Weapon Accessory

Weapon accessories are items that can be attached to a firearm to provide extra functionality, or swapped for a different purpose. Accessories are first featured in Battlefield: Bad Company 2, but appear in certain capacity in all Battlefield games. The player can choose accessories in the Customization screen.

Optics
Optics provide an alternative for a weapon's built-in sights (aka iron sights). Some sights merely elevate the user's sightline or otherwise increase peripheral vision, and often provide a reticle for improved aim. Scopes use lenses to magnify vision for long-range engagement.

Attachments
Many accessories can be mounted on a modular rail system such as the Picatinny. Prior to this, attachments were often custom-designed for specific weapons.

A modern weapon often has three rails, a top rail for optics, a bottom rail for underslung weapons or stability attachments, and side rails for other devices.

Weapon modifications
In certain games, parts of a firearm can be swapped out, such as the barrel or muzzle brake.

Alternate ammunition
A variety of ammunition is available for shotguns, 40mm grenade launchers, and mortars.

Shotgun shells

 * 12 Gauge Buckshot
 * Flechette Ammunition
 * 12 Gauge Frag
 * 12 Gauge Slugs

40mm Grenades

 * Fragmentation Grenade
 * Flechette
 * Buckshot
 * Smoke

60mm Mortar Shells

 * High Explosive
 * Smoke
 * Illumination round

Battlefield 2
The Assault kit uses an underslung grenade launcher instead of hand grenades.

Battlefield 2142
An underslung shotgun is available for the Assault class, along with a rocket launcher. The two accessories can be used at the same time, using the same ammo.

All weapons except for the Clark 15B and Clark 12-RDX have a distinctive sight or scope.

Battlefield: Bad Company 2
Specializations are introduced, some of which provide accessories for the player's weapons. Alternate ammunition is available for shotguns and grenade launchers.

Prior to Bad Company 2, all sniper rifles used scopes.

Battlefield 3
Accessories are given their own system, and are unlocked via progression with individual weapons. Weapons can have up to three attachments:
 * Optics:Sights and scopes
 * Primary: Underslung rail or stability accessory
 * Secondary: Side rail device or barrel improvement

Scopes are now optional on sniper rifles, to offset the new scope glint mechanic.

BF3 also reintroduces the mortar, with various types of ammunition.

Trivia

 * So far, all Battlefield games merely zoom in the player's view when a scope of any magnification is used. Sniper scopes may also block off vision outside of the scope. This limit's the player's peripheral vision, and is likely kept for game balance purposes.