A death mark could be placed on someone that somebody else wanted to be hunted down and killed by a bounty hunter.
When Han Solo did not pay off his debts to Jabba the Hutt, Jabba placed a death mark on him. The death mark was so large that Solo felt he had no choice but to leave the Rebel Alliance in order to pay off his debt. This plan was thwarted, however, when the Rebels were attacked by the Galactic Empire and Solo was forced to flee along with Leia Organa and the droids R2-D2 and C-3PO in the Millennium Falcon. Darth Vader of the Empire then commissioned Boba Fett, a bounty hunter, to hunt down Solo.
The Trandoshan smuggler Feresk Tssat earned a death mark when he was hired by an Imperial governor to acquire a painting. The governor in turn showed the painting to Grand Admiral Thrawn who noticed that, unbeknownst to Feresk, the painting was a counterfeit. To escape the death mark, Feresk joined the Rebel Alliance as a starfighter pilot.
Pathfinder navigator Qilori of Uandualon believed the Chiss Junior Commander Thrawn earned a death mark by alerting the Lioaoin Regime that they were hunting pirates at the Lioaoin heartworld. Years later, General Yiv the Benevolent of the Nikardun Destiny told Thrawn at the battle over Primea that he had "earned death" for capturing one of his warships.
- Star Wars: Smuggler's Guide