Area of Effect, or AoE, are spells which affect multiple targets within a pre-determined radius set by the game mechanics. These effects range from HoT spells to DD spells and cover all points in between. Traditionally (as far as MMORPGs go), the anchor target (location at which the caster is aiming the spell), and those closest to that target, are affected the most by the AoE effect, with diminishing returns as the spell radiates outward. In Dragonica, where there is no targeting system, all enemies take full damage.
Some AoE effects are cast or used without having to target someone or something; the caster is the anchor for the spell. The effect/damage radiates outward from the caster up to a given range, affecting all targets, or the first given number of targets the expanding 'ring' impacts. These types of spells are referred to as PBAoE, which stands for Point Blank Area of Effect.
Caster classes that are weak physically tend to have powerful PBAoE spells (if granted by their class). These sorts of spells require them to be right next to multiple hostile targets, so the spells are designed to be worth the danger. Melee- and tank-type classes such as warriors are usually designed to take damage from multiple targets, and as such their PBAoE-type abilities tend to be very weak.
PBAoE can also stand for Personal burst area of effect, indicating the effect radius bursts outward from the user.