Ashley Smith’s experience in the adult prison system flowed from certain of its systemic features. This article considers whether and how it is possible to reconcile the basic commitments of sentencing law, including the legal aims of punishment, with that systemic portrait. The youth court that ordered Smith’s transfer to adult custody relied upon an idealized conception of adult imprisonment, just as ordinary adult sentencing courts do. Judges purport to stipulate the severity of punishment, but tend not to consider how prison conditions will shape the severity of the sanction. Even where a particular defendant is likely to face unique difficulties in custody, courts tend to take notice in limited and rare ways. Smith’s experience in adult custody challenges us to more clearly identify, and to consider extending, doctrinal sentencing rules that represent a judicial concern with the effects and prospects of imprisonment in particular cases.