Guide:Inventory management
This means the page will walk you through a specific task, strategy, or enemy/boss fight.
Keeping your inventory organized is very important when exploring in Terraria, as the goal is usually to fill your inventory with as many valuable items as possible. In general, the key to inventory management is the ability to tell valuable loot apart from junk.
While some loot objectives can be obvious (such as Golden Keys in the Dungeon or Souls of Light in the Underground Hallow), keep your eye out for unexpected valuable items. For example, if you come across a valuable Heart Statue but your inventory is full, you must decide what to throw out in order to make room for it.
The following guidelines will help you decide what to bring and what to keep on your adventure. Consider favoriting items if you decide that they deserve a semi-permanent place in your inventory; this will allow you to use "quick stack" and "deposit all" more freely.
Mandatory Items
These items are a near-must for your inventory in some form or another if you plan to do any serious exploration. Without them, many important activities become extremely inefficient, if not impossible.
Weapons
Weapons are a player's primary means of self-defense, and in order to cover as many different combat situations as possible, it is recommended to carry a variety of them in your hotbar. Later in the game, it is better to specialize towards one of the four primary damage types (melee, ranged, magic, and summon) to conserve space but also that most Hardmode-accessories are not multi-class. If possible, use weapons that can attack from a distance, hit through walls and/or that can damage multiple enemies and be sure to bring enough ammo if using ranged weapons. Summoning weapons can contribute to any character's DPS, even without a dedicated armor set or minion buffs.
To reduce inventory clutter, it is important to know when to retire certain weapons. For example, the Snowball Cannon is a phenomenal weapon in the early stages of the game, but it will see little use after you obtain a Demon or Tendon Bow. If one is not going to multi-class, it is up to the player if they wish to carry a spare weapon or two for the two main combat-classes they do not utilize. Doing so may take up to 2-3 extra inventory spaces max but ensures they may be able to keep fighting in a tough situation, especially with mages to happen to periodically run out of mana.
Pickaxes
Pickaxes are a player's primary means of interacting with the environment and Terraria ensures that you have access to a Pickaxe from the very beginning of the game. You only need one Pickaxe in your inventory, and it will generally be the one with the highest power you have access to but there are several viable exceptions that trade away pickaxe power for mining speed, such as the Bone Pickaxe and Shroomite Digging Claw. (Desktop, Console and Mobile versions) Reaver Shark can only mine up to Demonite/Crimtane.
Light Sources
Lighting usually comes in the form of Torches. Glowsticks, Light Pets, Shine Potions, and the Mining Helmet can be used as substitutes, but unlike Torches, they will not permanently illuminate an area. Shine Potions or Mining Helms may still have some level of utility even into Hardmode, whether to conserve inventory space or to trade shine potions in place of torches for more intuitive exploring without having to stop. Stacks of Wood and Gel can be carried to craft Torches on demand. (Desktop, Console and Mobile versions) If one wants to pay any attention to the Luck mechanic, Bone Torches are a good general non-biome choice instead of normal torches as they supply +0.5 torch luck.
Recommended Items
It is highly recommended to carry these items if you have them.
Blocks & Platforms
Aside from modifying the terrain, blocks are useful for blocking the paths of enemies or even trapping them. All blocks are equally useful for this purpose, but dirt, stone, and mud are likely to be the most plentiful. However, this does not mean they are infinite, dirt and such are finite in a world despite that ((Desktop, Console and Mobile versions) Dirt is however renewable with Dirt Bombs). In a pinch, Wood can also be used this way but be sure to reserve some Wood for crafting Torches and Work Benches if you need them.
Platforms can be used to quickly build arenas, and are useful to climb to high places early in the game (such as searching for sky islands) when mobility is still limited. A stack of Wood or Ice Blocks can be crafted into platforms by hand, and the extras can be crafted back into blocks, so it is not strictly necessary to dedicate an inventory space to them.
Blocks can be also used to dupe liquids, for self-made fishing spots or otherwise via using a 'U shape' and hammering either top block then holding left-click with a bucket right above the hammered block.
Explosives
Bombs and Dynamite, especially when crafted into Sticky Bombs or Sticky Dynamite, are a relatively plentiful and speedy way to excavate large areas. Early on, they can also be used to bypass certain requirements, meaning that they can be used to mine Crimstone/Ebonstone (Desktop, Console and Mobile versions) but they cannot be used to mine Meteorite, however.
Grappling Hooks
On the 
Desktop, 
Console, and 
Mobile versions, Grappling Hooks have their own equipment slot, and as such, they do not interfere with inventory management. On other platforms, the mobility that hooks provide can be used to escape dangerous situations and navigate the terrain, making them well worth the single inventory space that they take up. There is no need to place them in the hotbar.
Informational Accessories
Informational Accessories provide extra information that can be useful during exploration, but the most valuable ones are the Platinum/Gold Watch, Lifeform Analyzer(Desktop, Console and Mobile versions), Metal Detector(Desktop, Console and Mobile versions), and Mechanical Lens(Desktop, Console and Mobile versions).
- While not strictly necessary into Hardmode, the Cell phone can compartmentalize its components and save players several inventory spaces that could be otherwise used for extra equipment or loot.
- Watches tell you the time, which allows you to plan for events such as boss fights. Lower-tier Watches also work (despite being less time-accurate), but only the Gold and Platinum Watch can be combined with other informational accessories.
- Rare creatures often have valuable drops, and some of them are also very dangerous. The Lifeform Analyzer (sold by the Traveling Merchant) provides advance warning of their presence.
- The Metal Detector (dropped by the Nymph) alerts you to the presence of valuable loot, such as Chests, Life Crystals, and Life Fruits. However, it is less useful if you are also using Spelunker Potions.
- The Mechanical Lens (sold by the Mechanic) highlights wires on the map, which alerts you to the presence of naturally-generated traps. Like other informational accessories, it can be toggled on and off at will.
- The Grand Design(Desktop, Console and Mobile versions) provides the same utility as the Mechanical Lens, and can also disarm traps with little effort.
- Any mechanism, such as a Dart Trap or Pressure Plate, can be selected in the hotbar to highlight wires, but doing so is labor-intensive.
Home Teleports
The Magic Mirror, Ice Mirror(Desktop, Console and Mobile versions), Cell Phone(Desktop, Console and Mobile versions), Shellphone (Desktop, Console and Mobile versions) or a Recall Potion will instantly return you to your spawn point. Recall Potions work with no delay, making them more suited for Hardcore or Mediumcore characters who need to quickly escape a nasty situation. Those who are quick with their reflexes can simply activate the Magic Mirror from the inventory screen when needed, saving a hotbar slot for something else.
An alternative means of escape is the Rod of Discord.
Healing Potions
Healing Potions are one of the main methods of restoring health in dangerous situations and should be used frequently, as they are obtained in plentiful supply from bosses and naturally-generated Chests. If you have lost more health than your best healing potion would heal for, use one. They can be activated from the inventory with a hotkey. Honeyfins are a viable alternative pre-Hardmode, assuming one wishes to take the time to fish a supply up.
Portable Storage
A Piggy Bank, or ideally a Money Trough(Desktop, Console and Mobile versions), acts as a personalized, portable storage box. Piggy Banks can only be placed on flat surfaces like a Work Bench or Platforms, but the Money Trough can be summoned anywhere. It is recommended to use the Piggy Bank to store money and items that you use regularly but infrequently, such as Fishing Rods. A Safe can provide extra storage should you need it, and can itself be stored in the Piggy Bank, freeing an additional space. If not using the Money Trough, be sure to pick up your storage items after you are done.
(Desktop, Console and Mobile versions) The Defender's Forge was introduced in 1.3.4 and not only does it add much further storage-capability on the go, its cheap medal-price means it is relatively accessible early to mid-game. (Desktop, Console and Mobile versions) There is also the Void Vault and Void Bag, the latter being very useful because it can pickup items when the player's main inventory is full.
Potions
Several potions are useful and are worth taking up a couple of inventory slots:
- Spelunker Potion (highlights valuable items on screen)
- Hunter Potion (highlight threats and help you to avoid being taken by surprise, especially by Worms)
- Shine Potion (provides a source of light that follows the player closely)
- Obsidian Skin Potion (provides lava-immunity, useful for Cavern/Underworld depths)
- (Desktop, Console and Mobile versions) Potion of Return (useful for inventory management, one can use one and return to base to clear out inventory/restock/etc)
Extra Armor
Apart from the armor equipped in your armor slots, there is some merit to carrying around extra armor sets in the inventory. Several sets, notably Crimson and Palladium armor as well as the individual pieces Squire's Great Helm(Desktop, Console and Mobile versions) and Valhalla Knight's Breastplate(Desktop, Console and Mobile versions), provide a sizable regeneration bonus and are useful for healing outside of combat. Spectre armor is another useful armor switch as it provides rapid burst healing.
It may also be useful to keep a Mining Armor set (or other mining-speed boosting gear), Mining Potions and/or an Ancient Chisel, whether in inventory or in a piggy bank/safe.
Profitable Items
Notes:
- (Desktop, Console and Mobile versions) Making ore into bars (with the exception of Silver, Meteorite and Hellstone) is no longer profitable as now the equivalent ore-amount required for a single bar now sells for the price of their ingot-version.
- Gems, especially lower-tier gems, are not very profitable past early-game. Rubies can be used to craft Slime Crowns, and the Diamond Robe, Ruby Staff, and Diamond Staff are decent in Pre-Hardmode, but aside from those, most gems can be tossed away with no regrets, especially if you have no need for a Gem Hook. Silt/Slush and Gemcorns are an alternate means of getting gems.
Any Progression Level
Gems
One should consider keeping gems as every gem except for Diamonds can be made into Stained Glass. Even with the least valuable gem (Amethyst), this nets a profit of 15 SC per Amethyst compared to selling 20 Amethysts by themselves. If one reserves any gems found from extended spelunking, one can average around 3-5 PC in profit. (Desktop, Console and Mobile versions) For even easier profit, gems are renewable via Gemcorns.
Oysters
(Desktop, Console and Mobile versions) Oysters can be very profitable if sold in bulk via opening them and selling whatever contents obtained. The guaranteed Shucked Oysters can be profitable (netting almost 20 GC per 99-stack) while 2-5 White Pearls or 1-3 Black Pearls tend to be more profitable per full stack of oysters, if a player is saving Pink Pearls for the best luck potions.
Crates
Crates are a good money-source even well into Hardmode. A large stack of crates can net significant profit, massing into the value of multiple Platinum.
Early to Mid-Game
Cobwebs
Cobwebs can provide a large amount of easy profit well into mid pre-hardmode via mass-crafting them into Silk and once the Dungeon is accessible, it is better to use Cobwebs with Bones to make Necro Helmets.
Lens, Rotten Chunks, etc
Boss and event-summoning materials such as Lens, Rotten Chunks/Vertebra, Tattered Cloth etc can be stocked up to make into boss/event summoning items, which allow far greater profit than if one was to sell said materials by themselves. They still have utility even in Hardmode as Lens, Iron Bars, etc are still used for the mechanical-boss summoning items.
Mid-Game to End-Game (Pre-Hardmode)
Obsidian
Obsidian can be more than mildly profitable, especially if kept in bulk. Obsidian Skulls not only are required for multiple accessories including the Ankh Shield but are the most profitable option if mass-mining Obsidian for money and good modifiers can slightly increase profit. The Bottomless Lava Bucket and Bottomless Water Bucket can provide a renewable source of Obsidian.
Others
Whether you wish to bring the following items with you is largely up to personal preference. They can be stored in a Piggy Bank to save inventory space.
- The Bug Net is useful for catching Critters, including those usable as Bait. Bait is particularly plentiful in the Jungle, and aside from that, you will need a Bug Net to catch Truffle Worms. When at your base, it is still useful to have the Bug Net so you can catch critters to sell for pocket change, which adds up over time. (Desktop, Console and Mobile versions) Ladybugs extend the Bug Net's usefulness as Ladybugs are used in all three luck-potions.
- A Fishing Rod can be brought along to gather potion ingredients, Crates, and even equipment items, depending on the biome. A Cooking Pot may also be taken with you so you can craft Cooked Fish on demand. Crates can provide ore/bars on demand without having to spelunk for them, including Cobalt/Palladium/etc post-Hardmode.
- The Staff of Regrowth is very useful if you find a fully-grown, non-blooming herb underground and wish to extract seeds from it.
- Under a similar context, Flower Boots can provide an easy way of gathering seeds/etc.
- Hamaxes combine the functions of Hammers and Axes, and while neither is really mandatory for exploration and caving, hammering can be used to create one-way barriers and perform several other tricks with sloped blocks (see Hoik). Axes can be used to replenish wood supplies in the Underground Jungle, the only biome in which trees will grow underground. The Meteor Hamaxe is the first Hamaxe that players will gain access to, and is fast enough for most purposes while being cheap to craft. Obtaining higher-tier Hamaxes is a relatively low priority.
- Ropes are handy for lining your hellevator(s) and for climbing to high places early-game, but their usefulness is diminished after you gain access to Hooks.
- Water Candles can be placed nearby to increase enemy spawn rates when farming for their drops, especially in combination with a Battle Potion.
Trash?
- Banners are worth relatively little (2 SC) and clutter the inventory. It is a good habit to place them down nearby as soon as you obtain them, unless your goal is to collect them (for decorative purposes or otherwise).
- Common blocks can be trashed if they are not in a large enough stack to be useful for building.
- Herbs can usually be trashed on the spot, as it is far more efficient to farm them at your base. Their respective seeds only need to be obtained once if you are planning to set up a garden.
- Dye ingredients are worth a decent amount of money (20 SC), but can easily be trashed to make room for something else.
- Any item that doesn't seem immediately useful and does not have "material" listed in its tooltip can be safely thrown away. Silt and Slush are exceptions, as they can provide valuable items when fed to an Extractinator.
Tips
- After looting an underground Chest, you can take the chest with you for extra storage at your base.
- This has the added benefit of allowing the Metal Detector to display something other than "Chest detected nearby!"
- If you don't have the heart to throw away some items, you can deposit them into naturally-generated Chests or a dedicated base 'junk-chest' and come back for them later.
- If you encounter a Skeleton Merchant(Desktop, Console and Mobile versions), you can sell your accumulated junk items to him rather than throwing them away.
- The Encumbering Stone is a must for managing your inventory, as holding it prevents you from picking up items that would otherwise clutter your inventory. Simply remove it when you need to pick something up, and place it back when you need to manage space.
- Renaming your chests to match the types of items they store, for example "Ores and Bars", "Potions", "Weapons", etc. will make finding your items much easier.
- Many common items are also used as ammo, and can be stored in your Ammo slots. These include Gel, Fallen Stars, Sand, and in Desktop, Console, and Mobile, Bones, Wire and Bait.
- Extra accessories that you pick up can be stored in your Social Slots, though they may affect your appearance if not having vanity slot(s) hidden.
