  In recent years, there has been a proliferation of online gambling sites,
which made gambling more accessible with a consequent rise in related problems,
such as addiction. Hence, the analysis of the gambling behaviour at both the
individual and the aggregate levels has become the object of several
investigations. In this paper, resorting to classical methods of the kinetic
theory, we describe the behaviour of a multi-agent system of gamblers
participating in lottery-type games on a virtual-item gambling market. The
comparison with previous, often empirical, results highlights the ability of
the kinetic approach to explain how the simple microscopic rules of a
gambling-type game produce complex collective trends, which might be difficult
to interpret precisely by looking only at the available data.
