Kal Online splits player versus player into two very different things. Duels are consensual and cost nothing. Open player killing runs through the assassin system, and you cannot start it by accident. Here is how the mask works, what the penalties are, and why the town board keeps a record of every assassin who dies.
Duels are the safe option
A duel is requested from the chat window by typing the duel command followed by the other player's name. It works anywhere, and it starts only when the other player accepts. Duels last up to ten minutes and end in a draw if nobody has won by then. A knockout ends the match, the loser can revive on the spot by pressing the revive button, and no experience is lost either way. Either side can walk away using the surrender command. The official pages add one warning: monsters still attack during a duel, so fight somewhere safe.
Becoming an assassin
Player killing requires the mask item. The official system description explains why: it forces anyone who wants to kill to announce the intention first. Masks are sold by the mask merchant in the Temporary Fort of Geum-Ohee Castle and at High Land of Sky.
Wearing a mask changes your name to a red "assassin" label and puts a mask on your character's face. If you are wearing bound items you cannot equip the mask at all. The client has commands to switch your display name between your real character name and the generic assassin label, so you decide whether your target knows who you are.
The two hour lock
Once you become an assassin the state cannot be removed for two hours. Being knocked out clears it early. You also cannot log out while in assassin mode. A warning message appears on screen whenever an assassin is nearby, so nobody gets ambushed without at least a moment of notice.
Who you can hit, and who can hit you
Assassins can attack every character except their own party members and guild members, and assassins can attack each other. The mask does not make you safe in return. Outside safe zones, any player can attack you. Towns and some beginner hunting grounds count as safe zones, and the client shows a non safe zone icon in the top left corner once you leave them. An assassin can only attack other players outside safe areas too.
What death costs you
- You lose experience, the same as any normal death.
- Your death counter does not increase.
- There is a 50 percent chance that you drop one item, and the roll includes equipped gear as well as items in your inventory.
- Any remaining mask time is wiped out if you are killed or if you suicide.
What you cannot do in assassin mode
- Trade with other players
- Open a personal shop or buy from one
- Set a fish trap
- Join a guild or accept an invitation to one
When an assassin is killed by another player, the kill is recorded on the town board with the assassin's name and the name of the character who killed them, plus the killer's guild. If several people pile onto the same assassin, the board credits whoever landed the last hit. The board keeps the fifty most recent entries and drops the oldest ones as new records arrive.
FAQ
Can I player kill without a mask?
No. The mask is the opt in, and it is visible to everyone around you.
Does losing a duel cost experience?
No. A duel knockout costs nothing and the death counter does not move.
Can an assassin attack guild mates?
No. Party members and guild members cannot be attacked, which is also why an assassin cannot join a guild while the mask is on.
How long do I stay an assassin?
At least two hours, unless you are knocked out first.
What happens if I die while wearing the mask?
You lose experience, your death counter stays put, and there is a 50 percent chance you drop an item.
Sources
[1] GameAgit: Kal Online PK System (official publisher guide)
[2] Kal Online official site: duel and assassin (PK) system