An oriented lattice is a point lattice 
equipped with a graph structure
and a rule assigning a direction to each edge connecting
lattice points. In that way, an oriented lattice
is intimately connected to an oriented graph.
Given a point lattice 
with edges joining nearest neighbors
along the coordinate axes,
one common such rule is the so-called north-east rule, which directs each edge
in the direction of increasing coordinate value.
This type of oriented lattice is central in a number of fields, e.g., in oriented
percolation models within the field of discrete
percolation theory.
