Gray Pressure Plate

Every pressure plate does the same job, and the color is the filter on who can set it off. Gray, red, brown, orange and lihzahrd plates are the ones the world generates on its own to arm its traps, and the game picks whichever color matches the block underneath, which is why gray is what you find sitting on stone. They take up almost no visible height on top of a block and stepping on one without noticing is genuinely easy. A Dangersense Potion marks them out, and simply holding any pressure plate in your hand reveals laid wire straight through terrain, which is the fastest way to read a trapped corridor before you commit to walking it. That second trick is switched off in For the Worthy and Zenith worlds.

The Mechanic stocks everything except the lihzahrd type. The obvious use is a door that opens itself, and the thing to get right is the filter: pick a color that only answers to what you want, or the door flaps every time a bunny hops past. Plates that accept non player triggers also answer to boulders, which is a cheap way to build a delay or to set off a whole row of traps as one rolls down a hallway. Paint disguises a plate and Echo Coating removes it from view completely, which is mostly a PvP tool. A plate placed on top of a block still works under reversed gravity if you fly up into it.

Weighted plates fire twice, once as they go down and once as they come back up, which makes them the natural pick for a door that should shut behind you. The catch is that all weighted plates of one color share a single pressed state across the entire circuit. If one of them is already held down somewhere, standing on another of the same color sends nothing at all. Any circuit that needs several of these needs several colors.

The Teal Pressure Pad ignores feet and answers to projectiles instead. It does not need to be hit accurately, only crossed, and the definition of projectile is generous. Golf balls count. A pet brushing against it counts. Falling stars dropping out of the night sky will set one off with nobody present at all, which is worth planning around before you wire one to something loud. It also mounts on any face of a block, ceilings and side walls included, which no other plate does. Wire one to a Dart Trap pointed back at it and you have a working delay circuit long before logic gates are available.