You’ll pick up a ton of stuff in Horizon Zero Dawn — from plants to machine parts to rocks. So what can with do with all of that junk? In this guide, we’ll teach you about currency, crafting, potions, traps, merchants, trading and more.Table of contentsHow currency worksBefore we begin, we should clarify that there’s no money in Horizon Zero Dawn. The closest thing to currency are metal shards. You’ll spend these a lot like money, but it’s not money, per se.We’re going to use phrases like “cash” and “buy” even though they’re technically not correct. It’s an easy shorthand and sounds better than some wordy verbal gymnastics about barter systems in the absence of a medium of exchange (thanks, Wikipedia!).The important thing to remember is that the metal shards you trade for a new outfit are the same shards you use to craft arrows.Making ammoThe first and most common thing you’re going to be doing with your vast junkyard wealth is making ammunition for your weapons. The simplest ammo is standard hunting bow arrows — requiring one scrap of metal and two sticks of ridge-wood. Later-game weapons like the shadow sharpshot bow have much more expensive ammo — precision arrows for the sharpshot bow cost 10 sticks, 8 shards and 5 pieces of wire. And that’s just arrows. By the time you pick up the rest of weapons in the shadow line of products — slings and rattlers and tearblasters (Oh my! #sorrynotsorry) — crafting ammunition becomes very resource intensive.Ammo can be made on the fly from your weapon selection wheel or in the crafting menu.Making ammo is a simple process at first and, you won’t have any trouble keeping up with gathering resources to offset how fast you consume them. Later in Horizon Zero Dawn, you’ll find yourself playing out a supply-and-demand simulator — demand for components like echo canisters will far outpace the supply. And you’ll have to learn to be careful with the ammo that requires echo canisters as a result.Some of this scarcity is just part of the game — expensive ammo is good ammo, so limiting the resources limits your access to overpowered weaponry — but there are a few things you can do to stay ahead of the curve.Pick up sticks until you have way too many. You’ll use your bow more than any other weapon and you’re going to make more arrows for it than any other ammo. You need a lot of sticks to keep up with that demand. (And sticks will come up again in the crafting inventory expansions section below.) At a certain point, you’ll have more sticks than you need, and then you can stop harvesting every piece of ridge-wood you see. Identifying that point is up to you and the size of your inventory, but like we said in our Horizon Zero Dawn tips guide, 2,500 is probably too many.Don’t spend all of your metal shards at once. As tempting as it is to spend your last shards on that new outfit, make sure you have some left over. Like we write above, the shards you use to buy clothes are the same shards you make arrows with. Spending your last shards can leave you without ammo.Common items can be used for ammo later. As your inventory fills up, it might be tempting to sell or drop some of the common items you don’t have much use for (we’re looking at you blaze canisters). But before you sell them all, plan ahead. Some of those common items get used up fast with high-level ammo.It’s OK to buy ammo parts from merchants. When you find yourself running out of components for ammo — like blaze or echo canisters — you don’t have to resign yourself to hunting down machines to restock. Just go to a merchant to buy them. In a game where you spend so much time foraging, it’s tempting to dismiss merchants and to try to be self-sufficient, but there’s no shame in just cutting out the middle-man (middle-machine?) and buying what you need. It’ll save you a ton of time.Crafting inventory expansionsAfter ammo, the second most common thing you’ll be using all of that junk for is crafting inventory expansions. Every type of thing you pick up or carry — weapons, outfits, resources, etc. — has a dedicated satchel, pouch or quiver. And these containers start off frustratingly small.Requirements for the final hunter bow quiver upgrade. (Please send fox skins.)Happily, you can expand everything. You can expand your resources satchel to 100 slots. You can also expand your hunter bow quiver to hold 60 arrows at once (assuming you can find one more GODDAMN fox skin).Like we said in our Horizon Zero Dawn beginner’s guide, you don’t have to worry about maxing out your inventory capacity right away, but you shouldn’t neglect it either. When you find yourself constantly out of room for resources or always running out of arrows in the middle of a fight, it’s time to see what you can do about storage space.The first couple expansions to any satchel, pouch or quiver are cheap — a few shards and sticks — but the fourth (and final) expansions are quite expensive, costing hundreds of shards and sticks and an obscure animal part or two. Here’s how to prepare yourself for these costs.Hunt animals, and pick up everything. We mentioned both of these in our Horizon Zero Dawn tips guide, but it bears repeating. Those rare drops from animals are going to come up in crafting — things like rat bones and fish skins — and having them before needing them will save you a lot of frustration. And having a(n un)healthy stock of ridge-wood will let you absorb the cost of an upgrade without sacrificing ammunition manufacturing.Don’t waste resources on weapons you don’t use. Expanding every part of your inventory to the limit is a noble goal, but those expensive resources are wasted on things you don’t use. There’s no point in expanding your sling ammo pouch if you’ve never fired a single bomb.Create jobs for yourself. At the bottom of the crafting screen, you’ll see the option to create a job. A job turns your resource requirements into a quest. This will save you a lot of time, frustration and confusion by turning your goal into a shopping list that’s right there on your HUD all the time.Making potions and trapsThe last things you can make from all of that stuff you’re carrying around are potions and traps. They’re a little less obvious than ammo or your inventory, but they’re still important.Running out of resources while crafting resist freeze potions.All of those plants you pick up can become resistance-buffing potions, and all of that meat you’re carrying in your pockets can become health potions. If you’re picking up everything and hunting (like we keep saying you should), you’re going to have all the resources you need to fill your potions pouch several times over. That’s a good thing.Traps deal a lot of damage when you remember to use them.Traps are mines that you can plant for an unsuspecting machine to step on. This is a useful (and fun) way to start a fight. Traps are more expensive than potions, requiring some of the same resources as your ammo.Don’t forget to use potions. We’re bad at this, but potions can turn the tide of a fight either as a buff against a machine’s elemental attack or by taking the burden of keeping you alive off of your medicine pouch.Don’t forget to use traps either. We’re also bad at this, but that explosive start to a fight — especially if you match the trap’s elemental damage to the machine’s weaknesses — can make a fight much, much easier.Sell them to merchants. You’re not going to get rich off potions and traps, but they’ll get you back on your feet if you run out of cash.Merchants and tradeSome resources aren’t for crafting — things like the various machine lenses and hearts. You’ll use these when buying stuff from merchants because most everything a merchant sells has a price in scrap plus resources.You can find merchants everywhere, but they each sell a different assortment of things.Merchants are the only place to pick up weapons and outfits, so you’ll be visiting them a lot. This is why we recommend keeping a couple of everything — every heart and lens and canister — in your inventory for a rainy day. The next merchant you visit might be selling an awesome new outfit that requires one of those hearts you’ve been hoarding.With that in mind, you’re going to hit a point where you no longer need every lens, heart and skin you’ve found. When you find that you haven’t seen a new outfit in hours or that you’ve got slot after slot full of watcher lenses, it’s probably OK to turn (some of) that stuff into shards.Don’t forget about buy back. You can buy back the last several things you sold from any merchant. This is your undo option in case you sold something that you really need (or want) now.Make jobs for stuff to buy. Just like crafting, you can turn your merchant wishlist into a quest.