  We describe the simulation of tau decays in the Herwig++ event generator,
which includes sophisticated modelling of the hadronic currents and full
treatment of spin correlation effects. The structure of the simulation makes it
easy to add new models of tau decay,change the parameters of the existing
models, and use the models from tau decay for the decay of other particles. The
results are compared in detail with an existing simulation, and the benefits of
the new structure are illustrated by considering the decay of the lightest
chargino to the lightest neutralino in Anomaly-Mediated SUSY-Breaking models.
