Stealing kills is the practice of gaining exp while reducing the amount of exp gained by a competitor.

Rangers can attack more freely than those using other skills. They can team kill for half the exp.

Others can also steal kills from rangers.

Killing monsters on the same screen as someone else can be considered stealing kills if you are trying to disrupt their training.

Outside of the badlands, players can't kill each other, but they can still compete for resources or exp.