This book theorises and concretises the idea of absolute rights in human rights law with a focus on Article 3 of the European Convention on Human Rights (ECHR). It unpacks how we might understand what an absolute right in human rights law is and draws out how such a rights delimitation may remain faithful to its absolute character. Concretising these starting points, it considers how, as a matter of principle, the right not to be subjected to torture or inhuman or degrading treatment or punishment enshrined in Article 3 ECHR is and ought to be substantively delimited by the European Court of Human Rights (ECtHR). Focusing on the wrongs at issue, this analysis touches both on the core of the right and on what some might consider to lie at the rights fringes: from the aggravated wrong of torture, to the severity assessment delineating inhumanity and degradation; the justified use of force and its implications for absoluteness; the delimitation of positive obligations to protect from ill-treatment; and the duty not to expel persons to places where they face a real risk of torture, inhumanity or degradation.