  We show that an n-geometric stack may be regarded as a special kind of
simplicial scheme, namely a Duskin n-hypergroupoid in affine schemes, where
surjectivity is defined in terms of covering maps, yielding Artin n-stacks,
Deligne-Mumford n-stacks and n-schemes as the notion of covering varies. This
formulation adapts to all HAG contexts, so in particular works for derived
n-stacks (replacing rings with simplicial rings). We exploit this to describe
quasi-coherent sheaves and complexes on these stacks, and to draw comparisons
with Kontsevich's dg-schemes. As an application, we show how the cotangent
complex controls infinitesimal deformations of higher and derived stacks.
