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
"Arc is the element of motion and conduction, and is created when the electromagnetic forces of our universe struggle to achieve balance. According to Ikora, Arc teaches us that change is a fundamental aspect of the universe."

- Osiris, on Arc

"Solar requires us to both exploit and rely on the power of our sun. But to master it is to understand the star's duality. The nuclear force that scorches anything foolish enough to draw near... is the same force we harness to heal."

- Osiris, on Solar

"Void is the element of cosmic distortion. It is the pull of gravity and the promise of entropy. The vacuum of space, and the gravitational forces that shape it, teaches us that emptiness is not nothingness."

- Osiris, on Void

"Stasis is the element of will and control. It slows, detains, and shatters. It was our first step into Darkness, and taught us the universe is not black and white as it first seemed... Control over self can foster control over others, but without power over the self, destruction runs wild."

- Osiris, on Stasis

"Strand is our newest foray into Darkness. As I understand it now, it is the elemental manifestation of psychic connection. All minds are connected in a web of consciousness, which we can now see and feel. To wield Strand is to pull on the hidden connecting threads, and to use them to create, manipulate, and unravel."

- Osiris, on Strand

There are six damage types:
 * Kinetic: White — the default damage type on most weapons, causes generic damage to any enemy.
 * Solar: Orange — causes Solar damage.
 * Arc: Blue — causes Arc damage.
 * Void: Purple — causes Void damage.
 * Stasis: Indigo — causes Stasis damage.
 * Strand: Green — causes Strand 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. In Destiny, 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, Stasis, or Strand 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, Borealis, and Dead Messenger can switch between Arc, Solar, and Void, and Conditional Finality can switch between Solar and Stasis damage.

‡ Two-Tailed Fox fires a Solar Rocket and a Void Rocket, but its in-game element is void; it also fires an Arc Rocket if the catalyst is inserted.

(*) Tessellation's in-game element is Kinetic, but the damage type can change depending on the element matching your currently equipped subclass.

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

Enemies
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.

Most Taken versions of weapons will do a different type of elemental damage than the original, and the Devil Splicers' common ranged weapons inflict Solar damage, while their melee weapons are still Arc. Some powerful enemies may have unique weapons that do different damage than their common versions.

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
 * Beyond Light (Stasis)
 * Lightfall (Strand)