Mechanical Ruler

Type	AccessoryCrafting material
Tooltip	Creates measurement lines on screen for block placement
Rarity
Buy	1 GC
Sell	20 SC
Research	1 required

Desktop/Console/Mobile-Only Content: This information applies only to the Desktop, Console, and Mobile versions of Terraria.

Toggle icons for the
Mechanical Ruler

The Mechanical Ruler in action.

The Mechanical Ruler is an informational accessory that, when equipped, draws a cyan, semi-transparent grid overlay on the screen, making individual block distances much clearer. This grid fades out when the player begins moving and returns once movement stops. The row and column of the block the mouse is hovering over are also highlighted in red, drawing a cross on the screen with the cursor at its center. The Mechanical Ruler can be purchased from the Mechanic for 1 GC.

When the Mechanical Ruler is in the inventory or equipped, a toggle for controlling its function appears to the left of the main inventory / in the tools menu below the inventory.

Crafting

Used in

Result	Ingredients	Crafting station
The Grand Design(Desktop, Console and Mobile versions)	Multicolor Wrench(Desktop, Console and Mobile versions) Mechanical Lens(Desktop, Console and Mobile versions) Mechanical Ruler(Desktop, Console and Mobile versions) Wire60	Tinkerer's Workshop

Notes

Unlike most accessories, informational accessories such as the Mechanical Ruler do not need to be equipped in an accessory slot. The Mechanical Ruler may be carried in the player's inventory without loss of functionality, unless equipped to a social slot. Keep in mind modifiers will no longer apply to the player when not equipped.
Though it has very little utility in combat, the Mechanical Ruler can still receive a modifier and affect the player's stats.
Having the Mechanical Ruler equipped in a social accessory slot disables the item. Having it equipped in an active accessory slot enables the item's functionality even when the slot is set to be invisible.
The game's "Tile Grid" setting creates a less obtrusive five-block wide grid around the cursor, which can be useful if one finds that the Mechanical Ruler's overlay is too distracting.