In the 26th century, Dalek Killers (also called DKs) were criminal citizens of the Earth Empire who were given a chance of having their sentences of death by vaporisation commuted if they fought the Daleks, with miniscule odds of survival. The Earth Empire judiciary offered, as an alternative to execution, the chance to choose from a wide variety of weapons prior to teleportation to a Dalek Empire planet, where they would do their best to survive.
The Dalek Killers had only a slim chance of living; odds of six hundred million to one were one estimate. Only a quarter of the criminals survived the experimental teleportation technique from the "Dee-Kay room". Of these, the survivors had an average life expectancy of just under two and a half hours. (COMIC: Abslom Daak... Dalek Killer)
Abslom Daak was the most notorious Dalek Killer of all. Others included Máire Mab Finn, a contemporary of Daak's, who chose DK duty after her trial for political terrorism. After her return to human space, Máire served as high priestess to a group of Travellers on the planet Heaven. (PROSE: Love and War)