  The study of CP violation in $B$-meson decays has already reached a high
level of precision, which will be pushed even higher in the future era of
Belle-II and the LHCb upgrade. %Important probes of CP violation are the
$B_d^0$ and $B_s^0$ mixing phases and the CKM angle $\gamma$. Here, the
theoretical challenge is to control the uncertainties from strong interactions
to distinguish between the Standard Model and possible New Physics effects. In
this talk, I will present a selected overview of recent theoretical
developments in this field. This includes, in particular, the semileptonic
asymmetry $a_{\text{sl}}^s$ and extractions of the CKM angle $\gamma$ and the
$B_d^0$ and $B_s^0$ mixing phases. I focus on recently proposed strategies in
which the theory uncertainties can be controlled through data using flavour
symmetries of the strong interaction. A newly found puzzle in the $B \to \pi K$
system is highlighted and a theoretically clean way to determine the underlying
electroweak penguin parameters is discussed. Finally, the recent progress to
describe three-body $B$ decays in QCD factorization is discussed.
