Duels

Duels are authorized Player vs. Player fights that take place even in safe areas and will not change a player icon from green to orange by killing the opponent.

At the beginning of the duel, the player will have 60 seconds to prepare for the duel. After the 60 seconds, the duel will start and players will clash.

Known games that have duels are Sword Art Online and ALfheim Online.

Procedure
To make a duel a player must send a request to another, the second player must accept and may decide then which type of duel it will be.

After a duel is concluded, a window that indicates the winner will appear between the participants if they are within 10 meters of each other. If the participants are farther apart at the end of a duel then two windows will appear near both the winner and loser.

Notable Duels

 * Kirito vs. Asuna (Material Edition 01)
 * Kirito vs. Kuradeel
 * Kirito vs. Heathcliff
 * Kirito vs. Heathcliff Final Boss fight at (Floor 75)
 * Kirito vs. Eugene
 * Kirito vs. Leafa
 * Kirito vs. Oberon
 * Asuna vs. Yuuki
 * Mosaku vs. Tonnura

Types of Duel
In Sword Art Online and ALfheim Online, there exist three types of duels :
 * Total Loss Mode: Rarely used in SAO, since it will only stop when a player's HP reaches 0, and that will mean permanent death for the loser. This is the one used for Sleep PK.
 * Half Loss Mode: The winner is decided after the other player loses half of their HP. Rarely used in SAO since a critical hit could could reduce someone's HP to the danger zone.
 * First Strike Mode: This is the most common, the winner is decided by whoever lands the first clean hit or whittle the opponent's HP to half.