In physics, the concept of universality allows to group a great variety of different critical phenomena into a small number of universality classes in such a way that all systems belonging to a given universality class are essentially identical near the critical point. Thus, systems belonging to the same universality class, even if defined by very different material parameters or physical properties, have the same critical exponents characterizing diverging observables. For example, in different spin and percolation models, we find that the family of all bidimensional lattices (square, triangular, hexagonal and so forth) spatial correlations follow the asymptotic form c(r) ∝ 1/rη near the phase transition point, where η is the same for all lattice structures of dimension 2 in a particular model.