  Bubbles of nothing (BoNs) describe the decay of spacetimes with compact
dimensions and are thus of fundamental importance for many higher dimensional
theories proposed beyond the Standard Model. BoNs admit a 4-dimensional
description in terms of a singular Coleman-de Luccia (CdL) instanton involving
the size modulus field, stabilized by some potential $V(\phi)$. Using the
so-called tunneling potential ($V_t$) approach, we study which types of BoNs
are possible and for which potentials $V(\phi)$ can they be present. We
identify four different types of BoN, characterized by different asymptotic
behaviours at the BoN core and corresponding to different classes of higher
dimensional theories, which we also classify. Combining numerous analytical and
numerical examples, we study the interplay of BoN decays with other standard
decay channels, identify the possible types of quenching of BoN decays and show
how BoNs for flux compactifications can also be described in 4 dimensions by a
multifield $V_t$. The use of the $V_t$ approach greatly aids our analyses and
offers a very simple picture of BoNs which are treated in the same language as
any other standard vacuum decays.
