Active Stone Block

Active Stone Blocks and Inactive Stone Blocks are blocks that act as Mechanisms, such that when they are Wired, their presence can be switched on or off.

When triggered, an Active Stone Block becomes an Inactive Stone Block, and vice-versa. Wires must pass through all Active/Inactive blocks that are to be triggered, and the wires must connect to a trigger, such as a Pressure Plate, Switch, or Timer. These blocks are useful for creating traps, floodgates, hidden passages, drawbridges (eg. over water, lava, or empty space), skybridges, and much more.


 * While in their Active state, these blocks look and behave as ordinary Stone Blocks, inhibiting movement, allowing entities to stand or walk on them, blocking light, and containing liquids.
 * When in their Inactive state, they are still visible, but look and behave instead as background Stone Wall tiles. They are essentially empty space, allowing the passage of players, items, liquids, light, etc.

Both the Active and Inactive phases can be crafted. Players will usually want to craft the Active version, as the Inactive blocks cannot be placed next to each other without the support of other adjacent foreground blocks. Active blocks do not have this shortcoming, and switching them to Inactive afterwards using wires will still provide the same outcome.

Placing Active Stone Blocks, switching them to Inactive with wiring, then mining them and picking them up again, will cause you to pick up Inactive blocks, and vice-versa.

Active/Inactive Stone Blocks occur naturally in Boulder traps found in the Cavern layer, where Active blocks that are wired to Pressure Plates suspend a Boulder in the ceiling. An enemy or player walking on the Plate cause the Active blocks to turn Inactive, allowing the Boulder to fall through and damage whomever is below.

Tips

 * Even without a mechanic (required to obtain wiring tools), this item still has use if harvested from naturally-occurring Boulder traps underground. You can select this item in your toolbar to see a layout of all wires on screen, which is useful for detecting and avoiding natural traps.
 * A vertical strip of three Active Stone Blocks wired to a nearby Switch or Lever serves as a good alternative to Doors that only players can open. NPCs won't be able to use them to stray outside, and no enemy can ever open them. Note that this will not fulfill a House's entrance requirement, so at least one actual Door will still be required in order for an NPC to move in (though the Door need not lead "outside", and can merely open into another room of a larger structure).
 * Note that the Clown in Hardmode can destroy Active Stone Blocks with their bombs.
 * To conserve storage space, consider switching all Inactive Stone Blocks to Active Stone Blocks, or vice versa. This can easily save an inventory or storage slot by combining the stacks.

History
Активный каменный блок