Different principles guide how students are selected when there is competition in college admissions. A merit based approach is most common: If there is competition, the candidate with the best qualifications, or merits, "wins." The way merit is defined and measured is a complicated matter that has to do with validity and views of fairness.Systems where desirable positions are promoted based on merit are sometimes called meritocratic, but this term can be interpreted in both positive and negative sense. This chapter describes and discusses principles for allocation of study places where individuals are promoted or selected on the basis of their merits; challenges of such models; and consequences for individuals, higher education institutions, and society at large.