Character creation in Dwarf Hammer is ridiculously, some would say needlessly, complex, as it requires the player to actually create four characters-- two dwarfs and two she-dwarfs-- none of which you get to play as. Instead, after creating the four characters, the game pairs them up into mates, each of which produces two offspring-- one male and one female apiece, which inherit certain traits due to Mendelian inheritance. And then just one of those males is paired up with one of those females, producing the male dwarf that you ultimately play as.
While it is possible to "game" the system-- most frequently, this is done when chasing after zombie status, which has an equal chance of resulting in the zero hit point Zero-Move Death-- the random mating of the various dwarfs and she-dwarfs, each which must come from a different House and be born under a different Chinese Zodiac, not to mention the sometimes random way these traits are passed on and skip generations, makes it extremely difficult to predict your results with any accuracy.
This particular headache is reduced somewhat when your dwarf successfully mates with a She-Dwarf somewhere between levels 20 and 23. An offspring is produced, combining your character's traits with those of the (usually very powerful) She-Dwarf; when your current dwarf dies, you have the option of playing as the offspring on your next game (though, as always, the game world is procedurally generated and unique). Assuming that character can also make it to a She-Dwarf and successfully mate, the canny player can deliberately breed themselves an ideal starting dwarf, usually seven or eight generations down the line.