Practical Units

General information

Location

The character's absolute position is given by the command

/loc

which returns information in the form

Your position: x,y,z:X,Y=M

where

Legend for /loc command output

values	meaning	range
M	map ID	Only maps 65 and map 66 are in use.
X,Y	region coordinates within map	-127..127
x,y,z	pixel offsets from top-left of region	x,y are in the range 0..255. z is a non-negative integer corresponding to the elevation above ground level on which the character stands. It is typically a multiple of 8, which is the height of a half-block.

Cell

Visualisation of a cell. The yellow area shows its lower extent.

An absolutely positioned square column corresponding to the horizontal area in which a block can be placed, vertically extended to the map limits.

It is the basic unit of land possession; no more than one player can place blocks in the same block unless within a town set up to allow it.

The top left corner of a block is registered to x and y pixel offsets that are multiples of 16.

Region

A 16x16 block area identified by the same coordinates. See also, Geography.

Length

Span

The length of a block's horizontal edge. Graphically, 16 pixels.

Step

The height of a half-tile as well as the height difference a character can climb by walking. It is the basic vertical unit applicable to construction. Graphically, 8 pixels.

Note: A half-step is the smallest vertical unit that can be used precisely in-game, requiring the use of low tables or signs. EDIT: As of a later build occuring in April 2014 Signs now position themselves in the centre of a block.
Quarter-step differences are possible only by using a townstone, player character or telepads.

Other Units

These units have no broad application or acceptance, but may serve as useful alternatives at different scales or when writing fiction.

Furlong

An imprecise unit of distance defined for convenience as a region difference of 10 in whichever of x or y directions the difference is greatest, ignoring finer divisions.
It is approximately 30 seconds walk on open ground.

In contexts requiring precise lengths, it is equal to 160 spans.

THIS UNIT OF MEASUREMENT IS NOT USED ANYMORE AND IT IS NOT RECOMMENDED TO REFER TO IT IN CHAT. many players would not understand you and you may waste time :)