Elemental damage

Elemental damage is a modifier that exists on certain attacks and weapons. Elemental damage is one of the manifestations of Light and Darkness, and can be used to a player's advantage to make their attacks more effective. It comes into play for both Guardians and enemies.

Elemental types
"A spark can give life...or take it."

- Grimoire Arc text.

"Sometimes the only answer is to burn it all away."

- Grimoire Solar text.

"It's fitting, then, that we have weaponized the unknown."

- Grimoire Void text.

"Darkness resides within, beckoning you. This is a truth we cannot hide from, so we must embrace it."

- The Stranger

There are five types of damage types:
 * Kinetic—White—the default damage type on most weapons. Will cause basic damage to any enemy.
 * Solar—Orange—causes Solar damage.
 * Arc—Blue—causes Arc damage.
 * Void—Purple—causes Void damage.
 * Stasis—Indigo—causes Stasis damage.

Weapons
Weapons can be infused with elemental damage; by default, most weapons only do kinetic damage, but some may come with modifiers. The modifier is indicated not only on the weapon's stats but also in the weapon menu on the HUD. At the common level, only Fusion Rifles deal elemental damage, but at higher levels nearly all special and heavy weapons deal elemental damage. Only a handful of primary weapons deal elemental damage, and most of those weapons are typically acquired in Raids.

The damage type on most weapons is random, though some weapons such as Exotics or Legendary Raid weapons have a set damage type.

In Destiny 2, all Energy slot weapons do Arc, Solar or Void damage, Kinetic slot weapons do Kinetic or Stasis damage and Power weapons do all damage types except Kinetic. The perk Osmosis on a kinetic weapon turns weapon damage into the same as your subclass when a grenade is used, until the weapon is swapped.

† Murmur is capable of switching between Arc and Solar damage whereas Hard Light and Borealis can switch between Arc, Solar, and Void

‡ Two-Tailed Fox fires a Solar Rocket and a Void Rocket, but its in-game element is void.

Subclass elements in Destiny
Each Guardian subclass focuses on one type of elemental damage. This extends to melee attacks, grenades, and Supers.

Enemies
Elemental damage will do bonus damage against certain types of enemies. The most obvious way to tell if an enemy is weak to a certain damage type is to see what color shield they have; for example, Fallen Captains with blue Absorption shields are weak to Arc attacks. Every race has at least one type of enemy shielded by default but will also have another type of enemy that's shielded whenever the Epic modifier is active (or during certain public events). In addition to the below list, Nightmare Hunts will also frequently spawn large groups of enemies (typically the lowest class associated with the Nightmare's original race, which normally should not be able to be shielded) with Solar shields that are unusually resistant to even matching elemental damage. Nightmare Breaker mods, obtained from the gamemode, are required to effectively penetrate these shields.

† Indicates enemies that alternate between different shield types.

¥ Indicates that the enemy gains shields in high difficulty activities or in otherwise special circumstances.

Enemy weapons and abilities typically have their own elemental damage types as well. Normally this doesn't come into play unless players are playing a mission with damage modifiers on. For example, a Nightfall mission with a 300% boost to Arc damage applies to both Guardians and enemies, so enemies that do Arc damage are especially dangerous. Note that Taken versions of enemies will do a different type of elemental damage than the original base enemy.

Trivia

 * It is unclear whether there is necessarily a distinction between the elemental damage done by weapons and the corresponding manifestation of the Light or Darkness associated with a given element; for example, a weapon which does Arc damage may not necessarily be imbued with the power of Arc Light, but rather merely fire electrified ammunition. In contrast, some weapons clearly do derive their power from the Light or Darkness, such as Salvation's Grip (which fires Stasis projectiles).
 * This is backed up by Ikora's and Drifter's notes on the elements, Ikora states we do not know what came first, the Light or the Elements, but they are fundamentally linked like Twins, and Drifter states the Pyramid's energies are getting the Elements all twisted up
 * Osiris states that the Elements are a means to communicate with the Light, but recently, now with the Darkness.
 * There are several types of planetary materials that responds to the Elements, Relic Crystals inside Relic Iron for Void on Mars, Zeptocyte Cores inside Spinmetal Leaves for Arc in the Cosmodrome, and Soliton Flares inside Helium Filaments for Solar on the Moon.

List of appearances

 * Destiny
 * Destiny 2