  We summarise a recent reconstruction of the quantum theory of qubits from
rules constraining an observer's acquisition of information about physical
systems. This review of [arXiv:1412.8323, arXiv:1511.01130] is accessible and
fairly self-contained, focussing on the main ideas and results and not the
technical details. The reconstruction offers an informational explanation for
the architecture of the theory and specifically for its correlation structure.
In particular, it explains entanglement, monogamy and non-locality compellingly
from limited accessible information and complementarity. As a byproduct, it
also unravels new `conserved informational charges' from complementarity
relations that characterise the unitary group and the set of pure states.
