Tripwire

In Minecraft, a tripwire is a redstone mechanism consisting of tripwire hooks and string. Tripwire hooks are items placed on the sides of solid blocks, while string (made from yarn) connects two tripwire hooks. When a creature or item passes through the string, the tripwire circuit is activated, emitting a redstone signal and powering its attached blocks. This signal can be used to trigger traps, open doors, or activate other redstone contraptions. Tripwire hooks can be crafted or found naturally in locations like jungle temples. They can also be obtained through fishing, but are classified as "junk". Tripwire is a useful mechanism to create a variety of complex traps and automatic devices. The tripwire system in Minecraft was introduced in version 1.3.1, becoming a staple of the game's redstone mechanics. The tripwire itself does not provide redstone power, but the tripwire hooks provide power to the blocks they are attached to. The tripwire can be safely disarmed with shears, otherwise, it will emit a short current. Tripwires are available in all versions of Minecraft, although their behavior may slightly differ between versions.