Known Bugs And Glitches


 * Please list bugs with the Console Version at Known Bugs (Console) and bugs with the Mobile Version at Known Bugs (Mobile).

This is a list of  currently in-game. If you find a bug, please list it below to allow others to see.


 * N.B.: Just because a bug can be exploited doesn't mean it should be exploited. You need to play the game the way it is most fun for you. Duplicating items may make things easier, but it is wise to remember that much of the fun comes from the challenge in the first place.

General

 * If the player is on a wall using the Tiger Climbing Gear and heals via the nurse with full health they will still be charged.
 * There is sometimes a problem with an inability to make use of any Crafting stations.
 * There is a bug caused by the player automatically climbing short hills which causes the player to sometimes go through blocks (see this image).
 * When a player has 2000 (20 stacks) Platinum Coins in a storage item or their inventory, the storage will glitch and only show three slots of storage space. If the player opens another storage item, then the "quick stack", "loot all", and "deposit all" buttons will disappear. Saving and quitting will cause the 20 stacks of coins to disappear.
 * Placing a Music Box on two Wood Platforms then erasing the platforms will cause the Music Box to float.
 * Rarely, placing a Torch on corrupted blocks simply causes it to vanish inexplicably.
 * The item value has no space between for example Gold and Silver coins.
 * Hermes Boots, Spectre Boots, and the like can allow the player to fall through gaps in the floor one square wide, if they run into a wall just above it fast enough.
 * Placing two Doors adjacent to one another and repeatedly opening and shutting them may lead to one of the two doors glitching, which results in spawning an infinite number of duplicate doors whenever the adjacent door opens or closes.
 * Though extremely tedious, it is possible to exploit this glitch to earn significant amounts of gold, as each stack of 99 doors is worth nearly 40 silver.
 * Fall damage is inconsistent when landing on anything 1 block (sometimes more) thick.
 * It is possible to use the Grappling Hook or its variants to go through spaces which are normally too tight to fit through.
 * If a Giant Worm attacks the player while they are near a one-block wide tower of sand, they may be knocked through the tower.
 * Occasionally, clicking the GUI opened for a Sign can cause the game to crash and pull up a .NET error message.
 * Chests will float if the sand they were place on is removed, though not from directly under it. The sand must fall by removing the tiles below it.
 * It is possible for the player to walk through a closed door:
 * Close the door, and move as close as possible to the door.
 * Open it, tap the 'move right' key once very quickly, close the door, and move farther into the door.
 * You should not notice even a pixel's worth of movement if you do this correctly.
 * This can also be achieved if using the active/inactive stone blocks or Actuators, and a switch. Stand in the blocks whilst they're inactive, and then flick the switch.
 * Sometimes, " " will appear instead of a regular Death Message.
 * This appears to be replicated most easily by attempting to smash a Demon Altar prior to defeating the Wall of Flesh.
 * When there is a Chest surrounded by thorns, breaking the chest before the thorns around it may make several extra chests appear upon destroying the thorns themselves.
 * If you place a bottle on a wood platform and place a torch next to it, the torch will break and some torch particles will appear.
 * As of 1.1, all four edges of the world were moved closer to the spawn point by at least 12 blocks, making anything built along those edges irretrievable.
 * If the player's bed was in that area, they will spawn on the nearest block to their lost bed on the new edge of the world.
 * Sometimes in multiplayer, when a world is updated to 1.1, 12 blocks on each corner will be removed, but the size of the world will remain the same, making a 12 block wide/high space that contains nothing that the player can access. The map generator was not updated to handle this, and Gold Chests at the edge of the world in the Oceans will not be visible.
 * This bug can easily be solved using F9 to cycle through your light engines, two of which cause this 'shrinking' of the map.
 * If the player dies while fighting the Frost Legion on Mediumcore, they will drop coins like with any other mobs. However, if platinum coins are dropped, then they may not show back up in the player's inventory, or the name may show up in the slot but no coin is actually visible and NPCs will not acknowledge them.
 * If the player attempts to launch a grappling device at the exact center of their character, then the game may crash.
 * Looting items used in crafting from a chest can occasionally glitch the crafting menu, allowing anything associated with the looted materials to be crafted.
 * When entering a world, the player can sometimes die from fall damage even though they didn't fall, regardless of fall damage cancelling items.
 * On rare occasions, when a player attempts to close a door, it will instead be destroyed and rendered unable to be picked up.
 * If a character receive too many buffs, the game will say "buff overflow" and the character in question can get deleted.
 * Sometimes, dropping magical weapons (weapons that use mana) will recover 20 HP to the player if they do not have full health.
 * When a player has multiple keys (that unlock Locked Chests) and attempts to open a locked chest, instead of consuming one key, all keys may be consumed.
 * Having a closed door at the original spawn point of a world may cause players spawning in to obtain two doors when the door is broken.
 * Sometimes an endless night without a moon may occur.
 * This can be fixed by exiting and re-entering the world.
 * Sometimes, in Hard Mode, a message appears stating that the world has been blessed with one of the three ores (Cobalt, Mythril, Adamantite, or their alternate versions) even though no Demon Altar has been destroyed.
 * Attempting to place a Campfire into Honey causes a duplication glitch.
 * Using an Ice Rod to place ice, putting a chest on top, putting an item in the chest, and then exiting and re-entering the world will cause the chest to be floating in midair. Attempting to place blocks around the floating chest will cause it to duplicate.
 * On some computers, adjusting the music is impossible. Clicking the - on the music won't do anything, clicking the + will increase the sound. Also, clicking - or + on the sound will both decrease the sound.
 * On some computers that use small monitors, the EXIT button is unavailable due to the size of the window. The only way to get around this is to switch to fullscreen.
 * If a player falls while they are lagging, light and shadows will not load properly.
 * Heart Crystals can occasionally be found balanced on one block rather than two. In cases like this, placing a chest under the crystal and then removing it again will leave a corner of the chest behind. Attempting to place a chest there will now spawn duplicated chests.
 * Very rarely, if only half of a demon altar has spawned, it can be destroyed with a hammer other than the Pwnhammer.

Singleplayer

 * If the player opens their inventory and clicks an item during their character's attack animation, the item in question will be unable to be put down and will be dropped when the inventory is exited. (Note that this will only happen when autopause is on.)
 * Creating a world can sometimes crash the game and partially or completely corrupt the character file.
 * It is possible to drink an unlimited number of Potions without activating the Potion Sickness debuff (Note: this glitch requires Autopause to be enabled.):
 * Swing any weapon or tool and pause the game right in the middle of the swing (fairly easy to do if the weapon has a high use time).
 * Select the healing item by left-clicking or right-clicking the item of your choice.
 * Unpause the game and your character will interrupt the swing and instead consume the healing item.
 * There is a possibility where you might "eat" items this way where certain items are consumed when you pause the game and accidentally select an item with a different intention while swinging.
 * It is impossible to place tables and other Furniture above a certain height.
 * If the player and an NPC open a door at the same time, the door disappears.
 * With frame skip off and in windowed mode, clicking the Terraria taskbar icon to minimize the window will cause the game to drastically speed up.
 * Chests' contents sometimes disappear.
 * Opening a door while wiring over the door opens it simultaneously, the door will disappear.
 * When an Npc tries to open a door when there is a painting on the other side, the door and the painting will drop and the door will turn into a flesh door.

Multiplayer

 * Upon joining a multiplayer server, the menu music may still play while the in-game music is playing. It may or may not be related to the issue where day and night music play at the same time. (Day, night, and title could also all be heard at once.)
 * Occasionally, placing more than one gold key in a chest duplicates it, turning it into a stack of 99 gold keys.
 * If the server is laggy enough, falling a large distance (e.g., a Hellevator) may allow players to fall into areas where the map has not yet loaded. It is possible to hit the end of the world without touching any blocks in this way.
 * If a guest to a server places armor on a Mannequin, it will not be removed from their inventory, and will be duplicated on the mannequin. This allows for the infinite duplication of any armor already possessed.
 * Occasionally, when leaving and then proceeding to join the server, you may get a message saying that your character is already on the server, and you cannot join.
 * This can be fixed by the host of the server kicking your character from the server. You will then be allowed to rejoin.
 * Sometimes, your game will crash repeatedly when you try to connect to a server.
 * Sometimes, holes will inexplicably appear that lead to the bottom of the world. Since this does not happen in singleplayer, it is assumed to be a server-side bug.
 * You can avoid it by placing your base near the left edge of the map from the start, as the "holes" always seem to be on the same spots every time (Example)
 * If you minimize the server window, time speeds up (when clicking the server window button in the task bar; might only happen on Windows 7/Vista.). It looks like the sun and moon "teleport" forward. In addition, the Monsters are super fast. Maximizing the server window fixes this.
 * Game may crash if you save your spawn point in a Bed and reconnect - the server must be reopened.
 * If the players fail to kill Skeletron, the Old Man may not respawn. The players will still get attacked by skulls in the dungeon itself. This bug seems to occur if a spawn location is set within sight of the Skeletron.
 * If players set a spawn point that is at the "end of the world" (past the beach and over the water) and disconnect from the server, they will be unable to reconnect. The reason for this is unknown, and the problem is fixable if the affected players connect to the world in single player and reset their spawn point.
 * Setting a spawn point at a high elevation (i.e. on a floating island) may cause a player to be unable to reconnect.
 * If you start to play on a server for a while you might get kicked and it will say "explosions are disabled on this server" and this will happen for about 10-15 minutes. It is thought to happen when players destroy many blocks within a small time frame on a lagging server and the server recognizes it as an explosion.
 * Eater of Worlds may spawn away from where the third shadow orb was broken, near another player in Multiplayer.
 * Gold Chests may not appear gold to all players. Some Gold Chests may also appear to be part gold to some players. This is fixed on reconnect.
 * Planted flowers may not appear the same to all players (i.e. Daybloom may look like Blinkroot and vice versa).
 * Shadow Orbs may not appear to be whole (i.e. a quarter shadow orb), but still act like a whole shadow orb (i.e. the quarter shadow orb summoning the Eater of Worlds)
 * Doors will randomly disappear in larger houses.
 * Very rarely, a message will appear saying you died even though you didn't, allowing the game to believe that you are "dead" and haven't respawned yet. This allows you to run around without any enemies spawning near you (be careful though, they will spawn near other players). (confirmed; happens on slightly laggy servers while surviving "On Fire!" Debuff with extremely low HP)
 * Continuously firing the Megashark will get you kicked by the anti-cheat mechanism.
 * Players may fall through a one-block hole.
 * Sometimes summoning a boss (tested on Eye of Cthulu) will use up the summoning item, but the boss won't spawn.
 * You can't stack 100 Gold Coins to make a Platinum Coin. If you try, you won't get any Platinum Coin and your Gold Coins will be gone.
 * If all characters are stacking their money into one source (i.e. a chest or a Piggy Bank) using the quick stack option, a player's money may occasionally fail to transfer, causing it to disappear.
 * When two players spam opening and closing a door, the door may break and not drop the door item. This may also happen with items such as Levers.
 * There is a bug that occasionally a player (that is not the host) can lose ALL items with no explainable reason. There is no known fix.
 * There is a bug where if there is a player in an emptied object and it is broken, the game will either crash or black out. (Unconfirmed)
 * Firing the Flare Gun at another player with PVP enabled will cause the player to gain the "On Fire!" debuff on the screen of the player who fired said Flare Gun. Placing the cursor over the burning player will show their health decreasing over time, but it will reset to the proper value every few seconds until the fire goes out.

General Behaviour

 * NPCs sometimes keep their housing sign up while it is not suitable. Upon reloading the world, the sign will vanish.
 * NPCs sometimes have pathing issues when attempting to reach their rooms, particularly obstacles over 3 squares high, which they can't jump past. If you reload the world though, they should spawn in their assigned housing.
 * NPCs have pathing issues regarding Wood Platforms.
 * When you spawn for the first time, the Guide can spawn twice for an unknown reason. (Needs Confirmation)
 * Sometimes an NPC will spawn Underground and won't be able to climb up.
 * When your mouse moves over Santa's banner in housing mode, it says Santa Claus the Santa Claus, instead of using the NPC's name. (Not really a glitch; the game mechanic dictates that all NPCs have a name and a type, although Santa Claus' name is his type)
 * If you follow an NPC as they go to open closed doors, you are able to walk through. If you follow them just as they are about to close it, the door may disappear.
 * Some NPCs (namely the Clothier, Old Man, the Goblin Tinkerer and the Mechanic) will walk over cliffs they can't climb back up instead of turning around.
 * If you have autopause on when you talk to the Mechanic, Goblin Tinker, or Wizard while they are bound underground, they will stay bound, even though they say they are unbound.

Dialogue and Purchases

 * When purchasing items from an NPC brings you down a coin tier (1 gold coin to 99 silver, etc.) there is a chance the game will register the higher coin as still being there, though the sprite will not show and it cannot be spent.
 * This can be fixed by mousing over each coin space in your inventory until you find the invisible coin (the item name and amount will show) and left clicking it.
 * Until it is fixed, the game will attempt to stack all additional money with the nonexistent coin, resulting in lack of funds.
 * If you have autopause on and are close to an NPC, you will be able to talk to them as if the game was still playing, while everything around you will remain still. This can be useful if you are fighting a boss and have low health and the Nurse is near. (Singleplayer only)
 * Sometimes your Dryad will tell you that your world is 0% corrupt and will not tell you how much hallow there is; probably caused by the 1.1.1 update. New items that appeared after the Wall of Flesh were not purchasable, such as the Hallowed Seeds.
 * When a Nurse and yourself are in range of a Campfire, if you speak to her when at full health you will still be able to pay to Heal yourself, though her quote will be something like 'I've Seen Bigger Wounds'.
 * Fixed by simply moving the campfire away/making the nurse is out of range of the campfire.
 * Closing a dialogue with the Nurse while having the Mechanical Eye, Worm or Skull equipped causes "The Twins", "The Destroyer" or "Skeletron Prime" (respectively) to appear without consuming the item. (May also occur for other boss summoning items, needs confirmation)
 * If you talk to your Arms Dealer in a world where Skeletron has been defeated and the Wall of Flesh hasn't while your guide is dead, the arms dealer will say the name of the next guide.

Spawning

 * A one block high space allows Slimes to spawn, but also allows them to jump through the floor as most slimes are two blocks high.
 * If you stand near one of the edges of a map (left, right, top, or bottom), you can see monsters spawn on screen. This is because the monster spawning algorithm considers "offscreen" to be a certain distance from the player, rather than what the camera can actually see.
 * Rarely, Skeletron will be summoned randomly, kill all players near it then despawn.(But where and near what?)
 * The Dungeon Guardian can spawn where you respawn after it kills you.
 * Sometimes when you break a Shadow Orb, it doesn't say "A horrible chill goes down your spine..." Instead it will spawn the Eater of Worlds without the message "Eater of Worlds has awoken!"
 * Very rarely, Harpies or Wyverns may spawn around ground level. This happens when the altitude of the ground is high enough.
 * Chaos Elementals can appear in the Underground Hallow even if Hard Mode is not active, causing much hassle to pre-hardmode characters.
 * If the spawn conditions for the Eye of Cthulhu are fulfilled, and the Eye of Cthulhu has not been defeated in the world yet, using the Suspicious Looking Eye after receiving the "You feel an evil presence watching you..." message but before the Eye spawns can result in having to battle two Eyes of Cthulhu simultaneously.
 * Sometimes if you hit a monster a pink falling star will go past your screen.

Behavioral Glitches

 * When the Wyvern is killed in multiplayer and the server is lagging, the head may still attack you even though it's already dead.
 * Demon Eyes can sometimes travel through a 1 block thick layer.
 * Slimes, if trapped inside a 1 unit space, can travel through walls whenever it tries to jump, which allows it to follow you anywhere around the world unless it "despawns".
 * They can also sometimes jump through 1 unit holes, but this seems to not work when the blocks are made of certain materials, like Stone.
 * Some monsters drop more than one Silver Coin, but sometimes when collected it only counts as 1 Silver Coin.
 * The Destroyer might disappear after about 90% of its health is gone.
 * When you have locked in a Demon in the 'Hell' world, with dirt 4x4 blocks, it is possible for it to go through the layer of blocks that is under it. (Unconfirmed if it works with other kinds of blocks or other monsters)
 * Sometimes when a Demon Eye is trapped between 1 layer of blocks above it and a thick layer of blocks below it (that leads to the underground), it may sink down to the thick layer and fade away. (Dirt confirmed)
 * Sometimes the Wall of Flesh will drag you up to the surface and push you past the world boundaries if you survive (band of regeneration required), and crash the game.

Map Generation

 * Jungle Shrines can be generated in lava pools with no chest inside them.
 * Jungle Shrines can be generated in the sky (~15 blocks above the ground)
 * In some map instances, it may be impossible to find certain unique items. (Intentional)
 * Chasms can also spawn where Dungeons should be, and sometimes block the way in. In this case, you'll need a Nightmare Pickaxe (or above) or Purification Powder to dig through it, opening the way to the Dungeon.
 * Corruption can sometimes be generated within 100 blocks of the main spawn upon initial map creation, without Sunflowers blocking them. These Corruptions can spread and cover the spawn.
 * Digging straight down from the spawn point generally leads you to a Glowing Mushroom biome. However, not always directly into the biome, but always within a screen of the biome.
 * Fairly often, you will also happen across one or two Demon Altars quite close to each other around sea level fairly close by the spawn point.
 * The Underground Jungle sometimes will fuse with the Underground Corruption, causing several/all Shadow Orbs to despawn before the map is even generated fully.
 * Dungeons can sometimes be created in a lake upon initial map creation, submerging the Dungeon entrance. Anything beyond the door of the Dungeon will not be submerged, however.
 * Its extremely rare to find the underground corruption generated under the ocean while the corruption combined with the jungle.(PS3 comfirmed, unknown for PC and xbox360)

Weapons

 * The effect of Molten Armor applies sporadically to damage from the Ball o' Hurt and Harpoon. (Not yet confirmed with other flails)
 * If the player's inventory is full (not including ammo slots) and each of the ammo slots has at least one item in it, there is a bug where ammunition can only be picked up by temporarily displacing one of your items. The type of ammunition makes no difference, nor does what item you move momentarily. (Intentional/insurmountable programming paradox; the ammo must hit your inventory before it will go to the ammo slots)
 * The Dao of Pow can fall through blocks if held in one area and fly under the player if there are blocks under and if the player goes up such as flies up or grapples onto another block, the flail will come out of the ground towards the player even if the player has not gone far enough to make the flail come back to the player forcibly. (??? - Needs serious clarification)
 * If a player is on the bottom of the world and controls a projectile made by the rainbow rod, then guides it upward to a certain location, the rainbow rod projectile will become invisible but will still be there and if the player moves it out of the certain location downwards the projectile will become visible again.
 * When using a Grappling Hook, if the mouse is aimed at a Wooden Platform above the player and the E key is pressed, then the icon for the Grappling hook in the Hotkeys will disappear when the player grapples to the platform. One must open and close the inventory screen once to fix this.
 * When the player is next to a 1 block thick wall, or a door, and throws a boomerang at it, if the player throws the boomerang in the right direction it will go through the wall or door.
 * On the Xbox version of Terraria, the Vilethorn doesn't shoot a projectile, yet instead the projectile stays in place for a while, but still hurts enemies like normal.
 * If a Dao of Pow reforged to a certain modifier enters water, it will drop down a layer under the water. (Unconfirmed; modifier unknown)

Water
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 * It is possible for a small puddle of water to turn into a never-ending waterfall when the bottom is dug out.
 * An infinite pool of water can be made with a "J" dug into the ground by placing water in the center, taking it out of the shallower side, and repeating.
 * Pumps toggled fast enough will duplicate whatever liquid you have them moving.
 * As of 1.1, water stuck in blocks will disappear if the server is empty or if the game is shut down.
 * As of 1.1, if a player flies into a block with water stuck in it, the player's breath meter will pop and the player could die if they stood still flying on the block while their health goes down after their breath is gone.
 * If a player tries to grapple on a block with water stuck inside it, preferably glass, the hook will detach from the block before the player can get to it. This can also happen on side blocks and propels the player towards the blocks.
 * When you dig any block under water the water will duplicate causing it to be able to flood hell/underworld because the new water does not apply the water fading in the underworld.

Crashing

 * The game crashes upon exit from the title screen on some games.
 * If the game crashes unexpectedly, is then restarted and the same world reloaded, sometimes all blocks are removed and the player falls directly to the bottom of the map causing them to die. All world data appears gone and is irretrievable although map files still exist.
 * In this case, you can either use Cloud in a Bottle or Rocket Boots to survive the fall at the bottom when the screen no longer centers on your character.
 * Hellbats will spawn out of the bottom of the screen and pools of lava can be found in Hellstone, along with Hellforges.
 * Further exploration has shown that not all blocks in the rest of the world have disappeared, though most have. There will be large amounts of dirt and stone with minerals spread throughout it, but suddenly cuts off at the point where the rest of the world seems to have disappeared.
 * Putting a laptop to sleep by closing it while in-game can sometimes cause it to crash when you save and quit.
 * Sometimes, when attempting to save and/or exit the game, Windows will notify you that Terraria has encountered an error and needs to close, and thus you will lose any unsaved changes.
 * The cause is suspected to involve the player character, as you can fix the bug by logging in with a different character, saving, and then switching back to the character you were previously using. People who often use multiple characters likely won't encounter this bug.
 * The above bug may also be caused by duplicate world files for the same world slot, and cannot be fixed, only affecting one world.
 * In which case you should go to your computer's start menu and search the file (formatted as world1 or world2 etc.) and delete the .sav file of the affected worlds, this may delete the world if you select the wrong duplicate (recommended to back up computer before this) but will un-glitch all further instances of this bug.
 * If on server, selecting an item sometimes makes the game crash.
 * Sometimes when right-clicking items in a chest or in the inventory, the game crashes. This is often caused by audio devices being disabled, or out of date BIOS or sound drivers.
 * Sometimes editing signs will cause the game to crash.
 * Sometimes placing armor in an armor slot will cause the game to crash if the player is using a non-English language. This is due to missing language files.
 * Using the rod of discord and teleporting to the right end of a large map will crash the game.

Visual

 * Falling Snowflakes 'phase' through walls and the ground and don't appear to obey the same rules as raindrops (which stop when they hit a surface and won't go through solid walls or ground) - snowflakes even appear underground - seems that snowflakes are being drawn in the foreground when they should be drawn the same way as raindrops.
 * Alt-tabbing in and out rapidly can cause unusual colors. Alt-tabbing again fixes.
 * When playing a world for the first time there is a chance no HUD/GUI is displayed. (Can be fixed by pressing F11)
 * Moving to fullscreen causes all things to speed up i.e. the sun and moon move at an increased pace. It is suspected that this is because your monitor's refresh rate overwrites the game's when running it in fullscreen.
 * When running the game in windowed mode, clicking on another window that doesn't cover the Terraria window will cause any light from Mining Helmets and armor sets with lighting effects to vanish (does not occur in multiplayer). Clicking back into the window allows it to light correctly. This does not affect the game, as it pauses when another window is clicked.
 * The lighting effect of a Meteor crash site may remain even when all meteor blocks have been mined.
 * When Hellstone and lava stop glowing, (in The Underworld) the Rocket Boots' fire particles, the Flamelash's trail, and the Molten Armor's glow particles are no longer visible.
 * For unknown reasons, attack font can sometimes be distorted and glitch into unrecognizable numbers. (Example) This bug does not affect critical attack numbers, and can be fixed by simply leaving and re-entering the affected world.
 * When using Dynamite on Ebonstone it will explode and leave a gap for a moment, but then it looks like there was no explosion. The blocks that reappear will be solid and the ones that exploded will be trapped inside the blocks that reappeared. (May happen with other blocks; unconfirmed)
 * Sometimes, when changing to fullscreen and then switching back to normal, only half the game is visible.
 * When the game is loading tiles after just having connected to a server, alt-tabbing, or using a Magic Mirror, may cause many blocks new to the 1.2 update to be invisible for anywhere upwards of a few seconds.
 * Since update 1.2, Wood Platforms can be moved up and down when struck with a Hammer. However, this does not change the actual position of the platform.
 * For instance, placing any item over the platform, like a Clay Pot, Pink Vase or any other placeable item will place them over the original location of the platform, even if it was moved down, causing it to "float" in the air.
 * Sometimes the background ("Wall") when underground (rocky and mud-rocky) will start to follow you and glitch, jerking about in random motions. (This is because the 'rocky' walls are actually part of the skybox, and aren't actually back walls. Parallax affects the skybox. It's not a glitch.)


 * Turning parallax down to 0 makes it stop.
 * If you stand on the lower edge of a sloped block which is on top of a half block,  you will appear to float.

Audio

 * Two themes can play at the same time if the change happens on the instant of the current song being re-looped. This will last until the theme playing before the change of day/night, location, or etc. starts a new loop.

Item Cloning
These bugs cause you to be able to clone items. Keep in mind that cloning means duplicating. You cannot obtain items you did not already have at least one of via cloning methods.

Running two instances of Terraria
To clone items in Terraria single player; open 2 copies of Terraria, and in both copies, sign in with the same character. In COPY A, open WORLD A, and in COPY B, open WORLD B. In WORLD A, put ITEM X in a chest. Save and exit to the title screen and exit the game client. Open COPY B and save and exit the world. Do not close COPY B. Enter WORLD A and go into the chest you put ITEM X in. ITEM X will be in the chest and also in your inventory. {C}This method works because when you save and exit WORLD A, ITEM X is saved inside the chest. However, because you have 2 inventories opened, ITEM X will stay in your inventory in WORLD B. So, when you go into WORLD A again, you will still have ITEM X in your inventory. (Sorry about all the As and Bs)

Note: A Steam update has made running 2 instances of the same game impossible. However, you can still run 2 instances by opening any folder, and in the address bar typing "%HOMEDRIVE%\Program Files\Steam\steamapps\common\Terraria" and selecting "Terraria" or "Terraria.exe" depending on your settings. You should not have both of these(or one of them wont have an icon, and you can not run it), so deciding which should not be a problem.

Tips to copying character files and world files
If you decide to clone items by copy/paste world or character files, be sure to know which file is which: player1.plr appears below player1 - Copy.plr, which also appears below any subsequent copies (of which copy 2 comes at the top, and then 3, etc.) of the player file. To be sure which copy you are using (or the original), please know that the order of the characters found in the Terraria character selection screen mirrors the order found the the "Players" folder. The same is for world files.

Closing a server or disconnecting abruptly
Item cloning can also be performed by placing an item in a container on any server, saving the server, then starting it again. Once the player revisits the container, if they take the item, disconnect, then close the server improperly (such as alt + F4 on the server tab) without letting it save, the item can be found yet again in the container. For example: A Video Showing this method can be found here
 * 1) Player A leaves ITEM X in a chest.
 * 2) Player A disconnects.
 * 3) Server is disconnected/saved.
 * 4) Server is reconnected.
 * 5) Player A connects and takes item.
 * 6) Player A disconnects.
 * 7) Server is closed abruptly without saving the map.
 * 8) Server is reconnected.
 * 9) Player A joins.
 * 10) Player A takes ITEM X and now has a duplicate.

Another example:
 * 1) Player A drops an item in a server.
 * 2) Player A disconnects abruptly.
 * 3) Player A rejoins server.
 * 4) Item is still in Player A's inventory as well as in the server.

If you have played for a long time in your current session, make sure you disconnect and then reconnect to the server before you start duplicating items, or you will lose items you obtained recently. (Because the server did not have a chance to save them.)

Mass produce items from chests, involving two players
You can create and mass-produce items in multiplayer from chests, to do this you require some teamwork with another player, player A puts 1 gold ore in a chest slot, player B checks the chest, player A removes the gold ore, player B can now right click the spot were the gold originally was and obtain a gold ore, he can then proceed to right click empty chest slots to increase the number of ores he has, however, these ores are nameless and can-not be used in crafting, but they can be placed on the ground then mined, now with a name and now craftable, since this can be done with any ore, all endgame items can easily be obtained after the players obtain at least one Adamantite Ore. It should also be noted that players are able to sell the nameless items for the same worth of the item being duplicated, letting players duplicate endless diamonds for consistent coins, dropping any nameless items results in the item being randomly made into something else with exactly the same number in the stack but is still nameless. (As of 1.1, two players cannot be looking in the same chest. This glitch is no longer possible.)

Duplicating entire worlds
The second easiest way to clone items is to simply clone the item world file. This can be done by opening the Start Menu, going to Documents, going to My Games, then clicking the Terraria folder, then the World folder, then copying the world file, pasting it in the World folder you are already looking at, and then renaming it as another world. This can only be done if you have less than 5 worlds. For example if you only have 1 world the World folder will say, "world1.wld" and "world1.wld.bak". You can copy world1.wld and paste it again and it will be named "world1 - Copy.wld". Rename this as "world2.wld" and then exit the folder and start Terraria. The game will assume this is just your second world file but it will really be an exact copy of your first world.

Duplicating characters
A method is to go into the player file and copy the character. For example you have player3.plr and player1.plr, copy player3.plr into the players folder, then rename the copy to player2.plr. This will result in a clone of the player which has the same items as the player that was cloned. This is a very efficient way of farming anything.

Doors in lava
There is also a way to duplicate doors by placing a thin layer of lava on the ground that does not hurt you and placing a door in a doorway. Once you have placed the door, right click it continuously, do this and you will have stacks of doors, if you aquire them. This means that you will get infinite doors for any use.

Infinite Chests
By placing chests (must have something in them) on top of active blocks an triggering the blocks, chests will spawn at a ridiculous rate. This can very quickly fill your inventory (less than 12 seconds). If gold or shadow chests are used, this can generate huge amounts of money quickly, as a full stack of 99 gold/shadow chests sell for. (This no longer works as of v1.2)

Infinite Clay Pots
In 1.2, if you try to place a Clay Pot on a reshaped block (e.g. a lowered block or a slope), the pot will clone infinetly, quickly filling up you inventory. It works on any solid block and doesn't work on Wood Platforms. This is quite an easy way of farming money in the early game, as every stack of 99 pots is worth, and you get a full stack in around 5 seconds.

Infinite reforged items
There is a way to clone any item that can be reforged. By talking to the Goblin Tinkerer and selecting "reforge", place the item you would like to clone in the box, now you can choose to reforge or just click "Save and Exit" when you Save and Exit simply reload your last character and world and the item that you placed in the box will drop in front of your character. (No longer works as of PC v1.1.2)

Infinite Music Boxes
If you place a recorded Music Box on a Table or Workbench, it will multiply and each can be sold for. (This no longer works as of v1.2)

Getting 2 Cooked Marshmellows with one Marshmellow on a Stick
In version 1.2, cooking a marshmellow by holding it on the cursor rather than from the hotbar will result in gaining 2 cooked marshmellows; one in your inventory, and one in your cursor. If somehow your inventory gets full while doing this, however, you will get only one of the item.

Bar Duplication
''This Bug only works on Multiplayer. It has been tested and does not work on singleplayer.''

In version 1.2.0.3.1, If you stack Bars (All types) about 10 high, with several stacks right next to eachother, and you destroy the bottom bars with a very fast pickaxe (like a drax) the bars can duplicate. Sometimes this may not work, and rarely, you can lose some bars.

Fixed Bugs
These notable bugs have been fixed and no longer exist in the current version of Terraria.

General
NPCs:
 * After knocking down a large tree, pieces of wood get stuck underground and stay there until you dig them out.
 * Place a door under water and constantly open and close it. The water will slowly disappear up to the base of the door. This is probably caused by the water in the 3 blocks that the door occupies being destroyed when the door is closed. (Water can now occupy the same space as a closed door, showing the door behind the water.)
 * Dirt no longer mixes with sand when controlled with the Dirt Rod, Instead, the dirt breaks, and can be picked up.
 * In mediumcore, when you die, if an item is in the trash bin spot, it will stay with you when you die.
 * If you kill yourself and, right before you die, take your money out of your inventory by left clicking it, half of your money will still drop where you died, but you will still have your original stack. Basically multiplying your money by 1.5. making it possible to get unlimited money.
 * Oceans may spawn where Dungeons should be, causing the entrance to the dungeon to only sometimes be visible/accessible.
 * When you place a music box on a table or workbench, it will duplicate itself and create many copies (you can sell these for easy platinum coins).
 * NPCs may fail to spawn, even though there are valid houses in the world and conditions are met.

Monsters

 * Creating an artificial Jungle: even if the depth meter says you're below sea level, hornets or man eaters will fail to spawn.
 * In the Underworld, Piranhas will spawn in lava causing them to die the instant they spawn.

Weapons

 * In mediumcore if a weapon with modifiers is dropped upon death the weapon will lose it's modifiers. (This has been fixed in the 1.1.1 update)

Multiplayer

 * A problem in the Client-Server synchronization causing monsters to suddenly teleport to another location when they are dealt damage by the player. (If this still happens, it's because of a bad host.)
 * The game may crash when you break 4 Shadow Orbs in a row.