Known Bugs And Glitches

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

Keep in mind though, just because a bug can be exploited doesn't mean you should. Duplicating items may seem like a good thing to do at first, but it can rapidly make the game a lot less fun to play.

''NOTE: This is a clustering of various separate bug and glitch pages. It needs cosmetic and redundancy work done on it.''

General

 * Sometimes when you load a save file, your NPC's in that save file will be lost and you cannot open your chests. However you can break the chest with a Hammer but if you place it again, the items placed in the chest are lost.
 * During a Blood Moon, zombies level with a wood wall can inexplicably turn that wall into a door, then proceed to open it, and enter your home.
 * The Hermes Boots can let you fall through gaps in the floor one square wide if you run into a wall just above it fast enough.
 * Blowing up a chest with dynamite causes the chest to duplicate 10+ times. Also, forming obsidian over the top half of the chest leaves you with the bottom half of the chest that can be "removed" infinitely, allowing for infinite free chests.
 * Upon forcing the game to quit, (ie Windows Task Manager), the game saves the items in one's inventory, but any blocks placed or changes to the terrain will revert to the last time the game was saved correctly.
 * Placing a torch onto a piece of wild grass next to a door causes the torch to duplicate. This bug can be exploited to have a lot of torches without getting a lot of slime gel.
 * 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.
 * Grappling onto the middle of a door (just above the doorknob) and opening the door will fling you forward at the grappling hook's pulling speed
 * Fall damage is inconsistent when landing on anything 1 block (somtimes more) thick.
 * You cannot make a spawn point with Dungeon Bricks and/or Walls. This may or may not have to do with the fact that one could otherwise place beds in dungeons themselves, and easily loot chests and other things before killing the Skeletron by spawning at the bed every time they are killed by the Skeleton Heads.
 * Removing sand from underneath an altar causes the altar to disappear, although it is relatively rare to find altar on sands.
 * After knocking down a large tree, pieces of wood get stuck underground and stay there untill you dig them out.
 * The game can speed up for no reason, in both single player and multiplayer; this mainly seems to happen when game is first loaded up. This glitch may have been fixed for multiplayer in the 1.0.3 update.
 * It is possible to use the grappling hook or its variants to go through tight spaces you can't normally get through. This can kill you if you try to do it near sand.
 * If a block is on the spawn, it will disapear when someone respawns or uses a magic mirror.

NPCs

 * NPCs continue to occupy a general area even if it is no longer 'suitable' for NPCs
 * The Dryad, Nurse, Arms Dealer, and Demolitionist sometimes fail to spawn, even though there are valid houses in the world. It seems this can happen to any NPC in the game.
 * Selling to a merchant (tested on arms dealer) when less than 100 silver coins in inventory but the sale brings you to over 100 silver, the silver rolls over back to 0 and you lose the 1 gold.
 * When the Nurse stands on a chest and right-clicked, her dialogue is brought up for approximately two seconds before the chest suddenly is opened.
 * NPCs sometimes have pathing issues when attempting to reach their rooms.
 * The Nurse charges more than what she asks for. (IE: She says 6 copper, she charges 9 copper instead)

Monsters

 * 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
 * Demon eyes can sometimes travel through 1 block thick dirt.
 * (v1.0.3) At high resolutions such as 1920x1080, monsters will not spawn to the left or right of you, only above/below you. This is probably due to how the game creates monsters off-screen and removes monsters that are too far away from you.

Map Generation

 * Jungle shrines can be generated in lava pools with no chest inside them. (Screenshot)
 * Jungle shrines can be generated in the sky (~15 blocks above the ground) (Screenshot)
 * Sometimes a huge amount of mud can be found at the surface if a jungle is close to the surface.
 * In some map instances, it may be impossible to find certain unique items.

Weapons

 * The Molten Fury is supposed to shoot Wooden Arrows as Flaming Arrows, but these arrows will still deal Wooden Arrow damage.
 * Boomerang/Flamarang can hit through walls if thrown at max distance. (More precise: the "Turnaround"-Animation can pass/hit through walls. When turning back, it can go through anything to get back to the owner.)
 * Thorn Chakrum can be thrown through 1 block thick walls if the player is in contact with the wall.

Walls

 * Sometimes the background("Wall") when underground (rocky and mud-rocky) will start to follow you and glitch, jerking about in random motions, there is currently no known fix to this bug. Although waiting for a Terraria update may help, for they reset all files on update.
 * Hellstone walls cannot be picked up. (taken from Hellstone Wall)
 * Dirt walls cannot be picked up.

Meteors

 * The lighting effect of a meteor crash site may remain even when all meteor blocks have been mined.
 * Meteors will crash onto very thin bridges of blocks, essentially wasting the event as there is usually not enough meteorite created to spawn meteor heads

Water

 * It is possible for a small puddle of water to turn into a never-ending waterfall when the bottom is dug out.
 * When large amounts of water are in motion, the server's performance can be brought down significantly.
 * An infinite pool of water can be made with an upside down "J" dug into the ground by placing water in the center, taking it out of the shallower side, and repeating.

Crash

 * 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, 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 cannot be retrieved although map files still exist.
 * When you read a sign, then destroy it, edit and save it. Your game will also crash

Gameplay Multiplayer

 * There seems to be a problem in the Client-Server synchronization causing monsters to suddenly teleport to another location when they are dealt damage by the player. This can make it dangerous to fight creatures online because they often teleport into the player, doing damage when the knockback should have kept the player safe from damage. Server specs don't appear to help this very much, so it's most likely caused by buggy net-code in the game. This is particularly noticeable for Meteor Heads.
 * Latency can cause items to not be picked up.
 * When the game crashes and the player returns to the server all existing chests in the game cannot be opened.
 * Multiple 'Nurse' may spawn when more than one person gets a life upgrade on the server.
 * Stars that fall but are unobtainable. Some work normally but there are some that fall in clusters of 2-3 next to each other but players are not able to grab them.
 * If you place a chest onto any block type, break it and try to replace it onto the same 2 blocks, it is unplaceable. The block type doesn't seem to matter. Relogging from the Multiplayer server seems to fix this issue.
 * If a client's program crashes or ends unexpectedly, the client's character won't save and will still have the same inventory that they had at the start of the session. This can result in items duplicating or disappearing entirely.
 * 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.
 * If you minimize the server window, the time goes faster (when clicking the server window button in the task bar, might only happen on Win 7/Vista.). It looks like the sun and moon "teleports" forward. And the monsters are super fast. Maximizing the server window fixes this.
 * Game may crash when you break 4 Shadow Orbs in a row.
 * 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.
 * The Eye of Cthulhu may fail to spawn when summoned.
 * Closed doors can sometimes appear to let people in when connected to a server due to poor handling of latency.

Visual

 * 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. The cursor also speeds up, this also affects single player. (multiplayer not known) It is widely 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.

Audio

 * Both the day theme and night theme 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 starts a new loop.

Item Cloning
Item cloning can 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 itemt, 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: OR
 * 1) Player A leaves item A 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 A and now has a duplicate.

OR
 * 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.

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 rightclick the spot were the gold originally was and obtain a gold ore, he can then proceed to rightclick 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 atleast one hellstone, it also renders musket balls useless as meteorite shots can be made on demand for just 6 ore per 100 shots, 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, droping any nameless items results in the item being randomly made into something else with the exact same number in the stack but is still nameless.

Flying Chest On Sand
For this glitch, you must place two columns of sand. Place a chest at the top of the sand, and destroy the sand under the chest. Flying chest!

Water eating Door
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.

Single Player

 * If an NPC opens your door and you continually right click it, the door disappears.
 * Parts of your home can disappear for no reason.
 * While playing on windows 7, with frame skip off and in windowed mode, click the Terraria task bar icon to minimise the window. This will cause the game to drasically speed up.

Multiplayer

 * The Eater of Worlds doesn't spawn after destroying 3 shadow orbs in a huge map.
 * Holding the mysterious looking eye will cause the Eye of Cthulhu to spawn, assuming the right conditions are met. The mysterious looking eye will not be used.
 * Holding Worm Food (having it in your active item slot) and standing in Corruption will spawn a Eater of Worlds automatically without using up the Worm Food. Eater of Worlds will not spawn if the Worm Food is not your active item.