urist McSwallowman". If you are in adventure mode and that all the dwarves/humans/elves/goblins are dead, you get the message : "The toads named a resident Cave Swallowman Urist McSwallowman".
A small egg, mostly because few have seen it. An old fort that's around 50 years old or so will grow moss on its stone block constructions. Not much is known about moss, except that it can only occur in certain Biomes.Verify for v0.34.11
 Trade agreements with Goblins and Kobolds
If you view a Goblin civilization in theivilizations menu(provided that there is one) and navigate to the Trade agreements tab, it will say that you have an agreement with them that they provide you with Terror and you give them Vengeance in return. Similarly, viewing kobolds will reveal an "agreement" in which they import Petty Annoyance and you export Death.
 Cats as Legendary Climbers
All cats are legendary climbers by default. That's impressive, given that cats can't gain even Novice in any other skill, and especially given how difficult it is to reach Legendary Climber as an adventurer.