*Abstract:* Does pure chance exist? Apart from philosophical speculation, the only reliable answer to this question comes from two theorems about quantum physics:Bell's Theorem from 1964 and the so-called Free Will Theorem of Conway and Kochen from 2008. We give a (new) mathematically sound reformulation of the first, as well as a comprehensible version of the second, and discuss their mutual relationship. No prior knowledge of physics is required (except some everyday experience with light), and mathematical preliminaries are limited to elementary probability theory and linear algebra.