Similar to other rogue-like games, such as NetHack, it is possible in Dwarf Hammer to genocide, or destroy all instances of, a certain type of monster (or, unique to this game, Composition Type). This can only be done once per game, and only by requesting it as a favor from the Gnome Crimelord. Any creature or composition type destroyed remains destroyed not only for the rest of the game, but also for any legacy games.
The Gnomish FortuneEdit
While gnomes would not respawn in a new legacy game, the gnomish fortune-- some 10,000 ducats-- does. Some legacy gamers exploit this to build up their family's fortune over the course of a few generations by placing the money in the bank and giving their offspring the box key.