  We here focus on the behavior of supernovae that technically explode in 1D
(spherical symmetry). When simulated in 3D, however, the outcomes of
representative progenitors of this class are quite different in almost all
relevant quantities. In 3D, the explosion energies can be two to ten times
higher, and there are correspondingly large differences in the $^{56}$Ni
yields. These differences between the 3D and 1D simulations reflect in part the
relative delay to explosion of the latter and in the former the presence of
proto-neutron star convection that boosts the driving neutrino luminosities by
as much as $\sim$50\% at later times. In addition, we find that the ejecta in
3D models are more neutron-rich, resulting in significant weak r-process and
$^{48}$Ca yields. Furthermore, we find that in 3D the core is an interesting,
though subdominant, source of acoustic power. In summary, we find that though a
model might be found theoretically to explode in 1D, one must perform supernova
simulations in 3D to capture most of the associated observables. The
differences between 1D and 3D models are just too large to ignore.
