There are many types of Traps you can make in Terraria, for NPCs and players alike. Listed are commonly encountered ones.
Lava TrapThis is the most basic trap. It's a pit with lava in it. The lava will not burn up loot if there is very little lava. A 10 block wide pit with only 1 bucket of lava will work perfectly. These traps are good for home defense during goblin invasions as they can be left unattended and visited later to collect the treasure.
If you want to have a collection point underneath your trap, giving you safety from the lava.
Lava "Wall" Trap
This trap is similar to the basic lava trap but instead of spanning a horizontal distance it will cover a vertical space. One of the nice features about this lava trap is that you can turn it off, allowing for safe passage rather than having to remove the lava manually. The disadvantage, however, is that there is a good chance any loot dropped by enemies will be exposed to the lava and burn up. But if your goal is to simply keep most enemies out while still being able to pass through it yourself (harmlessly if protected by an Obsidian Skin Potion), then this trap will be very effective. It makes use of the new 1.1 mechanics so you will need a bucket of lava (or more depending on the height you are trying to cover), an Inlet Pump, an Outlet Pump, a Wrench and some Wire, and a 1 Second Timer.
Warning: Sometimes this trap glitches while you are off screen. It is unknown what causes this but when you return the Lava will have either overflown or disappeared completely. Sometimes lava will spill while falling, causing it to land on the ground next to where it was intended to and cause damage to the surrounding area. It is suggested that you only activate this trap if you are staying in the immediate area.
You start by placing the inlet pump at the bottom of where you want the wall the be and the outlet pump as far above it as you want the wall's height to be. Place blocks around both pumps except for the part that you want the lava to fall from/into. You can dig little nooks into the area where you want the wall to be so they don't stick out since players are able to walk over holes 1 block wide. Attach both pumps to a 1 second timer and add lava to the inlet pump at the bottom. Wires are not affected by lava so don't worry about damaging them. Activate the timer either by right clicking it or attaching it to something else like a lever. The lava will now pump out from the top and will fall back down to the inlet endlessly as long as the timer is active.
Optionally you can add an active/inactive stone block to the hole at the top where the outlet is so that the lava will stop flowing faster when you turn it off, but attach it to something other than the timer. Otherwise you have to wait for the lava at the top to drain out.
This is a modification of the lava trap, with a tunnel built underneath it to collect the loot without having to touch the lava.
Made by placing a wall then dropping sand on top of it, then when the enemy you want to kill is underneath, break the wall and let the sand fall on top of them. While this is effective to some degree against slimes, the setup and cleanup are not worth the loot you will get and you will have to dig to get to it. Warning: Falling sand can hurt and kill given the opportunity.
Place a Torch with sand stacked on top then put a torch on the side of the bottom-most piece of sand, and keep repeating the process until you have the pit the size you want. When you want to activate your trap remove the bottom torch and all stacks of sand will fall and damage enemies.
Flying Enemy Cage (a.k.a. Wooden Platform Trap)Wood Platforms on the floor of the trap. This ensures that slimes and flying enemies, such as Demon Eyes, can enter the trap by passing through the wooden platforms from below, but they won't be able to leave it since they can't pass through wooden platforms from above. Although this trap isn't lethal by itself, it can be used to keep the trapped enemies from bothering you.
- Note that, as of patch 1.0.6, Bats, Harpies, Demons, etc. can now pass through wooden platforms, making these traps ineffective against them.
Build your bridge at sea level, and then place wooden platforms under the sections you want to replace with the trap. Once removed, lava can be added without burning the platforms or turning into obsidian. Build a safe room above the trap, and pour two buckets full of water inside to lure the Sharks and Jellyfish into your trap. They will attempt to chase after your through the wooden platforms, only to end up being roasted by the lava. This trap was patched in the 1.2.3 update of Terraria.
Simply all you need is 2 dart traps, wire, and 2 pressure plates. The dart trap is wired to the pressure plate in front of it a few blocks away. With these on both sides of the house, some invading monsters will be slain. However, this will not slay all of them. It is helpful when defending your house on blood moons. But, if you stacked several dart traps up so that more than 1 dart shoots at once, it might be a lot more helpful.
They can also be set up with a 3-second timer linked to a Switch to fire automatically; a volley of 4-5 arrows will be more effective against monsters, especially if they're being slowed down by other traps.
- Does not kill all enemies
- Slow (3 second delay)
- Can kill NPCs
- You don't have to be in the immediate area
- Can be set to be completely "handsfree"
This trap involves Active Stone blocks, a lever and some wire. The trap is simple, You build a box out of active/inactive stone blocks and then hook up a lever to it. Then, when someone or something comes around, you pull the lever, trapping them. The blocks can be mined, however, so this is a delaying tactic.
Combine with boulders and / or explosives for lethality.
To make the cage passive, use a pressure plate ontop of an active stone block so when it's activated, the pressure plate becomes a dropped item, preventing the cage from being unlocked.
A combination of Active Caging and a Lava "Wall" Trap. Simply make a wall of active stone blocks on either side of a lava wall (or 2 or more) and then, when someone comes along, pull the lever. If using an active stone block plug, attach it to the lever used to make the walls appear. The plug must be active when the cage is inactive.
Lava ShowerThe lava shower is an alteration on the lava caging that is set to be automatic by the use of pressure plates (the button was added for testing), like the lava cage and the lava wall it usually destroys loot, however it does serve as an effective defense (tested on bunnies). The walls remain closed and when the exterior pressure plate is activated they open, closing again on the press of the second, this traps one mob and activates the pumps which with the lava's added effect of fire debuff can kill a player with 400 health and full adamantite armor. Another thing to note is that the right activating stone wall is not necessary or recommended as multiple mobs may get through.
Multi-Boulder Roll-out towerThe Multi-Boulder Roll-Out Tower is a trap designed for use on flat terrain or downhill slopes. The boulders are placed on active stone blocks and triggered by either a pressure plate or switch. When the active stone blocks are deactivated, the boulder will run over the pressure plates connected to the other boulders. The boulders fall onto the dirt block (or any other type of block, but has to only be one and not too far below the boulder), then roll off and keep rolling until they hit a block.
This can be useful for dealing large amounts of damage to large groups of mobs. However, since players have a brief invincibility after being hit it is ineffective in PVP. The boulders are also destroyed after one use so maintenance can be tiresome/costly.
(note: multiple boulders can be stacked on top of each other and triggered all at once when the boulder at the bottom falls.)
Single Boulder Roll-outThis is an alteration to the multi-boulder roll-out which changes it so that the boulders can be released individually, this makes it effective for sending the next after a delay to let the target players invincibility wear off. However, this means that they must be released manually or using lots of wire attached to different pressure plates (If you were going for PVP they would probably avoid the trap, unless in a three block high tunnel. (Also, the boulders themselves activate the pressure plates). The photo also shows how the trap can be placed on the outside of walls allowing for fast, safe and easy re-usage during an invasion.
Beware, the boulder can kill your NPC, even yourself if you're not careful.
LandmineThis is a basic (and costly & impractical) trap that utilizes the Explosive (item) block. Bury the explosive 1 block under the surface, run Wire from the explosive to 1 block above the surface and place a Pressure Plate directly above the explosive. When activated it will explode and leave a large crater in its wake, you can deactivate the mine by removing the wire. The aftermath of an exploded landmine can be annoying to repair and if left activated, is often triggered by the occasional Bunny or Slime Monsters that roam the area, so only activate it when you need to (like on a Blood Moon). You can improve it by placing a lava pit underneath it so it can continue being effective until replaced.
However, if used in PvP, it's recommended to bury explosives deeper, so enemy players can't see them.
Triggered Explosive CarpetEssentially, it is a group of Explosive (item) wired up to a Lever (or Switch). Like the Land Mine, you place them underground but this time you start wiring the explosives and connect them to a lever or switch. Make it as long as you desire, making sure to spread out the explosives evenly for the best area of effect or tightly packed for use against burrowing monsters like The Destroyer. This is not the best choice for home defense because once again it will leave a huge crater for you to clean up, this is better used against a large group of enemies (like snowmen from Frost Legion) or burrowing bosses.
Flying Boss BusterThis is a trap designed to target powerful flying enemies, such as Skeletron or The Twins. It's composed of a group of Explosives above ground, concealed in a box and wired to a Lever. It's similar to the Triggered Explosive Carpet but more tightly packed and above ground. As such, it can be tightly packed for maximum power or spread out for a larger blast radius. To use, simply lure the monster over to the explosives and pull the lever. Make sure the lever is far enough from the Explosives that you aren't damaged yourself. You can add as much explosive as you deem necessary.
Wired Sand Trap
Much like the sand trap this is used for dropping sand on your foes and suffocating them. Using active stone blocks instead of a block you just break. This trap can be automatic using a pressure plate hooked up to all the active stone bricks. The active stone bricks keep the sand up (you should have at least 2 sand blocks) and when the pressure plate is stepped on, the sand comes crashing down on them. If you have a long line of sand, you can use it for blood moons or goblin raids. The downfall to this trap however is the amount of cleanup afterwards not always the most convenient.
Underwater dart/loot trap
Similar to the dart trap this consist of a 5x10 underwater pit. The pit itself is lined with Dart Traps on the sides. The traps are connected to Red Pressure Plate/or color of your choice. Since the pit is full of water, it slows the enemies and is easier to hit them with projectiles from above if you so choose. Another important part of this trap is the 3x10 tunnel single block underneath. If your character runs underneath of this the loot will be collected through the 1x10 ceiling above you. This trap is useful for large mobs or bosses similar to the King Slime. It is also possible to create a bridge over the pit with Active Stone Blocks, this can also be used to cage your enemies inside. This trap is similar to the above dart trap and loot trap. (The picture shown here is an enlarged version).
Flickering Bridge Trap
Make a bridge made of Active Stone Blocks, hook up the wired stone blocks to a 1 Second Timer, 3 Second Timer, or 5 Second Timer, that repetitivley flickers the bridge, and when a non-flying mob, such as a Zombie or a Slime walks onto the bridge, it falls down into the moat/pit. You can place a lava floor at the bottom to kill the mob, but not burn the loot.
Spiky Ball Trap
Either end of a Pressure Plate place Spiky Ball Traps connected with wire to pressure plate so falling spiky balls will damage and stop monsters, players and even NPC's if you wish escaping from knockback. Works only with ground monsters such as Zombies unless on Timer. During invasion (i.e. Frost Legion) a good idea would be to set on 5 Second Timer because spiky balls drop at a rate of four seconds. If you have enough traps and is on timer this would work well against a burrowing monster such as the Eater of Worlds.
Fishhook TrapThis trap uses the ledge-walking feature from 1.2 (allows you to walk up 1 block stairs with ease, or 2 if properly set up). This trap is therefore not suitable for anybody who wants to stay in 1.1. This trap is only for human-sized enemies (zombies, goblins, even players) and some of the smaller mobs (e.g. bunnies and squirrels seem to get stuck in it), and will not work on larger enemies. One of the advantages of this trap is that it can be made out of any solid material, even out of dirt, snow blocks or wood, so you can basically dig up some dirt and create this trap.
If you want to get fancy, you can place an Actuator on the tip of the "hook" and wire it to a switch (or better yet, a player-only Pressure Plate) inside the trap to be able to get out easily if you accidentally trap yourself while collecting dropped loot.
Traps For Invasions
First thing you want to do is to place traps, (i.e. Lihzahrd Temple traps) Then wire them up to switch or 3 sec repeater (It works the best) go inside and block the doors so nothing can get in. then summon the invasion (i.e. Frost Legion) and click repeately the switch or just turn on the repeater. Now it is ready. Recommended traps to use: Spiky Ball Traps, Flame Traps, and Spear Traps.
This trap is made out of traps that are found in the Lihzahrd Temple (i.e. super dart traps), only after you have killed Plantera. Works epicly efficiently vs bosses. You can kill The Destroyer under 30 seconds and with a little modification it could be made to be efficient vs any boss.