Lightning damage is perhaps the most recognizable and feared out of the three elemental damage types seen in Diablo series. In Diablo II, this is because of its extremely large damage range, sometimes ranging from a measly 1 to a player killing 2000. It is used by players who need to kill, but do not care even if the attack does almost no damage at all.
Lightning is used quite effectively by the Sorceress in her spells. The Lightning Spells tree is used by many Sorceresses for quick and ruthless carnage. Another common source of massive lightning damage is the typical javazon with Lightning Fury which is one of the most powerful skills for an amazon. Other mentionable lighning skills are Lightning Sentry, Death Sentry, Phoenix Strike, Claws of Thunder, Lightning Strike, Holy Shock and even Vengeance deals a lot of lightning damage.
But what is perhaps the greatest threat to the player's life comes in the form of Lightning Enchanted unique monsters, who have the ability to send sparks of Charged Bolt flying when they are hit. The sheer number of these bolts, combined with the aforementioned high range of damage has been known to send players running for their lives, especially in Hardcore, where surviving matters. In earlier versions of the game, there was a chance of a unique monster spawning with the Multi-shot bonus along with the Lightning Enchanted modifier, commonly called MSLE monsters in player lore. They were sure player killers at higher levels because the number of Charged Bolts tripled due to the Multi-shots modifier. This was deemed a bug, even though it was certainly legal according to game mechanics, and soon rectified by Blizzard in a patch.
In Diablo III, all classes except Witch Doctors occasionally use Lightning damage, although Monks and Wizards do so much more often. Critical Hits from Lightning skills rupture the target, tearing it limb from limb as excessive power is arcing electrical charges. Many Lightning-based skills Stun their targets.
Despite being used by almost every class and majority of skill runes, Lightning damage is, ironically, the least prevalent damage type in game by default, as there are only five skills that use Lightning damage without a skill rune: Fists of Thunder, Electrocute, Shock Pulse, Storm Armor and Fist of the Heavens.
Andariel's Visage, Stone of Jordan, Lidless Wall, Holy Point Shot, Schaefer's Hammer, Odyn Son, Storm Crow, Thundergod's Vigor, Gesture of Orpheus, Won Khim Lau, Swamp Land Waders and Eye of the Storm are the items with unconventional bonus to Lightning skills damage. Xephirian Amulet will render the character completely immune to Lightning damage (the attacks will actually heal the Nephalem).
Almost all Lightning Enchanted monsters are remembered in some form by players. A vast majority of players have been killed at least once by the aforementioned LE unique monsters. This makes them a very feared variety of enemies in the realms, feared almost as much as other players themselves.
But the game itself is not without its fair share of Lightning Enchanted super uniques. The Carver lord, Rakanishu is the first Lightning Enchanted boss encountered by most players. He does not pack quite a mean punch nor is he quite notable. But having to hear his name being recited by all kinds of Fallen as some sort of battle-cry makes him very notable.
Besides Rakanishu, the Council Member, Bremm Sparkfist was also a user of Lightning as his name implies. But he was severely nerfed in a patch that made him Cold Enchanted making his name almost irrelevant to his powers. Although he was reverted to Lightning Enchanted in later patches.
Though not a Lightning Enchanted Boss, the Lord of Terror himself, Diablo uses Lightning in one of his most dreaded signature attacks, the Red Lightning Hose. He fires the Inferno-like stream of red death with a deadly combination of Lightning and Physical damage, very unusual for a ranged attack. But nonetheless, it still has players fleeing from it when it is used.
Belial's attacks use the Lightning damage as well.