  Hydrogen-rich (type II) supernovae (SNe) exhibit considerable photometric and
spectroscopic diversity. Extending previous work that focused exclusively on
photometry, we simultaneously model the multi-band light curves and optical
spectra of Type II SNe using RSG progenitors that are characterized by their
H-rich envelope masses or the mass and extent of an enshrouding cocoon at the
star's surface. Reducing the H-rich envelope mass yields faster declining light
curves, a shorter duration of the photospheric phase, broader line profiles at
early times, but only a modest boost in early-time optical brightness.
Increasing the mass of the circumstellar material (CSM) is more effective at
boosting the early-time brightness and producing a fast-declining light curve
while leaving the duration of the photospheric phase intact. It also makes the
optical color bluer, delays the onset of recombination, and can severely reduce
the speed of the fastest ejecta material. The early ejecta interaction with CSM
is conducive to producing featureless spectra at $10-20$ d and a weak or absent
H$\alpha$ absorption during the recombination phase. The slow decliners SNe
1999em, 2012aw, and 2004et can be explained with a $1.2 \times 10^{51}$ erg
explosion in a compact ($\sim$600 R$_\odot$) RSG star from a 15 M$_\odot$
stellar evolution model. A small amount of CSM ($<0.2$ M$_\odot$) improves the
match to the SN photometry at times $<$ 10 d. With more extended RSG
progenitors, one predicts lower ejecta kinetic energies, but the SN color stays
blue for too long and the spectral line widths are too narrow. The fast
decliners SNe 2013ej and 2014G may require $0.5-1.0$ M$_\odot$ of CSM, although
this depends on the CSM structure. A larger boost to the luminosity (as for
fast decliners SNe 1979C or 1998S) requires interaction with a more spatially
extended CSM, which might also be detached from the star.
