Terraria Wiring Planner and Simulator
Plan Terraria wiring on a grid: wires, actuators, logic gates, timers and junction boxes, then simulate signals and get a wire and parts list.
Plan Terraria wiring on a grid before you spend wire in your world. Paint red, blue, green and yellow wire, drop in switches, timers, logic gates, doors, torches, teleporters, junction boxes, dart traps and actuators, then switch to Simulate and click a switch to watch the signal travel and see what it toggles. It also counts your wire and parts. The simulation follows the wiring rules described on the Official Terraria Wiki for version 1.4.5.8.
How to use the wiring planner
- Pick Wire and a colour, then drag across the grid. Wire only joins the four tiles beside it, never diagonally, and different colours never connect to each other.
- Pick Place and choose a component from the list. Logic gate lamps must go directly on top of a logic gate or another lamp, just like in the game.
- Use Block to place solid blocks, then Actuator to put actuators on them.
- Use Hammer to change how a junction box routes wire, turn a dart trap, or choose which side a door swings to.
- Use Select to drag a box around part of your circuit and move it. Undo and Redo (Ctrl+Z / Ctrl+Y) cover every edit.
- Untick a colour to hide that wire layer.
- Press Simulate. Click a switch, lever or pressure plate to send a signal. Click a timer to turn it on or off. The signal log lists what each signal reached.
- Press Make save code and keep it. Paste it back and press Load code later.
The examples menu has seven ready-made circuits to start from.
How a wiring signal works
When a switch, lever, pressure plate or timer triggers, the game sends a signal along every wire colour that touches the trigger. The colours are handled one after another (red, blue, green, yellow). Each colour spreads through every connected tile of that colour, and every mechanism on a reached tile is activated once. Two details matter for planning:
- The trigger's own tiles are not activated by its own signal.
- If the same device is reached by two colours from one trigger, it is activated twice, so a torch wired to a switch with both red and blue ends up where it started.
| Component | What a signal does in the planner |
|---|---|
| Torch, Lamp | Turns the light on or off |
| Door | Opens if closed and there is room, closes if open. Wire on the hinge column toggles it; wire only on the swing side can only close it |
| Actuator (on a block) | Switches the block between solid and inactive |
| Timer | Turns it on or off. A running timer sends a signal every 1, 3, 5, 1/2 or 1/4 seconds |
| Logic gate lamp | Flips the lamp between on and off |
| Dart trap | Fires, then needs 200 ticks (3 1/3 seconds) before it can fire again |
| Teleporter | Swaps whatever stands on the two linked pads |
| Junction box | Lets same-colour wires cross. Hammer it to make it turn corners instead (top–left plus bottom–right, or top–right plus bottom–left) |
Logic gates and lamps
Logic gates read the stack of logic gate lamps directly above them. AND turns on when all lamps are on, OR when at least one is on, NAND unless all are on, NOR when none are on, XOR when exactly one is on (even with three or more lamps), and XNOR when the number of lit lamps is not one. A gate sends a signal every time it turns on or off, which is why the game has no NOT gate.
A gate can only send one signal per tick. If its own output flips its lamps again in the same tick, the gate still changes state but the second signal is lost and you see a puff of smoke. The planner reproduces this and reports it in the log. A faulty lamp on top of the stack turns the gate into a randomiser: each time the faulty lamp gets a signal, the gate sends a signal with a chance equal to the share of lamps below it that are on.
Timers and teleporters
A timer sends its first signal one full interval after it is switched on. If one timer turns on a second timer of the same length, the second one fires first and switches the first one off, which is how timer cascades work. Clicking a timer by hand turns it on or off without sending a signal.
When one wire colour reaches more than two teleporters, only two are linked: the one closest to the trigger along the wire and the one farthest away.
What the planner leaves out
The planner shows signals, not physics: nothing is teleported or damaged, and all pressure plates are one generic plate. Sensors, statues, pumps, explosives and other traps are not included. In the game the side a wire-triggered door opens to depends on the space around it; the planner lets you choose the side with the hammer instead. Prices are the wiki's base buy prices, and NPC happiness changes what you pay.
Frequently asked questions
How many wires do I need in Terraria?
You need one wire item per tile per color. The materials panel counts every tile of each color separately, so a tile carrying red and blue costs two wire.
Why does my torch not change when I flip the switch?
Two colors from the same switch probably reach it. Each color toggles it once, so they cancel out.
Can two red wires cross without connecting?
Yes, put a junction box on the tile where they cross. Without one, the wires join.
Why did my logic gate puff smoke?
Its output changed its own inputs again in the same tick. A gate only sends one signal per tick, so the extra change happens without a signal.
Where do I buy wiring parts in Terraria?
Most parts come from the Mechanic. Logic gates and lamps come from the Steampunker in Hardmode.
How do I save my wiring design?
Press Make save code and keep the code somewhere safe. Paste it back into the planner and press Load code to open the design again.