Gonzalo Frasca
" A voluntary activity or occupation executed within
certain fixed limits of time and place, according to
rules freely accepted but absolutely binding, having
its aim in itself and accompanied by a feeling of
tension, joy, and the consciousness that it is
different from ordinary life. (Huizinga, 1968)

Many elements emerge from this definition. Firstly,
that it is an activity that the player volunteers to
perform and, therefore, she is able to quit at will.
According to this definition, play has both time and
space constraints. Rules appear as essential
elements and the whole activity is described as
being performed by acknowledging it as different
from reality."