There is overwhelming evidence for the existence of dark matter in the Universe.
However, while its energy density today is measured with unprecedented precision,
its microscopic properties and possible non-gravitational interactions with the standard
model remain elusive. Accordingly, a plethora of particle dark matter models exist that
explain the observed abundance. In this talk we review some of the rules and exceptions in the calculation of the dark matter density for thermal relics and point out the phenomenological possibilities that arise. We discuss variants of dark matter freeze-out within and beyond the paradigm of weakly interacting massive particles (WIMPs) as well as mechanisms for producing non-thermalized dark matter. We furthermore highlight the corresponding experimental probes that allow us to pinpoint the model realized in nature.
