England's new School Admissions Code endorses the use of lotteries to admit students to oversubscribed schools. Is this endorsement wise? This article argues that lotteries make decision-making without regard to reasons possible. This sanitizing effect is desirable in order to protect against bad reasons. This effect could make at least four distinct contributions to school admission arrangements. The most important of these contributions is the ability of lotteries to ensure "impartiality", an essential component of justice. Whether these contributions justify resort to admission by lottery, however, depends upon the circumstances under which admission must take place, and these circumstances are likely to be controversial in real-life cases. (Contains 22 notes.)