Guide:Game progression

This page summarizes the game progression in text form. It will give tips for control of the transitions in the game, and note key items to craft or find (beyond the next tier of weapons and armor). Some tips will represent opportunities for "sequence breaking", by gaining equipment slightly in advance of the "usual" timing. For a more detailed and graphics-heavy guide, see the Walkthrough Guide. For details about strategies for each specific boss fight and/or event, see their respective guides.

Terraria is a sandbox game, but that does not mean it is without structure or change. The game progression presents a cyclic pattern:
 * 1) The player explores a new (or changed) section of the world. This area offers new dangers, especially new enemies, but those enemies also drop new resources. The environment will also offer new items, including local chests with rare items.
 * 2) The player uses these to upgrade their equipment, until they are ready for...
 * 3) ... a boss fight, with occasional events for variety. Each new boss and event provides a uniquely-challenging fight.
 * 4) * Defeating the boss or event provides still more advanced weapons, equipment and materials.
 * 5) * New NPCs may appear, and existing NPCs can sell new items.
 * 6) * Once a player has defeated each boss or event for the first time, it can later be re-summoned for more drops, thus becoming a potential resource.
 * 7) The items gained from the big fight will again improve the player's equipment, but will also present a new challenge, such as access to a new area, or new enemies in a previously explored area. This returns the player to step 1.

Several bosses are particularly significant for game progression:
 * The Wall of Flesh will trigger Hardmode in the world when defeated. Both the environment and the enemies encountered become far more hostile and dangerous after this point.
 * Defeating Plantera opens access to many different locations and challenges, which all serve in preparation for the late game.
 * The Moon Lord is the last of the "mandatory" bosses for most versions. ( have Ocram instead.) Defeating them is the minimum standard for "beating the game". However, this being a sandbox game, that's not a "game over"!  From this point on, the player is in the "endgame", where they can continue to gather resources and equipment, build projects, and test themselves against various optional challenges.

Getting Started
The Player starts with minimal equipment. Your task at hand is to collect resources, build a base, and craft better equipment. You'll start off chopping Trees for wood, killing Slimes by day, and digging around the surface of the world.


 * You need to make yourself a base before night.


 * Make better armor, weapons, and tools as you gather materials.
 * Make a Bed as soon as you can, and set your spawn point in a safe house.
 * Start mining Underground.
 * As in most adventuring games, collect everything you see -- almost everything is useful, able to be sold, or both. Fairly soon you will be able to find and/or make chests to stash extra items.

Items

 * Once you get the Merchant, buy a Piggy Bank and a Bug Net as soon as you can. When you can afford it, a spare piggy bank or two will come in handy.
 * Collect Fallen Stars as you find them. Until your mana is maxed out, make Mana Crystals and use those immediately, afterwards bank the stars for later use -- they are important for a variety of crafting recipes.
 * Collect all the Heart Crystals you find, but don't actually use them until you're ready (see "Tips" below).
 * Use the Bug Net to collect all the critters you can. You can sell most of them for silver (and in some cases gold), but hang onto the worms (and anything with a better bait value) for later fishing.
 * In 1.4, a fair number of critters can be cooked into food at a Cooking Pot. Food comes in three tiers now:  Bunnies, squirrels, and most birds can be turned into basic food, providing the Well Fed buff.  However, keep an eye out for those critters whose cooked form can provide the more powerful Plenty Satisfied buff:  Goldfish, Snails, Ducks, Frogs, and jungle bait (you need all three kinds, Buggy is the rarest, Sluggy is next, and Grubby is common).  Any Golden Critter (including those which aren't usually edible) can be turned into a Golden Delight, which can be sold for the same (high) price as the critter, or eaten for a full two game days of the top-tier Exquisitely Stuffed buff.  When you get into fishing (see below), various fish you catch can also provide all three tiers of food, and probably in greater quantities.

NPCs

 * Nearly all NPCs need a house: as the population grows, housing them all and defending them will become an increasing issue. The NPCs can defend themselves fairly well against individual early-game enemies, but later in the game or if they get mobbed, they can be killed (they will respawn, but not immediately). In general you should always have a spare house or two available in case you happen to meet the standards for a new NPC to arrive.
 * Some NPCs may not seem very useful, but there are purposes for which any NPC will do:
 * Some NPCs will appear only once a certain number of NPCs have already appeared or other conditions have been met (such as the player carrying some related item in inventory).
 * Enemy spawns are reduced near any NPC. If three NPCs are visible on the screen, enemy spawns will be completely suppressed (except during events like Blood Moon).
 * Any NPC that can sell items can also buy items from the player. Any NPC who buys items, can buy any item, and all will offer the same price.
 * Make sure your NPCs are happy! Their happiness makes their prices fluctuate greatly. Building them a large house and letting them live in their favorite biome, near their favorite neighbours, pays off.
 * Happy NPCs will sell Pylons, which are extremely useful for quick transportation. You need two NPCs near each pylon (happiness not necessary) to use it.
 * While NPC happiness is currently only available on Desktop platforms, setting up NPCs in biomes they will like once 1.4 reaches other platforms can pay off, as you dont have to deconstruct a large NPC town or go through the hassle of mass relocation of NPCs.
 * The Zoologist (see below) will eventually sell Pets, which count as NPCs for pylons and for reducing enemy spawns. They also make nearby NPCs happier.
 * You start with the Guide, you just need to build a house for him. He can give advice about crafting and occasional warnings of upcoming events.
 * Carry at least 50 silver for the Merchant. He will sell an assortment of basic items.
 * The Zoologist: As you encounter various creatures (critters, NPCs, enemies and even bosses), you will fill in entries in your Bestiary.  Once you reach 10% completion, the Zoologist can arrive.  Her varied wares tend to be expensive, but also very useful and/or entertaining.  She will sell more items as you continue to fill out your Bestiary. She will show up fairly early:  10% of the Bestiary is only 50-odd creatures, each variety of zombie and demon eye counts separately, and your first Golden Critter unlocks entries for all the Golden Critters.
 * Find and carry an explosive for the Demolitionist. He sells grenades, bombs, and other explosive items.
 * The Nurse will appear after you use your first Heart Crystal. She does not sell items, but can instantly heal you and remove debuffs for a small fee.
 * The Stylist is found in a Spider Cave, but will be helpless when found. She'll probably be the first you meet of the several NPCs who need to be found and "rescued" before they can move into your town. Her services are purely cosmetic, but some of her hair dyes can provide information, and she can buy your items.
 * The Golfer is found in the Underground Desert, which is fairly dangerous at the beginning, but you'll get there eventually. His wares deal entirely with the new minigame of golf, but since he's a vendor, so he can buy your excess stuff.
 * There are three "non-town" NPCS, who do not need (or want) a house. These are the Old Man (found at the Dungeon entrance... temporarily), the Traveling Merchant (who will visit during the day) and the Skeleton Merchant (found randomly underground). The Old Man is used only to summon Skeletron for the first time. The other two merchants will each sell a random and/or time-dependent selection of merchandise, and can also buy unneeded items from the player.

Tips

 * Mark the spot where you spawned for the first time, and be careful about digging there. If you dig away the ground at the world spawn, the next time you respawn you will promptly fall into your hole. If you try to build over that spot, blocks will break when you respawn there anyway.  (In 1.4, you have a map marker for spawn, and you can respawn a few blocks higher or lower if something's in the way.  You still need to have someplace where you can stand, but  you can build a shelter there and spawn inside.)
 * Those mushrooms are your first "healing potion". Get in practice! Don't wait until you're almost dead, because you have a 60-second cooldown before you can use another healing potion.
 * Until you start using Heart Crystals, your biggest threats are the night monsters, and possibly King Slime if you wander far enough away from spawn.
 * The first crystal you use will enable Blood Moon nights to happen randomly, while also bringing in the Nurse. You probably shouldn't do this until you've got at least Iron armor and weapons.
 * The second crystal enables Slime Rains, which can bring King Slime to your doorstep.
 * The fifth crystal will cause the Eye of Cthulhu to spawn randomly at night. If possible, work your way up to Gold/Platinum armor and weapons before you use the fifth crystal. If you have more crystals, use them all with the fifth one, you want to be as strong as possible for this fight.
 * You can collect lenses to craft a Suspicious Looking Eye, to summon the Eye manually at your convenience. Watch for messages and comments from the NPCs, so you don't summon him on a night when he'll appear on his own. Similarly, don't summon him at exactly 7:30 pm: wait a few seconds to make sure he's not coming, and that it's not a Blood Moon.
 * When you get killed, you will normally have a tombstone left where you died. Mine and collect these as soon as you can, as they can attract monsters even during the day -- including ghosts, which are fairly dangeorus to a beginning character.  If a ghost shows up when you mine the tombstone, for now you should attack from a distance or run away.  When you have six tombstones, you can make a Graveyard, which will allow you to buy and craft a number of special items.

Seasonal Events
Terraria offers a couple of seasonal events, based on the Gregorian calendar used in the Western world. These "holiday seasons" overlap any normal game events that may be happening and provide additional features.

If it is Valentine's Day in Terraria, the Merchant will sell two particularly useful items:


 * For, the player can buy a Valentine Ring. When dropped, picked back up, and equipped, it grants a jump bonus and a health regeneration boost.
 * For, the player can buy a Heart Arrow. Heart Arrows are basically Wooden Arrows which stun enemies for 1.5 seconds. These can be extremely useful against bosses, especially when used in large amounts. If a large enough amount is used, a boss can be stunned forever.

Halloween
Halloween is somewhat less generous, but does offer some goodies:


 * The Witch Doctor (see below) will sell a Cauldron, a Cooking Pot which is Halloween-themed. This can be a nice alternative than using your own Iron/Lead to make one.
 * The Bloody Machete and Bladed Glove both have a 0.05% drop rate from all weaker enemies. Both weapons are very powerful in pre-Hardmode.
 * Pumpkins will naturally grow around the world. Outside of the Halloween season, they would not be available until the Dryad appears. Pumpkins can be used to make Pumpkin armor, which is as good as Tin armor, plus the set bonus boosts all damage by 10%. They can also be used for Pumpkin Pie, an excellent food item.
 * Monsters will drop Goodie Bags. These mostly contain costume sets, but also can include Rotten Eggs. These are a weak throwing weapon, but they are the only player-wielded weapon that normally damages NPCs. Rarely goodie bags can also contain the Unlucky Yarn, or the useful Bat Hook. The costumes can also be sold.

Christmas
If it's Christmas in Terraria, you can use Presents to speed up progression:


 * Presents can drop the Red Ryder and Musket Balls for ammo. These are extremely useful early on, and will allow the Arms Dealer to move in.
 * They can drop the Fruitcake Chakram.
 * Star Anises can drop from Presents.
 * Finally, Candy cane tools, weapon and Blocks can be dropped. Candy Cane Blocks can save material when building houses, as they can replace wood in the walls and basic shape of the house. The Candy Cane Sword is a strong mid pre-Hardmode sword, and the Candy Cane Pickaxe can mine Demonite and Crimtane, meaning that you can skip the Gold Pickaxe. The Candy Cane Hook is better than the normal one, and also drops from Presents, making it easier to obtain.
 * The Hand Warmer can also drop from a Present. The Hand Warmer protects against the Frozen and Chilled debuffs when equipped.
 * Presents can be saved for later opening in Hardmode, when they can also contain a Snow Globe to summon the Frost Legion.

Continuing Pre-Hardmode
Once you've beaten the Eye, it will no longer spawn on its own. You should definitely be able to reach the Jungle by now, and go onward to the Ocean (for the Angler).

NPCs

 * The Dryad sells a number of nature-related items, including:
 * Seeds to plant any sort of grass, Sunflowers for a useful buff, Acorns to grow trees, and Pumpkin Seeds to grow pumpkins for another building block.
 * Once you've defeated some bosses, she will also sell Planter Boxes to grow herbs more conveniently. The boxes have names and appearances for each herb, but in fact any herb will grow in any pot.
 * Her Purification Powder can purge Corruption or Crimson from small areas, and is the only way to revert tainted blocks at this point.
 * The Dirt Rod can be useful for dealing with traps or fending off enemies from a distance.
 * Various decorative items
 * The Angler is found sleeping near the Ocean. His quests will provide a trickle of money and a steady stream of useful tools and accessories.
 * Carry any Plant to attract the Dye Trader. He sells dye-related items, including a couple of colors that are not otherwise found in the world, and the crafting station to mix your own dyes. He also trades Strange Plants for unique dyes. From 1.4 and onward, Strange Plants only spawn in Hardmode. Pre-1.4 worlds that were upgraded to 1.4 may already have Strange Plants spawned in Pre-Hardmode; stash these for later use, as the Dye Trader will not trade for Strange Plants in Pre-Hardmode.

Items

 * From here on, use Heart Crystals immediately until your health is at maximum. Once you've used all you can, you can craft them into Heart Lanterns.
 * Make a Reinforced Fishing Pole for fishing.
 * Make a Cooking Pot for cooking fish and critters.
 * Make Clay pots or buy Planter Boxes from the Dryad to grow Herbs as you collect seeds. Place a bottle and start making potions.
 * You will be collecting seeds for 7 herbs from as many biomes: Daybloom (Forest), Blinkroot (underground), Moonglow (Jungle), Shiverthorn (Snow), Waterleaf (Desert), Deathweed (evil biome), and Fireblossom (Underworld).
 * Boots add mobility, and begin the crafting chain ending with Terraspark Boots.

Fishing
From this point on, fish as much as you can: take every possible quest from the Angler, using all the fishing-related equipment and potions you get from him. Continue until you have all the functional rewards: Golden Bug Net, Golden Fishing Rod, Fish Finder, Angler Tackle Bag. On the console and mobile versions, the Angler has a cap of 150 quests, after which all the remaining rewards become much more rare. So once you have all the pre-Hardmode rewards, stop taking Angler quests until Hardmode, when there will be a few new rewards.


 * Until you get Master Bait, Enchanted Nightcrawlers are your best bait. Some butterflies and golden critters are a little better, but those also sell for good money.
 * Fishing will get you an assortment of useful items, both directly and from crates. The Reaver Shark, Sawtooth Shark, and Rockfish will serve you for a long time, while some of the accessories will help you get around and/or protect from falls. Crates can provide the tiny but powerful Falcon Blade, among other powerful items.
 * Set up three chests for quest fish, and each time you fish for one, try to catch four of the current quest fish at a time (stuff them into your piggy bank as you catch them). The next couple of times those quests come up, you can hand over the fish immediately from your chests.
 * When you've got all the crate drops and plenty of metal, start stockpiling Crates, and continue until Hardmode. Biome crates can have special items, mostly the same items as the biome's chests. Crimson or Corrupt Crates will also add special drops in Hardmode, so make sure you keep some of those.
 * In 1.4 versions, crates have been rebalanced, and pre-Hardmode crates no longer yield Hardmode metals if saved to Hardmode. Accordingly, there's no reason to stockpile them.
 * Be wary of fishing during Blood Moons, as you might pull up a monster! (Sonar potions definitely recommended....)  Either a Wandering Eye Fish or a Zombie Merman will make for a tough fight, but the potential rewards are rich, including an early minion.

Once you reach Hardmode, you want the Bottomless Water Bucket, Super Absorbant Sponge, and Hotline Fishing Hook, after which you're pretty much done with the Angler. Fishing in general will remain useful into early Hardmode, but eventually there will come a point when the player has better equipment than anything they could fish up. At this point, fishing is reduced to resupplying potion ingredients and perhaps farming for cash or metals.

The Evil biomes
Once you have Gold/Platinum or better equipment, with some helpful accessories, you should be able to delve into your "evil" biome with relative impunity. At this point, you can start breaking Shadow Orbs or Crimson Hearts (collectively "orbs"). After the first orb is broken, meteorites will begin falling on the world (always off-screen). In 1.4 versions, meteorites will not spawn until the Eater of Worlds or Brain of Cthulhu is defeated for the first time. There will also be a random chance each day of the Goblin Army invading.


 * When breaking that first orb, make sure of the status message you get, which should be "A horrible chill runs down your spine...". If you instead get "Screams echo around you...", this means that one of the orbs has already been broken, by faulty world generation.
 * The first orb always gives you a Gun (Musket in Corruption world and The Undertaker in Crimson world). The second orb broken will offer more drops, but otherwise ought to do nothing in particular.
 * Every third orb broken summons Eater of Worlds (corruption) or Brain of Cthulhu (crimson).

Meteorites

 * In 1.4 versions, meteorites will not spawn until the Eater of Worlds or Brain of Cthulhu is defeated for the first time. Each time the boss is defeated, there is a 50% chance that night of one falling.
 * To minimize meteorites, avoid breaking multiple orbs between midnight and dawn (4:30 AM), as that can get you multiple meteorites immediately (separate 50% chance for each orb broken). If orbs are broken at other times, there will be at most one meteor (next midnight) no matter how many orbs you broke that day.
 * Regardless, once this box is opened, there will be a small chance of meteorites falling every night thereafter.
 * However, no more meteorites will fall if there are already one (small worlds) or two un-mined crash sites.
 * There are also ways to protect particular areas from meteorites:
 * They will never fall on the central sixth of the world, so areas near spawn are safe.
 * They will also not fall within 35 tiles of an NPC or a chest, which effectively protects your towns and most of your bases.
 * They will never fall on-screen for any player.

NPCs

 * Carry Bullets or a Gun (from a broken orb) for the Arms Dealer. He sells Guns, Ammunition, and the Illegal Gun Parts used to craft several powerful guns. Specialized ammunition may not be offered unless you are carrying the appropriate weapon.
 * Tavernkeep, found after defeating your Evil biome boss. He provides access to the Old One's Army event, and equipment to fight it.
 * The Goblin Tinkerer can be found underground after defeating the Goblin Army. He provides several useful services such as:
 * He sells the Tinkerer's Workshop to combine accessories.
 * He sells Rocket Boots, and a handful of other items.
 * Reforging, which is the process by which you can improve an accessory, weapon, or tool by getting a new modifier for the item. Throughout the game, a fair bit of your coin will go toward reforging your equipment for improved power.
 * Painter. His wares are purely cosmetic, but can drastically improve the appearance of your base, not to mention such practical uses as color-coding chests.

Tips

 * From this point on, Meteorites will be hitting your world. Place Chests at all your bases and other points you want to protect, as they will prevent from landing there.
 * Once you have enough Meteorite ore, consider making a Skybridge as a Meteor shield over your world.

The Old One's Army
This is a completely optional challenge which requires a fair bit of preparation, and at this point the direct rewards are mostly minor. However, it's still worth playing through a few of these, for a major weapon and to prepare for the future:


 * The Tavernkeep will give you the tokens for one of his sentry weapons up front, but until you've beaten the Army once, you can't use them outside the event. The Tavernkeep sentries turn out to be remarkably useful in ordinary adventuring, and these are the only sentries you'll get before Hardmode and the Queen Spider Staff.
 * Later in the game, the Old One's Army will progress to Tier 2, where the Ogre drops will be much more useful. Five wins at Tier 1 will let you buy a Tier 2 sentry before you go to fight the Tier 2 invasion.
 * Likewise, a few wins at Tier 2 will let you buy a Tier 3 sentry (perhaps even some summoner's armor) before you fight the Tier 3 invasion.
 * If you like, you can play a few extra times to buy the other Tier 1 sentries, each of which has its advantages.

The Jungle
The main boss here is the Queen Bee, though there are plenty of other dangerous enemies around. The Queen Bee will punish you for leaving the underground or the Jungle, but you don't have to fight her inside her own Hive -- you can run to a prepared arena with more space. She will provide you with what's probably your first minion, various other powerful weapons and accessories, and the makings for the pre-Hardmode summoner's armor.

Items

 * Bezoar, protecting you from the omnipresent Poison debuff. Eventually it will be part of your Ankh Shield.
 * The three Jungle materials: Vine drops (not to be confused with the plants) and Stingers can be had in the underground, but you will need to descend to the Caverns to get Jungle Spores.
 * Hornet Staff, Bee's Knees or Bee Keeper, and other Queen Bee drops.
 * Optionally the Imp Staff (if you detour to the Underworld, which you can handle with the Hornet Staff).

NPCs

 * Witch Doctor (after killing Queen Bee). At this point his most important item is the Imbuing Station, which allows you to make Flasks for melee buffs. He also sells the Blowgun, and as the game advances will provide miscellaneous tools and ammunition.

Floating Islands
If you haven't been to these already, you should be able to get there by now with ropes, minecart tracks, and/or Gravitation Potions. Fall damage is the biggest threat. The Umbrella or Featherfall Potion will prevent you from taking fall damage. You can find Umbrella in wooden chest found in the surface level. Both Featherfall and Gravitation potions can be found in chests, or crafted by players or Pots. (Gravitation potions can also appear in crates.) You will get several unique items from Skyware chests - while fishing can provide other jump bottles and a balloon, there's no substitute for a couple of items here. A Sky Lake will also let you fish for Sky Crate and Damselfish.

Items

 * Lucky Horseshoe -- complete fall protection, and can be combined into a Horseshoe Balloon.
 * A Sky Mill lets you craft skyware items and blocks.
 * The Starfury provides a distance attack that ignores walls (but not all ceilings).
 * The Shiny Red Balloon and/or Cloud In a Bottle -- fishing may have provided similar items, but these versions offer more crafting options.

The Dungeon
By this point, you should have at least Demonite, Crimtane, Meteorite, or Jungle equipment, with a fair range of weapons and accessories. A tough fight with Skeletron will grant you access to the Dungeon. The Dungeon will provide a a Tally Counter to complete your Cell Phone, a Nazar for your eventual Ankh Shield, a Muramasa to complete your Night's Edge, a Handgun to make a Phoenix Blaster, and a Shadow Key for looting the Underworld. It will also provide an Alchemy Table to improve potion crafting, Bewitching Table to let you summon an extra minion, and the Bone Welder and Bone Wand to get some use out of all those bones you've collected. The Mechanic is also rescued here. You should now be able to craft a Void Bag, doubling your inventory by allowing you to continue to pick up items when your main inventory is full.

Items
Cell Phone, Shadow Key, Night's Edge, The Grand Design.

NPCs

 * Clothier: He can supply an assortment of wearables and the materials to make others. All his wares are cosmetic or used to craft other vanity items.
 * Mechanic: She will be your main source for wires, switches, actuators, and other Mechanisms. You can also loot wire, pressure-plates, and traps from the world.

Tips
Clear the place out as best you can, fixing obstacles and stripping away Spikes as you go. (Note that spikes only hurt players, so using them elsewhere is pointless except maybe in PvP.) You might also want to make a fishing hole here for later; remember, to fish for Dungeon Crates you must be below Surface level and in front of "natural" Dungeon wall. In 1.4 versions, areas of the Dungeon are blocked off by brittle blocks that are destroyed by walking or grappling on them. Therefore, it is a good idea to use a Dangersense Potion to see where these blockades are so you can safely remove them and discover every room in the dungeon.

The Underworld
Explore and loot all the Underworld's Ruined Houses and loot the Shadow Chests, while mining Hellstone for Molten Armor and other equipment. You will also begin to make several kinds of preparation for Hardmode, see below. Build bridges over the lava, especially in the central area with the Ruined Houses.

Items

 * Imp Staff
 * Demon Scythe(rare)
 * Fireblossom seeds
 * Shadow Chests may contain the normally mid-Hardmode Drax. If you find one, keep it handy, as it will be very useful even in late Hardmode.

Lava Fishing
Fishing in lava can yield some quite powerful items, especially useful in the Underworld. To fish in lava, you need one of: a lavaproof fishing pole, a lavaproof hook (accessory), or Underworld bait. Note that you do not need to actually be in the Underworld, you can adopt a lava pool in the Caverns, or make your own at your base.


 * If you wait until Hardmode, the Angler will eventually give you the Hotline Fishing Hook, which despite its name is a fishing pole. If you don't want to wait for that (and you're on a 1.4 version), you can catch Underworld bait:
 * Catching Underworld bait requires a fireproof net; the Golden Bug Net will work, but if you don't have one, you can gather some extra Hellstone to upgrade a regular bug net into a Lavaproof Bug Net. Magma Snails are best, followed by Lavaflies, but Hell Butterflies also qualify, and in any case at first you'll get whatever you can find.
 * Once you have some Underworld bait, do your best to max out your fishing power and luck, and fish for Obsidian Crates. Eventually one of these will contain a Lavaproof Fishing Hook.  Unlike the Hotline rod, this is an accessory that will let you fish in lava with any rod or bait -- arguably superior to the other options, since you can use your Golden Fishing Rod and Master Bait.
 * Once you can fish for Obsidian Crates, try for a Lava Charm if you don't have one already -- with Water Walking Boots from the Ocean and some obsidian, you can upgrade your Frostspark Boots to Terraspark Boots, which let you casually walk on lava (or water or honey), and even protect you for a few seconds from an unexpected dunking.

Late Pre-Hardmode
At this point, you should be more-or-less master of all you survey, able to casually slaughter the worst of the pre-Hardmode enemies and bosses. That will change in Hardmode, but with no new threats incoming, you can take some time to do projects and large builds, and especially to prepare your world for Hardmode:


 * Make sure you have spare houses scattered across the map, in case some of them get swallowed by the Evil biome, and set up some secure fishing spots in each biome.
 * Try and fill out your map as much as possible, including locating the Jungle Temple and finding all the Biome Chests in the Dungeon. Exploring in early Hardmode will be a difficult task until you obtain decent weapons. Unlocking more of your map will also let you see how the evil biomes are affecting your world in Hardmode.
 * In 1.4 versions, it is a good idea to set up Pylons across your world if you have not done so already, as doing this in early Hardmode will be a dangerous and difficult task. Note: when Hardmode begins, some of the Pylons will not work if their biome is taken over by the world Evils, at which point you must relocate your NPCs to a purified area.
 * Reshape the landscape as you like -- if any ravines or mountains are annoying you, now's the time to do something about them.
 * Try and obtain all the pre-Hardmode fishing rewards, both from crates and the Angler. In 1.4 versions, stockpiling crates for Hardmode is no longer effective, as they only yield pre-Hardmode rewards.
 * Check your crates, you'll want to go into Hardmode with at least a stack or two. Two full stacks of wooden crates and at least some "Evil" crates will pay big dividends by (hopefully) letting you skip altar-breaking later.
 * Stock up on potions, because you'll be wanting those more in Hardmode. If you haven't already, set up a farm for all seven herbs.
 * If you haven't already, make a surface Glowing Mushroom biome, and build a house there for Truffle to move in later.
 * If you haven't already, construct a basic arena with platforms, campfires, and heart lanterns. This will help you throughout Hardmode and will also prepare you if a Pirate Invasion occurs very early in Hardmode.
 * It may be a good idea to set up an underground AFK farm so you can quickly obtain some good weapons at the start of Hardmode.
 * Prepare your bases with defenses against the future Hardmode enemies. You'll be dealing with more powerful jumpers, and a number of enemies that can move through blocks.
 * You can chop up your world with "hellevators" and tunnels, to block spread of the Hallow and Crimson or Corruption. Especially try to protect at least some of the Jungle and your spawn base. Note that for Desert in particular, you will want all three sorts of desert on the surface and underground:  Evil, Hallowed, and "pure".  You should also take measures to protect at least one of the ocean shores.

Prepare the Underworld for the Wall of Flesh fight: Having established a safe surface to walk on, place stations along the way with Heart Lamps, Campfires, Stars in Bottles, Peace Candles and banners, trying to cover as much territory as you can with your protective buffs.


 * Before version 1.4, a somewhat extreme way to prepare large parts of the Underworld is to flood it, by digging Hellevators down from either or both of the oceans. This won't help much with the middle part covered by the Ruined Houses, but in a small world it will cover most of the lava of the outer third(s) in obsidian before the water evaporates.  By now you also have the equipment to refill the oceans afterwards (eventually).  Note that this is a major project in its own right, needing at least one Hellevator from the underworld to the surface.  Warning:  As of version 1.4, the old liquid duplicators will no longer work!  Flooding either side of Hell will basically sacrifice the ocean on that side, and you have little hope of refilling it until you get the Bottomless Water Bucket from the Angler in Hardmode (and even then, it will be a much more involved and tediious process than before).
 * In 1.4, you may be better off relying on an upgrade of Water Walking Boots -- if you can upgrade them up to Lava Waders, you can now combine them with your Frostspark Boots to get Terraspark Boots.

Finally, gather up your best weapons and armor, choose your accessories, grab a few bags of Purification Powder, and summon the Wall of Flesh. When you defeat it, look around for a Tortured Soul to purify into your Tax Collector.

Note that for the moment, the Underworld is probably safer than most other places -- the only new enemy you'll see in the underworld is mimics, and while those are still tough, they are also "good hunting" with worthwhile drops.

If you want to dare heading up the long way instead of teleporting home, keep an eye out for a Wizard to rescue, and if you meet the Skeleton Merchant be sure to pick up some yoyo equipment: A Yoyo Glove (and a Counterweight if you don't have one yet to make a Yoyo Bag.  If you didn't pick up a Hel-Fire in the Underworld, you might buy a new yoyo from him too --  A Gradient if you can (full moon to waning crescent) or a Format:C otherwise.  While you're at it, you might pick up a Slap Hand too.

Early Hardmode
After killing the Wall of Flesh, the world moves into the "midgame". At this point, much of the world has probably been mapped and looted, including all the surface biomes and most of the large structures (except the Lihzard Temple, which has at least been located). But the monsters are a lot tougher in all environments, the contagious biomes are trying to take over the world, and big chunks of previously-known territory have been taken over by evil or the Hallow. Additionally:


 * Rain brings Angry Nimbuses and their Nimbus Rod.
 * Goblin Armies now include Goblin Summoners, which drop Shadowflame weapons;
 * Underground, the rare Biome Mimics are a tough challenge with awesome rewards;
 * Chlorophyte will start appearing in the Jungle, but you can't mine it yet ( unless you found a Drax in a Shadow Chest).

If you insist, you can get the Hardmode metals from fishing for Crates, but that will take a while --- as of 1.4 you need to do that in Hardmode, and you will need to get hundreds of crates while the biomes spread over your world.

Otherwise, it's back to the normal method of "chaining up" to get the first few tiers of Hardmode metals. Note that the ore counts below are the minimum for chaining up, you will certainly want more for weapons and armor.


 * 1) Use the Pwnhammer you got from the Wall of Flesh, to smash at least three Demon Altars.  You can smash more to get more ore, but diminishing returns set in fast, and for each altar smashed, a random block in your world has the chance of being converted to either the Hallow or evil biome, potentially starting a new infection (perhaps in an unexplored area where it can spread freely).  Destroying 12 altars will roughly double the ore provided by the first three, while quadrupling the hazard from these seed blocks.  Watch out for the Wraiths that spawn!
 * 2) Use your Molten Pickaxe to mine for at least 45 Cobalt or 54 Palladium ore.  Use your furnace (it doesn't have to be a Hellforge yet) and anvil to make a Cobalt or Palladium pickaxe (or drill, as you prefer) which can mine the next tier of ores.
 * 3) Use that pickaxe/drill to mine for at least 100 Mythril or 120 Orichalcum ore.  Use your furnace to smelt some of it into bars and make a Hardmode Anvil, then use that to make a new pickaxe/drill, which again can mine the next tier of ores.
 * 4) Use your newest pickaxe/drill to mine at least 30 Adamantite or Titanium ore, and use that to upgrade a Hellforge into a Hardmode Forge.  This will let you smelt the rest of your new ore into bars; you don't need to make a pickaxe out of it, so get started on weapons and armor.

At this point, you should try to kill the first Mechanical Boss as soon as possible (to get the Steampunker and her Clentaminator) and perhaps push onward to killing Plantera (which will drastically slow down the infections). How important this is will depend on how well you prepared your world, but in any case, The Hallow and infectious Evil are now part of your game.

NPCs

 * Truffle will show up if you have a suitable house for him in a Surface Mushroom Biome.
 * Many of your existing NPCs will have new items for sale.
 * The Merchant sells the Disco Ball.
 * The Demolitionist sells Hellfire Arrows and Explosive Powder.
 * The Dye Trader gives several new Dyes. Strange Plants will begin to spawn around the world, which the Dye Trader will trade for the various "quest dyes".
 * The Dryad sells Hallowed Seeds and Jungle Wall.
 * The Arms Dealer sells the Shotgun and Empty Bullet Shells. Unholy Arrows are now available around the clock.
 * The Stylist sells Biome Hair Dye.
 * The Witch Doctor sells the Tiki Totem pet and Leaf Wings (He must be placed in a house in the Jungle for these two extra items to be available)
 * The Mechanic sometimes sells the Mechanic's Rod.
 * The Party Girl sells Firework Rockets, Bubbles, and Smoke Blocks.
 * The Traveling Merchant can occasionally sell the Gatligator.
 * The Skeleton Merchant can sell two new Yoyos, the Yoyo Glove (to complete your Yoyo Bag -- need a Counterweight too), and the Slap Hand.
 * Tax Collector. If you didn't catch him on the way up from the Wall of Flesh fight, go get him now for a steady stream of money.
 * The Wizard: Along the way, look for the Wizard in the Caverns or below. Once rescued, he will sell you the Crystal Ball and Ice Rod, along with key materials for several weapons.

Items

 * A Hardmode Anvil and Hardmode Forge, and a Mythril or Orichalcum pickaxe or drill.
 * Basic Hardmode metals. As with the pre-hardmode ores, only one of each tier can appear in the ground as ore. Crates can provide all six metals.
 * Most of the Hardmode armor sets each have two or three variants. Each different piece provides different set bonuses to favor a particular class . Summoners are represented by "themed" sets and Tavernkeep armor.
 * A Pocket Mirror will defend agains Medusa's petrification, possibly the most deadly single attack in the game at this point. A Medusa Head isn't the "instakill" it was against Wyverns and the Destroyer, but it's still a powerful magic weapon. Given the hazards of hunting Medusa in the wild, the statue farm with lava is definitely the way to go.
 * Wings: Most wings are crafted with 20 Souls of Flight (gained by slaying Wyverns) plus one or two "key" ingredients determining the type of wings you'll craft. A few types can be purchased, which saves you from hunting Wyverns.  The Wing progression has changed a lot in 1.4:
 * If you have some money you can buy a minimal set from from the Witch Doctor, or you can get a equivalent set of Demon or Angel wings by farming 25 Souls of Night or Light, plus 20 of Flight. Or else you can wait a bit for one of the many other options.  (Before 1.4 the Leaf Wings were more expensive but also much more powerful.)
 * You might already have gotten a Giant Harpy Feather, which will produce a solid second-tier set of wings.  An Ice Feather from an Ice Golem will do as well, or collect 100 pieces of Pixie Dust.  The Fin Wings from the Angler will save you the Wyvern-hunting.
 * Once you beat one of the Mechanical Bosses, you get better options: The Steampunker's Jetpack is a step up, but still better wings can be crafted from rare drops, from Moss Hornets or Moths in the Jungle, or Red Devils in the Underworld. Later stages of the game (Plantera, Golem, optional bosses) will similarly unlock even more powerful wings.
 * Black Recluses: The Spider Caves you've already found will now be spawning Black Recluses. Use some of your new weaponry to kill them for their fangs. You'll at least want enough for the Spider and Queen Spider staves. If you're a Summoner, you may want to craft the Spider armor.
 * Mounts: The Ancient Horn or Blessed Apple both give you good mounts for charging through mobs, but the Scaly Truffle will let you move fast and fly.
 * Ankh Shield: This is a long-term project, which will likely extend through coming stages. You should already have an Obsidian Shield by now, and a couple of the other ingredients (Bezoar and Nazar).
 * If you don't have any of those, go get them. For the shield, if you've run out of golden chests in the Dungeon, fish for Dungeon Crates.
 * You will be collecting nine rare drops of widely scattered monsters, to combine with each other and the Shield. The result will be a single accessory to protect you from a dozen of the most common debuffs and other hazards you'll encounter while adventuring.
 * Armor: You will probably want armors made with the new Hardmode ores. Palladium and Titanium armors have very good defensive set bonuses, while Adamantite and Orichalcum armors are better offensively. A summoner may prefer Spider armor or the armor that the Tavernkeep sells instead.
 * Biome Key s (Biome Key Molds ): These will be rare drops from any enemy in certain biomes: You will want to collect them from five biomes (four before 1.4) before returning to the dungeon: Jungle. Snow, Hallow, Desert, and whichever Evil biome you have.

Fishing
There are a few new catches and Angler rewards:


 * Rewards: The Fin Wings, the Hotline Fishing Hook to fish in lava, the Bottomless Water Bucket and Super Absorbant Sponge for water handling.  Once you have these, you are pretty much done with the Angler, but can still fish for your own reasons.
 * Potion fish: In the Hallow, catch Chaos Fish (Teleportation potion), Princess fish (Love potion), Prismite (Lifeforce potion).  In lava catch the Flarefin Koi and Obsidifish for the Inferno potion.
 * Items: Bladetongue or Toxikarp from the evil biome, Crystal Serpent from the Hallow, all of them are decent weapons.  Scaly Truffle where any of the above overlap the Snow biome.  The Obsidian Swordfish is a short but deadly spear caught in lava.
 * Crates: You will now be catching Hardmode versions of crates, with the Hardmode metals and a few extra items.
 * Enchanted Sundial: From non-biome crates, this lets you skip the occasional invasion, Blood Moon, or Solar Eclipse.

Tips

 * Evil crates fished up after entering Hardmode can now contain Souls of Night and Ichor or Cursed Flames, which are vital ingredients in several powerful Early Hardmode crafting recipies.
 * Keep in mind that Wraiths will spawn when you break altars, and random parts of the world can be infected.
 * Maintain world purity: At this point, the evil biome will spread thrice as fast even over grass, and will also corrupt Stone blocks and Sand, so Sunflowers can no longer stop it from spreading. Additionally, the Hallow starts to spread over the world.

The Pirate Invasion
Even if you have not broken any altars, you can still manually summon a Pirate Invasion with a Pirate Map. The enemies include no casters, and only one slow flyer. If summoned in the Ocean biome, the pirates themselves will drop several more Pirate Maps for later use.

Items

 * Golden furniture for display or sale.
 * Several money-related accessories as rare drops: Discount Card, Lucky Coin, Gold Ring.
 * The Coin Gun.
 * The Pirate Staff.

NPCs

 * Defeating the invasion once unlocks the Pirate NPC, who sells two placeable cannons and ammo, a pet, a costume, and a new decorative Wall.

The Frost Legion
If the player has played during the Christmas season, they may have obtained Presents. If opened during Hardmode, these can contain a Snow Globe. Snow Globes can be used at any time to summon the Frost Legion. The invasion itself is fairly easy, with no casters or flyers at all.

Items

 * The enemies create and drop Snow, making it renewable.
 * After defeating it, the Clothier will sell the Balla Hat and the Gangsta Hat.

NPCs

 * After defeating it, Santa Claus can spawn during the Christmas season.

Mechanical Bosses
When you feel you're ready, it's time to tackle the Mechanical Bosses. You may have gotten some of their summoning items already, if not you can easily make them. It doesn't necessarily matter what order you take them in, and the game-advancement effects kick in based on only whether you've beaten one of them, or all of them. However, each of them provides the Souls for particular weapons and tools. Once you've learned how to beat each of the Mechanical Bosses, it will be much easier to repeat the performance, in case you run low on Hallowed Bars or their respective Souls.

After One Mechanical Boss

 * Solar Eclipses begin to occur. These are almost twice as long as Blood Moons, with far tougher monsters. However, if properly harvested they can be hugely profitable, both in coins and dropped items.
 * On the, Reapers will immediately start to spawn during Solar Eclipses, and Broken Hero Swords will drop from Frankensteins and Swamp Things.
 * The Old One's Army goes to Tier 2, with six waves and Ogres at the end.
 * The Tavernkeep likewise sells Tier 2 sentries; hopefully, you've saved up enough Medals to buy one of those.
 * He also sells four sets of armor to buff each of the sentry types, all of which give bonuses to sentries and other minions.
 * Buy a Defender's Forge or two to increase your portable storage.
 * As before, your ultimate goal for the tier is to save up enough Medals that after you do defeat the Golem, you can buy a Tier 3 sentry up front. In the meantime, Ogre drops may be handy.
 * Red Devils and Lava Bats start to spawn in the Underworld.

NPCs

 * The Steampunker will arrive. She will sell the Clentaminator and its ammo, which can purify or create areas of Evil or Hallow much faster. Also she sells a Jetpack, not to mention Teleporters and the station to make Asphalt Blocks.
 * Several other NPCs will unlock more items for sale:
 * Greater Mana and Greater Healing Potions from the Merchant
 * More dyes from the Dye Trader;
 * The Tavernkeep sells Tier 2 sentries and armor. However, the price of an Eternia Crystal goes up to 1 gold;
 * Speed Hair Dye from the Stylist;
 * The Truffle will begin selling the Mushroom Spear and Hammush, and the Dark Blue Solution, which spreads the Glowing Mushroom biome;
 * The Pirate will sell the Bunny Cannon and Explosive Bunnies.

Items

 * Life Fruit will begin to grow in the Underground Jungle. Grab as much as you can and use it until you're maxed out. Once you are maxed out, sell them for easy gold.
 * You now have Hallowed Bars and one of the advanced Soul types. You likely don't have enough for full Hallowed armor yet, but especially with your new Souls you can probably make some new weapons: Depending on the Souls you have, the main targets include Excalibur, the Megashark or Light Discs (Destroyer), an Optic Staff or magical weapon (Twins), or a Flamethrower (Skeletron Prime).

The Second Mechanical Boss
Slaying the second of the mechanical bosses doesn't unlock anything special, but you get more Hallowed Bars and another soul type.

Hardmode Jungle
Slaying all three of the mechanical bosses opens a few more gates, primarily the ability to mine Chlorophyte Ore.


 * At this point, you hopefully have enough Hallowed Bars to make the armor. If you made too many weapons and/or got unlucky on drops, you might need an encore performance from one of them.
 * Solar Eclipses get Mothron and Reapers. Mothron will drop Broken Hero Swords, allowing you to progress to the Terra Blade, while the Reapers will drop their Death Sickle.
 * With all three of the advanced Souls, you can craft the Drax or Pickaxe Axe. This lets you finally start mining that Chlorophyte ore which has been growing in the Jungle.
 * The Chlorophyte weapons and tools include more than the usual options, and most of them have special abilities and/or projectiles.
 * Chlorophyte armor is a major jump in its own, and its upgrades have even more options:
 * The armor's Leaf Crystal is not controllable like a minion, but it hits much harder, and automatically shares its efforts between random targeting and your current opponents.
 * Over the next two bosses, its upgrades will comprise an intermediate armor tier with class-specific abilities: Turtle & Beetle armor for melee, Shroomite for ranged, and Spectre for magic. Each of these has its own optional pieces for even more flexible defense.
 * Turtle armor is quickly available for melee players, replacing the Leaf Crystal with damage reflection.
 * You can now upgrade your Poison Staff to a Venom Staff.
 * Having all three Souls unlocks additional, platform-dependent items:
 * You can upgrade any of the "class" Emblems to an Avenger Emblem.
 * Depending on platform details, you may be able to craft Biome Keys from Biome Key Molds, and/or Dragon armor.
 * Plantera's Bulbs start spawning, pointing the way to the next stage.

After Plantera
When Plantera has been defeated, a number of things happen, collectively entering the "late game":


 * The spread of Crimson, Corruption, and Hallow are slowed to 1/2 (50%) of their previous speed.
 * The Solar Eclipse gets new enemies: Butcher, Nailhead, Deadly Sphere, Psycho, and Dr. ManFly, each of which drops a powerful weapon.
 * New, nastier enemies will spawn in the Dungeon:
 * Each of them drops at least one powerful weapon and/or a key accessory.
 * Your Biome Keys will now open the four Biome Chests, yielding four powerful weapons (5 in desktop 1.4 versions), each of which comes one to a world.
 * Dungeon Spirits (from killing powerful enemies) will drop Ectoplasm. This new crafting material unlocks the Pumpkin and Frost Moon events, as well as Spectre Bars.
 * Plantera's death grants access to the Jungle Temple and the Golem boss, represented by the Temple Key it drops.

NPCs

 * The Cyborg becomes available. He sells Rockets and the Proximity Mine Launcher, along with nanites. The Cyborg is the last NPC to appear, with the occasional exception of Santa Claus.
 * The Truffle begins selling the Autohammer, used to craft Shroomite Bars.
 * The Traveling Merchant begins selling the Pulse Bow.
 * The Witch Doctor begins selling the Vial of Venom, allowing you to make flasks, arrows, and bullets inflicting the debuff.
 * If you get the Pygmy Staff from Plantera, the Witch Doctor will also sell several more summoner items: Tiki Armor, Pygmy Necklace, and Hercules Beetle.

Items

 * Spectre armor offers magic boosts, with an option for either damaging orbs or healing.
 * However, Spectre bars make no weapons and only a few tools: A Pickaxe, Hamaxe, and painting tools, all with extra range. Spectre Wings are overshadowed by the Hoverboard.
 * Shroomite armor is the strongest Ranged armor available at this point, and offers a stealth mode with bonuses.
 * Shroomite bars don't make weapons or most tools, except for the Shroomite Digging Claw, which is the fastest pickaxe in the game.
 * They do allow making the Hoverboard, with the second-best flight time plus hovering and speed.
 * Mothron can now drop The Eye of Cthulhu, the second-most-powerful yoyo in the game.

The Jungle Temple
The Jungle Temple provides yet another furniture set and the crafting station to make it, plus lots of deadly traps which you can take for your own use. It also leads up to the Golem fight. Defeating the Golem represents the beginning of the "late game":


 * The Golem itself can drop a variety of powerful weapons (no summon, though), and/or the key crafting materials for several upgrades: Beetle Shells for Beetle armor; a Sun Stone to complete your Celestial Shell; the Eye of The Golem for a Destroyer Emblem.  It can also drop the Picksaw that lets you mine Lihzahrd bricks and remodel the Temple itself.
 * Martian Probes begin spawning randomly, which can trigger the Martian Madness event.
 * The Old One's Army goes to Tier 3. The Tavernkeep sells Tier 3 sentries and advanced-tier armor. Eternia Crystals go up in price again.
 * The Steampunker sells the new "best wings so far", beaten only by the Fishron Wings and some of the Pillar wings.
 * Cultists spawn at the Dungeon's entrance, which can be used to summon the Lunatic Cultist and begin the Lunar Events.

After Golem
These challenges are all strictly optional, but offer great rewards for those that can manage to overcome them... or even those who survive long enough to get some decent drops.


 * Martian Madness provides the blocks for another furniture set, a new mount with a distance attack, a mount that can fly forever (as fast as the Dungeon Guardian), a unique hook, and an assortment of deadly weapons.
 * The Pumpkin Moon offers many powerful weapons, notably the Horseman's Blade, Stake Launcher, and Raven Staff. Also available are two pets, two high-tier wing tokens, and Spooky Wood.
 * The Frost Moon offers the chance of several powerful (but often eccentric) weapons, a pet, and a mount.
 * Duke Fishron, if defeated, will drop one of five powerful weapons, and his impressive Fishron Wings.
 * The Old One's Army reaches Tier 3: it will now have 7 Waves and Betsy, alongside with its loot, along with new sentries and armor. It's the most difficult event of the game.
 * If you have not acquired enough Defender Medals to buy a Tier 3 sentry, you may need to come back after the Moon Lord.


 * versions: These versions do not have the Moon Lord, instead they have  as the most powerful boss.
 * It drops Adamantite Ore, Spectral Arrows, and Soul of Blight.
 * Souls of Blight are used to craft Titan armor, Dragon armor, Spectral armor, Tizona, and the Tonbogiri.
 * However, these armors are (mostly) outclassed by the non-exclusive armors, and are very expensive to craft. The Tizona is similarly outclassed by the Terra Blade, in crafting and power, but the Tonbogiri has a very long reach and is more viable as a late-game weapon.

(endgame)
The Cultists at the Dungeon represent the start to a final marathon of boss fights.


 * Killing the Cultists at the Dungeon will summon the Lunatic Cultist, a difficult boss with a variety of attacks. When defeated, he drops the crafting station used for endgame gear.
 * Once he is defeated, the Celestial Towers will spawn, and they will not despawn until defeated, whether you leave the world or not. Some key notes:
 * Even a player who isn't powerful enough to defeat them outright can battle: Chip away at the spawns at the edge of the most convenient pillar until its shield breaks down, then make a run to kill the pillar. The drops from the first pillar should let them create at least one powerful weapon, which will help in defeating the next one.
 * Each fragment type can produce a few of its own weapons and other items. All four together can produce Super Healing Potions, the Lunar Hook and the Celestial Sigil.
 * Once all the Pillars are defeated, the Moon Lord will spawn, while the Lunar Cultists reappear at the Dungeon entrance. If the Moon Lord wins the fight, he will despawn, leaving the players to start over from the Cultists.

Defeating the Moon Lord will provide access to the final tier of equipment, with which you can establish ultimate power over your world.
 * He always drops one of several endgame weapons, representing three options for melee, and two each for rangers, magic-users, and summoners.
 * He always drops the Portal Gun.
 * Besides bullets and arrows, Luminite unlocks all four Celestial armor sets, plus their wings, pickaxes and hamaxes.
 * The tools are essentially identical except for appearance.
 * The Wings offer a choice between two sets of statistics: The Stardust and Solar maximize time and ascent speed, while the Nebula and Vortex instead offer hovering.
 * The armor sets support the class of their respective pillars, and are usually considered the best available armor for that class.
 * After many battles, combining Luminite with all the previous "advanced" bars (all in quantity), you can create the Drill Containment Unit.