Ruler

The Ruler is an accessory, which when equipped, shows a white grid overlay making intricate construction easier.

The Ruler can be bought for from the Goblin Tinkerer. (Note that the Ruler's grid effect may quickly become annoying as the grid can get in the way of other items/furniture.) This item is often used to help in building for symmetrical structures.



Trivia
In real life, a ruler is used to measure the length or width of an object. They are also commonly used in construction work or mathematics.