Skirmishes are PvP encounters in which anyone will be able to participate. Each faction can fight the opposite faction in a zone's RvR area which is represented by the orange highlighted part of any map.
Skirmishes are the most basic form of PvP available to any player in WAR. Skirmishes consist of 1 on 1 (or group vs. group) combat that will see each side fight until one or both sides die, or flee. Because skirmishes are open world combat they do not follow any structured rule set. This means that players can attack a single opponent as a group (known as ganking), attack a player of a much lower level , or attack while another player is fighting a mob. Because there is no rule structure, players can and will do anything within their power to win the fight.
Skirmishes can and will be fought for any reason. Whether a player holds a grudge against another player, sees an opportunity where they hold the upper hand, or decides that they wish to PVP at that moment, eventually every player will find themselves skirmishing in an orange PVP Zone. However, because of the overall purpose of PVP within WAR, winning a skirmish is helpful to your Army. With every kill in a skirmish a player earns victory points to aid their realm. This makes open world PVP very desirable, especially since the nature of skirmishes allow for the initiating player to quickly and with little effort score victory points for their army.