Guide:Game progression

Terraria is a sandbox game, but that does not mean it is without structure or change. The game progression presents a lengthy cyclic pattern:
 * 1) The player explores a section of the world.
 * 2) The area provides new materials from the landscape, chests and pots containing new items, and new enemies which offer varied hazards, but also drop new items.
 * 3) The player uses these to upgrade their equipment, until they are ready for...
 * 4) ... a boss fight. Each new boss provides a uniquely challenging fight. Defeating the boss provides still more advanced equipment and materials. This may include new NPCs and new items sold by existing NPCs.
 * 5) The items gained from the boss will again improve the player's equipment, but the bosses' defeat will also present a new challenge, usually access to a new area, or the appearance of new enemies in a previously explored area. This returns the player to step 1.
 * 6) The most significant boss battles for progression are the Wall of Flesh and Plantera, which both change the behavior of the world itself (biome spreading and new enemies).

This page attempts to summarize the game progression, as delineated by bosses, NPCs, and suchlike, in text form. It will not give details about boss fights and such, see the particular boss's page or strategy guide for that. It will, however, 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. Other important pages relating to progression: NPCs, Hardmode, Bosses. Item-class pages such as Armor or Swords may also be helpful.

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.

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.
 * Collect all the Heart Crystals you find, but don't actually use them until you're ready (see "Tips" below).
 * Collect Critters as they pass. You can sell most of them for silver (or in some cases gold), but hang onto the worms (and anything with a better bait value) for now

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).
 * 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.
 * 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 50 silver coins for the Merchant. He will sell an assortment of basic items.
 * 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 Nest, but will be helpless when found. She and the Angler are the first of several NPCs who need to be found and "rescued" before they can move into your town. Her services are purely cosmetic, but some of the hair dyes can provide useful information, and she can buy your surplus items.
 * 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, you will promptly fall.
 * 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.
 * You can collect lenses to craft 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. Similarly, don't summon him when the sun sets: wait a few seconds to make sure he's not coming, and that it's not a Blood Moon.

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, but 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 begin to 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, a long-lasting food item.
 * Monsters will drop Goodie Bags. These mostly contain Vanity items 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.

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.
 * 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.

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. Make Clay pots or buy planters from the Dryad to grow herbs as you collect seeds. Start making potions.
 * Boots add mobility, and begin the crafting chain ending with Frostspark 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.


 * 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.
 * When you've got all the crate drops and plenty of metal, start stockpiling Crates, and continue until Hardmode. Note that biome crates can have unique 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.
 * 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.
 * Fishing 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 more-or-less reduced to resupplying potion ingredients.

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 (hereafter, "orbs"). After the first orb is broken, meteorites will begin falling on the world (always off-screen). There will also be a random chance each day of the Goblin Army invading.

Meteorites

 * 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, after the first orb is broken, 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 unmined crash sites.
 * 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 second orb broken will offer more drops, but otherwise ought to do nothing in particular.
 * Every third orb broken summons Eater of Worlds or Brain of Cthulhu.

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.
 * Goblin Tinkerer, after defeating the Goblin Army:
 * He sells the Tinkerer's Workshop to combine accessories.
 * He sells Rocket Boots, and a handful of other items.
 * He also provides a special service: By reforging an accessory, weapon, or tool, you can get 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 some summoner's armor up front, and a Tier 3 sentry 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 local boss 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.
 * 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 venture to the Caverns to get Jungle Spores.
 * Hornet Staff, Bee's Knees or Bee Keeper, and other Queen Bee drops.
 * Optionally 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 protection is a biggie -- the Umbrella is available before you've looted the sky islands (from surface chests or Wooden Crates). You may have found some Featherfall and/or Gravitation potions already; your first few Harpy feathers will let you craft at least the former for yourself. You will get several unique items from the Skyware chests -- while fishing can provide other jump bottles and a balloon, there's no substitute for a couple of items here. A floating lake will also let you fish for Sky chests 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 the last items needed to complete your Cell Phone, 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, the 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.

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.
 * Mechanic: She will be your main source for wires, switches, actuators, and other Mechanisms. You can also loot wire, pressure-plates, and a few trap items from the world.
 * Party Girl: Most of her wares are cosmetic and party-related, but some can be eccentrically useful.

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.

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
 * Fireblossom seeds
 * Shadow Chests may contain the normally late-Hardmode Drax. If you find one, keep it handy, as it will be very useful even in late Hardmode.

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. 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.
 * Reshape the landscape as you like -- if any ravines or mountains are annoying you, now's the time to do something about them.
 * Check your crates, you'll want to go into Hardmode with at least a stack or two. Two full stacks and at least some "Evil" crates will pay big dividends.
 * Stock up on potions, because you'll be wanting those more in Hardmode.
 * If you haven't already, make a surface Mushroom biome, and build a house there for Truffle to move in later.
 * 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".

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.


 * 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.

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.

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 particular challenge, but 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.

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, 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.
 * 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 sell the Gatligator.
 * The Skeleton Merchant can sell two new Yoyos, the Yoyo Glove 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.
 * 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.
 * Medusa Head: Will be very useful against Wyverns and the Destroyer. Given the hazards of hunting Medusa in the wild, the statue farm with lava is definitely the way to go. A Pocket Mirror would be nice, too.
 * 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. You might already have gotten a Giant Harpy Feather, which will produce a solid second-tier set of wings.  If you have some money you can buy a better set from from the Witch Doctor, or else you can wait a bit for one of the many other options.
 * Black Recluses: The Spider Nests 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 not, fish for Dungeon Crates until you get a Cobalt Shield from a Golden Lock Box.
 * 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 Tavernkeep armor instead.

Tips

 * If you have stockpiled crates, you can open them now for a head start on Hardmode ores.
 * Otherwise, smash altars that are found in the evil biomes in order to spawn Hardmode ores underground. Keep in mind that Wraiths will spawn when you break them, 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 most game-advancement effects kick in based on only how many of the three you've beaten. 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 accessories.
 * 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 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 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, an Optic Staff, or a Flamethrower.

The Second Mechanical Boss
Slaying the second of the mechanical bosses doesn't unlock much in particular.

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 the immediately available upgrade 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 happens:
 * The spread of Crimson, Corruption, and Hallow are slowed to 1/3 (33%) 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, 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 other items.
 * 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 optional 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 items.

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 with extra range.
 * The Autohammer, which crafts Shroomite Bars:
 * Shroomite doesn't make weapons or most tools, except for the Shroomite Digging Claw, which is the fastest pickaxe in the game.
 * Shroomite armor is the strongest Ranged armor available at this point, and offers a stealth mode with bonuses.
 * 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. It will also drop Beetle Shells, used to upgrade Turtle Armor into Beetle armor, and perhaps a Sun Stone to complete your Celestial Shell.
 * Martian Probes begin spawning randomly, which can trigger the Martian Madness event.
 * Killing Martians gives the blocks for another furniture set, plus a new mount with a distance attack.
 * The Martian saucer, on the other hand, can drop a mount that can fly forever (as fast as the Dungeon Guardian), a unique hook, and an assortment of deadly weapons.
 * 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 (the late game)
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.
 * 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.
 * is another late-game boss, the most powerful boss in versions.
 * 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.
 * In contrast, the armor sets support the class of their respective pillars, and are usually considered the best available armor for that class.
 * Combining Luminite with all the previous "advanced" bars, you can create the Drill Containment Unit.