  In [3] Borzellino and Brunsden started to develop an elementary differential
topology theory for orbifolds. In this paper we carry on their project by
defining a mapping degree for proper maps between orbifolds, which counts
preimages of regular values with appropriate weights. We show that the mapping
degree satisfies the expected invariance properties, under the assumption that
the domain does not have a codimension one singular stratum. We study
properties of the mapping degree and compute the degree in some examples.
