Slope
Slope is the angle/incline a tile is set at. Slope can be determined by examining a tile border. It is usually expressed in 'dirts', which is the number an examination of the tile border returns.
Other
Since the new update, when you have a shovel equipped you can see the slope of a tile by hovering your mouse over the tile border( Or the tile if its flat ).
Maximum slope before you will start to fall down is 20.
