Area of effect (or AoE) is a term used in many role-playing and strategy games to describe attacks or spells that can affect multiple targets within a specified area*. Spell vamp and omnivamp have reduced effects when used with AoE abilities.
Types of AoE
Chain
Chain area of effect spells start their effect with a single target, but, if there is another valid target within the range of the chain, the effect will jump to that target.
This type of ability usually bounces only a limited number of times and cannot hit the same target twice. There are, however, exceptions:
Pyroclasm can hit the same target more than once.
Malefic Visions can jump an unlimited amount of times, provided there is a target nearby after the current one dies.
Some of the abilities of this type also have an increase damage per bounce, 
Double Up, for example, deals increased damage on the second (and last) target.
Conic
Conic area of effect ("CAoE") spells affect a cone-shaped area that usually starts at the feet of the caster.
Examples:
Location-targeted
With location-targeted area of effect ("LTAoE") abilities and spells, the player selects a location on the ground as the anchor for the spell's effect. One carefully places this around the targets and clicks to start casting/channeling. All units that are in that area or remain in that area for channeled or persistent LTAoEs suffer the damage and/or effects.
Linear
Linear area of effect ("Skillshot") abilities require only a direction from the caster to be used and affect an area contingent on the ability's width and range. This type of AoE is dominated by projectile-based abilities where in the projectile acts as the carrier for the spell's effects, but there are some which do not have these and simply affect the entire area at once as CAoE spells do.
Examples:
Point Blank
Point Blank area of effect ("PBAoE") spells 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, within the radius.
Some examples:
Splash
A splash area of effect ability requires at least one target to trigger and subsequently affects an area around the struck unit. The primary target is not always affected.
Examples:
Hybrid
Given the sheer amount of abilities, some are bound to include more than one type of AoE. This is where a "hybrid" classification comes into play.
Some examples:
- Ground-targeted + Point Blank:
Crowstorm, Pounce, Rocket Jump. - Ground-targeted + Linear (A.K.A. Vector-targeting): The Equalizer, Death Ray
- Linear + Point Blank: Slice / Dice, Spinning Slash, Glacial Fissure
- Linear + Conic: Wild Cards, Volley, New Destiny
| Targeting Types | Auto (Passive · Self) · Direction · Location · Unit · Proximity · Vector (Collision · Radius) |
|---|---|
| Unit types | Champion · Minion · Monster · Pets · Structures (Turret · Inhibitor · Nexus) |
| Effect types | Ability effects · Attack effects (On-hit) · Area of effect · Damage over time · Heal · Multi-hit · Redirected damage · Shield · Single-targeted |
| Ability types | Aura · Blink · Buff · Combat status · Crowd control · Damage (Ability · Basic · Magic · Physical · True · Nexus Obelisk · Execution) · Dash · Debuff · Invulnerability · Pet · Sight · Spell shield · Untargetability · Ward |
