To activate PK you must press your PK key (Ctrl) and attack.
When you attack a player, your name becomes pink, means you are in PK Status (it lasts 1 minute from the last attack). In this Status, any other player can kill you without getting into PK Status, a player would turn purple if they initiated combat on anyone who was not purple or red and if they kill it would turn red.
Pk points disappear over time which will turn your name back white once you reach 0 PK points ('you can check your PK point with the following command in chat !pkpoint)
If you PK as white a PKer pink/red you won't turn in PK Status, the PK Points of the killed PKer will decrease.
If you PK as red another red PKer your PK Points will increase, and the PK Points of the killed PKer will decrease
In Gate to Heavens, character will die many times and the player must often sacrifice some experience points (XP)
Pk is disabled in main towns and low levels area.
Player killing, or PKing, is unrestricted PvP resulting in a character's death. Some games offer open PvP (also sometimes called world PvP), where one player can attack another without warning anywhere in the game world. Ganking (short for gang killing) is a type of PKing in which the killer has a significant advantage over his victim, such as being part of a group, being a higher level, or attacking the victim while they are at low health.
PK can also create additional facets in the community. In Gate to Heavens, a rift formed between those who enjoyed PKing, those who enjoyed hunting the PKs and those who simply did not want to fight at all.
Character death in an online game usually comes with a penalty. so habitual PKers can find themselves ostracized by the local community (A pink to black name will replace your white name depend on how many players you have killed, More your PK point increase more your name will become darker, a penalty will also be applied "NPC shop price will be increased, teleport fee increased, the amount of experience lost when you die will be increased as well" )
A rarer form of player killing involves inciting a monster to attack another player. The reason this is rare is because the monster is more likely to attack the one who is trying to do the killing. Often a player will have to lure the monster towards the other player and run away so that the monster (if it is aggressive) will look for a new target or use a monster AOE damage to kill someone, which may be the other player. This behavior is often found in otherwise purely 'PVE' games
Anti-PKing, also known as Player Killer Killing, PK Killing, or PKK, is a form of in-game player justice. Often motivated by an overpopulation of in-game player killers, Anti-PKs hunt Player Killers and Player Griefers with vengeance.