Crafting

Crafting is a gameplay mechanic introduced in Metro Exodus that allows the player character to create ammunition and various consumables, such as medkits, filters, or grenades, using materials collected while exploring the post-apocalyptic world.

Crafting Resources
There are two kinds of resources the player character needs in order to craft. Some items require only one kind of crafting material to produce, but most recipes require both of them, although in different quantities. Resources can be collected when exploring abandoned buildings or vehicles, they can also be found in openable boxes and crates. Some mutants can also be looted for resources once killed. Another way of obtaining resources is scrapping collected ammunition or consumables (see Functionality for more details). The amount of resources the player character can carry is infinite.

Materials
Materials are various mechanical components or just scrap metal, required to produce all ammunition (including pneumatic ammunition) and throwables. Smaller quantities are also needed to produce medkits and filters. Materials are also used to repair a damaged gas mask. Materials are represented by an icon which shows a wrench and a bolt nut. In the game world, they usually look like various pieces of wire, empty cans, small boxes with screws, bolts or bearings etc. They can also be obtained by scrapping parts from weapons dropped by dead enemies - if the player character disassembles a weapon with attachments that are already in their backpack, the attachments will be converted into materials.

Chemicals
Chemicals are the second crafting resource, slightly rarer than materials, but still fairly common. Chemicals are needed for crafting combustion and special ammunition, medkits, filters and explosive throwables (grenades and molotovs). They are also used for weapon cleaning. Chemicals are represented by an icon which shows an Erlenmeyer flask with a bubble-producing liquid inside. Chemicals are usually found in various bottles, canisters or other liquid containers. Another way of getting chemicals is by collecting luminescent mushrooms and nettles. Dead snakes and worms can also be looted for chemicals.

Crafting
The player character can use either their backpack, or a workbench for crafting. Backpack can be used nearly anywhere, as Artyom carries his backpack almost at all times since he first gets it at Volga, but it only allows to craft consumables, pneumatic ammunition and non-explosive throwables. Workbenches are only found in settlements, hideouts and at the Aurora, but they allow the player character to produce all kinds of consumables, ammo and throwables and also to repair their gas mask and clean their weapons. List of craftable items, together with required materials, can be found below.

Modifying Equipment
Both the backpack and the workbench can also be used to modify weapons. Any collected attachments and upgrades can be mounted to any weapon that accepts them at any time, with no additional cost. This means that Artyom can modify his weapons in the field in order to adapt to various situation (for example, a silencer can be attached to a weapon is a stealthy approach is required, or a reflex sight can be swapped out for a scope when Artyom gets into a long-distance firefight.)

Artyom's suit and other parts of his equipment can also be modified. However, this requires access to a workbench.

Neither weapon attachments, nor suit upgrades can be directly crafted. They have to be found in the game world, either looted from dead enemies, or just found while exploring. The backpack and the workbench can only be used to equip already collected upgrades.

Scrapping
Any craftable item can also be scrapped, or dismantled, in order to receive a small amount (rougly 20 % of the crafting cost) of crafting resources back. Although not very profitable, as most of the materials are lost, it can be used to scrap ammo types that the player character is not using and has collected them from dead enemies. It is also useful in an emergency situation when the player character urgently needs a medkit or a gas mask filter, but doesn't have enough resources available to craft them.

Trivia

 * Crafting was introduced to replace vendors, as outside of the Moscow Metro, military grade rounds have little value and are not accepted as currency anymore.
 * Sometimes, after a story mission is completed and the player character returns to the Aurora, a certain amount of crafting resources is added to their inventory after opening Aurora's workbench. Usually, the player character receives the resource they have less of in their inventory, and the amount is close to the difference between the two resources (for example, if the player character has 200 materials and 100 chemicals, they will receive roughly 100 chemicals). It's unknown how exactly this mechanic works and how to calculate the exact amount of resources received though.