<p>Proponents of the Many Worlds Interpretation (MWI) of quantum mechanics are divided in their attitudes to the idea of quantum immortality. Some, e.g. Max Tegmark (immortalists), believe one should always expect to experience subjective survival in a quantum suicide thought experiment, because one can only ever be on a branch of the universal wavefunction where one is alive. Others, e.g. Sean Carroll, David Papineau and David Wallace (mortalists), believe that the truth of the MWI has no such consequences and that our situation is analogous to that of an observer in a single, non-branching, stochastically-evolving universe. A related question concerns whether we can take survival of a quantum suicide experiment as evidence confirming the MWI. This paper focuses on the core principles underlying these debates by considering each of these questions in turn for idealised cases of quantum immortality, arguing that while rejecting such applications of the idea of quantum immortality is tenable, to do so requires Everettians to pay various methodological and metaphysical costs that are in tension with the particular strand of austere Everettianism exemplified by Carroll, Papineau and Wallace in particular.</p>