Crafting

Crafting allows building items from certain components.

Fallout 3
Scattered throughout the wasteland are notes called schematics. These can be picked up and read from your Pip-Boy from the Notes category in the Data section. Schematics contain information on how to build a custom-made weapon derived from junk parts that can be obtained throughout in the wasteland. Not only do they show you what parts make up the weapon, but they briefly describe how the weapon works and what it fires as well. You also can go to a workbench and select the weapon you want to build, and the game will tell you what you have and what you're missing to construct the weapon.

Once you have all the necessary components, simply approach a workbench, activate it, and a menu will pop up with a list of weapons you know how to build. Select the weapon you wish to make and after a few clinking noises a note should pop up on the upper left corner of the screen stating you have created that weapon. Not only can you make traditional weapons, but also special grenades and landmines.

In total there are 7 weapons you can make with schematics found in the wasteland. Each weapon has more than one schematic that can be found, with multiple copies generating the items in better condition (in the case of weapons) or generating greater quantities of the item (in the case of grenades and mines). Each weapon is unique in its own way and can be very fun to use—such as the Rock-It-Launcher, which can shoot just about any piece of junk you can find lying on the ground; or the Nuka-Grenade, which creates a large blast of flame that does devastating explosive damage, catches nearby enemies on fire, and causes radiation damage.

Fallout: New Vegas
Three basic types of objects in the world can launch the crafting interface: campfires, workbenches, and reloading benches. Each station allows the creation of a subset of items. Though many recipes are visible at any time in the game, some recipes will only appear when the player completes a quest or finds a special item. You may also find that certain companions or special locations can open special crafting interfaces for the player. Recipes have skill and ingredient requirements that must be met to proceed. If any requirement is darkened, that requirement has not been met. Any recipe that has all of its requirements fulfilled will appear fully lit. After using a recipe, the product(s) of the recipe will all immediately be available in your inventory.

Fallout 4
It is possible to craft a variety of in-game items like consumables or grenades using workbenches located throughout the Commonwealth. As opposed to crafting in Fallout: New Vegas, it is not possible to craft your own ammunition or ammunition subtypes in Fallout 4 in the vanilla game, with the exception of grenades, syringer ammo for the syringer rifle or Nuka-nukes for the Nuka-nuke launcher from the Nuka-World add-on. Modding is carried out by applying pre-defined components to armor and weapons, like adding lead to armor parts for enhanced radiation resistance or equipping several types of barrels on firearms. Modding or crafting does not generally require schematics, but certain active player perks are affiliated with some types of modding, e.g. Science! for modding energy weapons or Armorer for armor.

Fallout 76
It is possible to craft a variety of in-game items like consumables, armor, and weapons using workbenches located throughout Appalachia. Like in Fallout: New Vegas, it is possible to craft ammunition in Fallout 76. Modding is carried out by applying pre-defined components to armor and weapons, like adding lead to armor parts for enhanced radiation resistance or equipping several types of barrels on firearms. When scrapping, you will "discover" new mods to put on the gun you have been scrapping.

Van Buren
Van Buren, the canceled Fallout 3 by Black Isle Studios, was to contain various research projects which could be completed by science-oriented characters.