\section{Introduction}

\hspace{1.0em} Geant4 currently offers both a parameterized fission model 
and a data-driven fission model.  The parameterized model predicts the 
final excited fragments which result from the symmetric or asymmetric 
fission of an excited nucleus.  This model is considered as a competitor
to the evaporation process for nuclei with atomic number $A \geq 65$.
Here, the final state generation is discussed, while the calculation of 
the relative probability of fission with respect to evaporation channels 
is described in the chapter on evaporation.

An alternative, data-driven model describes neutron-induced and spontaneous 
fission and was developed at Lawrence Livermore National Laboratory.  It has
improved multiplicity sampling and is based on a collection of empirical 
models.  These models and the data upon which they are based are discussed.