The hardest campus to get into within the California State University system is California Polytechnic State University, San Luis Obispo. While most CSU campuses maintain high or moderate acceptance rates, Cal Poly San Luis Obispo typically features an acceptance rate hovering around 30 percent. This heightened selectivity stems from its immense popularity, prestigious reputation for technical education, and a rigorous, major-specific admissions process that requires applicants to meet extremely competitive criteria, especially within impacted disciplines like engineering, architecture, and computer science.