Teleporter

You buy these from the Mechanic, which makes them a post-Skeletron toy, and one alone does nothing. A working link needs two pads sitting on solid ground or platforms, Wire running between them, and something to fire the signal, usually a switch or a pressure plate. Nothing about the trip costs you anything: no mana, no coins, no cooldown, no loading pause, and no cap on how far apart the two pads sit. Underground, in the air, across the entire map, it is the same instant hop.

The pad itself is three blocks wide and behaves like terrain rather than furniture. You can hammer it into half height, actuate it, and stack other blocks or furniture on top without breaking anything, since objects sitting on a pad neither travel nor block the people who do.

Anything overlapping the three by three square above the pad goes, which is more forgiving than it looks. You can stand a couple of tiles up and still get taken, you can bury a pad below the floor and have it grab anyone walking over that spot, and a hammered pad under a platform will catch someone standing beneath the platform. Whatever offset you had when you left is the offset you arrive with, so a player two tiles above the sending pad appears two tiles above the receiving one. That is worth planning around when the far end is inside a tight shaft.

Both ends empty into each other at once. Whatever is standing on the far pad arrives where you were standing, and that absolutely includes enemies. Use a pad as your front door and sooner or later something walks onto the outside end at the wrong moment and lands in your bedroom. If a plate is doing the triggering, use one of the colors that only reacts to players and never to monsters.

Each end of a pad takes its own wire color, so one pad can serve several routes at once if you keep the colors straight, and a handful of pads on a shared network can reach dozens of destinations. Once three or more pads sit on the same color, the game picks the closest and the farthest along the wire and fires those two, ignoring anyone standing on the ones in between. Distance here is the length of the wire path from the trigger, not the distance across the map, and the whole thing is deterministic, so the same layout always sends you to the same place.

That turns wire length into the control lever. Loop a run the long way around and it becomes the farthest pad on the network. Put a second switch elsewhere on the same wire and it will have a different farthest pad, which is how you get several destinations out of one color. Keep red out of it when you are building underground, since the temple traps run on red and you will be setting those off from across the world.

Two pads with plates on both is a dodge button that never runs out, and jumping between them dodges attacks nothing else in the game can avoid. Offset the plates to one side of each pad, alternating sides, so that landing does not immediately fire the return trip. Pads work while you are riding a minecart too, which lets you bridge two unconnected track lines across a canyon you never bothered to dig through. One thing to expect: teleporting drops every hook you have out, and in multiplayer the trip goes through the server, so it is not truly instant.

The ignore list is long. Bosses, worms, anything that travels through blocks, critters, liquids, dropped items, placed furniture, pets and light pets, and everything from the Old One's Army all stay put. A pad also refuses to work at all when it is placed against unsafe temple walls until Plantera is dead, so no skipping the front door. A player above sensor will not move players either, which catches people out when they try to build an automatic pad.

Teleporting at night to somewhere at least a screen away makes any townsperson who has not yet walked to their assigned house appear in it immediately, which beats waiting for them to path there. And stacking two pads, placing furniture on the upper one, then breaking the lower will leave the furniture floating in mid air, since the upper pad breaks without taking its passenger with it. Echo Blocks and echo platforms do the same job more cleanly now, but the old trick still works.