Duels

Duels are authorized Player vs. Player fights that take place even in safe areas and will not change a player's icon from green to orange or red.

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 (Edition 01)
 * Kirito vs. Kuradeel
 * Kirito vs. Heathcliff
 * Kirito vs. Heathcliff Rematch
 * Kirito vs. Eugene
 * Kirito vs. Lyfa
 * Kirito vs. Oberon
 * Asuna vs. Yuuki
 * Mosaku vs. Tonnura

Types of Duel
The types of duel are:
 * Normal 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.
 * 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.
 * Time-Limit Mode: The winner is determined by whoever has the most HP within the designated time-limit. (unconfirmed)