  The extraction of two- and three-body hadronic scattering amplitudes and the
properties of the low-lying hadronic resonances from the finite-volume energy
levels in lattice QCD represents a rapidly developing field of research. The
use of various modifications of the L\"uscher finite-volume method has opened a
path to calculate infinite-volume scattering amplitudes on the lattice. Many
new results have been obtained recently for different two- and three-body
scattering processes, including the extraction of resonance poles and their
properties from lattice data. Such studies, however, require robust
parametrizations of the infinite-volume scattering amplitudes, which rely on
basic properties of $S$-matrix theory and -- preferably -- encompass systems
with quark masses at and away from the physical point. Parametrizations of this
kind, provided by unitarized Chiral Perturbation Theory, are discussed in this
review. Special attention is paid to three-body systems on the lattice, owing
to the rapidly growing interest in the field. Here, we briefly survey the
formalism, chiral extrapolation, as well as finite-volume analyses of lattice
data.
