Area of Effect
Area of Effect (AoE) skills affect a given area of the playfield, and not any one specific enemy; any enemy inside of the area will be affected by the skill. The affected area generally does not move over time, so aware players can move elsewhere to avoid the negative effects caused by the skill. Area of effect skills can affect all valid targets within the horizontal radius regardless of barriers or altitude.
In PvE, since the 2005/11/10 update, henchmen and creatures flee from AoE skills that do damage over time, but generally take 2-3 seconds of damage before fleeing. There are some few exceptions that are not recognized by the AI, for example Spiteful Spirit.
In PvP, use such skills to clear a tactically important area of opponents so your team can take and exploit such a breach in the opposing team's defense. In Guild vs Guild games, "Victory or Death!" presents an opportunity to use AOE skills on the archers who bunch up at the flagstand.
Most AoEs require a target; however, some will take effect around the caster. These are called PBAoEs—point-blank area of effect.
See also: Range
As stated above, computer-controlled creatures will flee upon being inflicted with such pulsing damage after two to three seconds. However, if the creature is effectively body-blocked by players or any other mobs (including spirits), it will be mind-frozen trying to reach its previous target or skill use location : hence a melee or touch-range Boss could be defeated easily, unable to attack or use any offensive abilities.