A shock is a sudden effect, but not limited to the classical electric shock. Ironically, player characters don't get a regular shock, electric shock, or lightning shock spell, only mobs do.
There are many different shocks in the game, all of them represent a certain element and damage caused by it. All shocks deal instant direct damage but are usually not very mana-efficient and have a shared cooldown.
Shaman
The three Shock spells, which share a cooldown, are the main source of magic damage for the shaman on close range:
- [Flame Shock]: Instant Fire damage and DOT.
- [Frost Shock]: Instant Frost damage plus a [Slow] effect.
- [Earth Shock]: Instant Nature damage, plus it reduces the target's attack speed by 10% for 8 seconds.
The spell [Wind Shear] used to be known as the fourth Shock, Wind Shock.
Paladin
Paladins have a unique shock for both offensive and defensive situations:
- [Holy Shock]: Either heals a friendly target or damages a hostile one.
Others
There are other Shock spells that cannot be used by players but mobs or NPCs might have that ability as a part of its main damage sources. Naturally, those shocks have a cooldown as well but it is never more than 7 seconds:
- [Shadow Shock]: Powerful direct Shadow damage. Used by certain Necromancers, Witch Doctors and Duskwing.
- Shock or Lightning Shock: Direct Nature damage (lightning shaped) with no feature. Used by air elementals with lightning graphics.
- Arcane Shock: Instant Arcane damage and DOT. Used by Vexallus and Kiggler the Crazed.
Etymology
The Shock class of spells likely gets its name from the general definition of a shock - a discontinuous change in some property. Electric shocks and shockwaves both fall under this definition. Shock spells - being instant cast - can also be thought of a discontinuous change.