The Gunsmith is a feature in Call of Duty: Black Ops III, Call of Duty: Modern Warfare, Call of Duty: Mobile and also Call of Duty: Black Ops Cold War. It allows the player to customize, view and build out their weapons incredibly precise, as well as select multiple attachments and optics.
Call of Duty: Black Ops III
With Gunsmith, players can design and create cosmetic variants of pre-existing weapons outfitting their guns with the choice of five various attachments including an optical attachment and Paintjobs. Most weapon attachments have approximately four to five cosmetic variants which allows the player to further change the appearance of their weapon, alongside these features players can name their weapon.
The players can make custom camos for their weapons to the top and sides with up to 64 layers, similarly to the emblem creator. The players can also inspect their weapons with camo and attachments in full 3D and rename their weapons from the actual gun name to a custom, completely desired one. Weapon painting is absent on the Xbox 360 and PlayStation 3 versions of the game.
Call of Duty: Modern Warfare
Gunsmith returns in Call of Duty: Modern Warfare, allowing the player to customize their gun with various attachments and Gun Perks. Attributes as "integral" to a gun as the barrel length and the caliber can be changed as well at higher levels, allowing for e.g. the base 9mm AUG to equip 5.56 rounds and function similar to an assault rifle. Some of these changes, such as changing the stock on a MP5, will change the weapon's name as well.
A few blueprints with advanced attachments are provided in the player's Armory. Players can choose to use these pre-modified weapons in their loadouts while the base weapon itself may not have these modifications unlocked, jump-starting their modification progress and possibly giving an advantage.
Blueprints allow players to use weapons they may not yet have unlocked, though they may not change the attachments on the blueprint until the base weapon is unlocked.
As of the Season Three of content, Gunsmith Customs are available. It allows players to use different blueprint variations of attachments combined on a single weapon. For example, a user of the AK-47 may use the Monocle Reflex Sight seen on the Pink Perforator blueprint in tandem with the Skeleton Stock seen on the Revolution blueprint.
Call of Duty: Mobile
Gunsmith returns in Call of Duty: Mobile, having been added to the game on August 15, 2020 as part of the Season 9 Conquest Update. It works the same way as in Call of Duty: Modern Warfare, allowing the player to customize their gun with various attachments and Gun Perks.
Gunsmith was updated in Season 13 Wint3r War; the attachments stats are now displayed with numbers, similarly to Call of Duty: Black Ops Cold War.