PK or Player Kill is type of Player versus Player battle in which one player attacks another without the prior consent of that other player. A PK can be initiated anywhere outside of safe areas - which include Towns and Colosseums, but can only be used to attack a player above level 30. The PK battle is initiated by right-clicking on the opponent and selecting "PK". A successful PK will result in the victim dropping one piece of equipment that is worn by the Main character or one of his/her Mercenaries - this includes Decorations and Mounts. Successfully PKing another player will cause the PKing player to appear in the victim players Blacklist. The victim can thereafter take revenge against the PKer anytime, anywhere as long as the PK player remains in the Blacklist.
Wartime is a condition whereby one nation declares war on another nation. During Wartime, the option to PK is available by any member of a Nation against a member of an enemy Nation. This form of PK can result in an ambush 3 vs. 1 battle.
King's Judgment can be initiated only by a King above level 100 of a Nation above level 5. A King's Judgement can be used against anyone above level 30 at any time. Using King's Judgement requires 125% Will.