A base is the rigid piece of plastic that the unit card will sit on and the figures fit into. A base can be formation (rectangular) or sortie (square) size.
- Notch: Notches are used for measuring. Whenever a distance is measured from (or to) a unit, it is measured from (or to) a notch.
- Peg Holes: Figures have pegs on the bottom of their footpad. The pegs will fit snugly into the peg holes on a base in order to hold that figure in place.
The basic unit of measurement in Arcane Legions is the step. A step is the length of a sortie base, which is also the length of the short side of a formation base. (The long side of the formation base is two steps.)