Lockdown and active shooter simulations are frequently confused, but they are distinct in both purpose and execution. Since the 1999 Columbine High School shooting in Colorado, schools across the United States have adopted various preparedness drills to enhance safety. As of 2025, 37 out of 50 states require schools to conduct either active shooter or lockdown drills at least once annually. New York mandates lockdown drills multiple times a year, while Texas requires both lockdown and shelter-in-place drills, in addition to allowing active shooter simulations. The confusion often arises because hyperrealistic active shooter simulations—sometimes involving fake blood, mock gunfire, and even nonlethal projectiles like BB guns—can be mistaken for standard lockdown drills. Lockdown drills typically involve locking doors, turning off lights, and remaining out of sight until an all-clear signal. These drills are not exclusive to active shooter scenarios and may be used for other threats, such as wildlife intrusions or nearby law enforcement activity. In contrast, active shooter simulations are specifically designed to mimic the presence of an armed assailant. These drills may involve actors portraying shooters, simulated gunfire, and other intense elements. Some states, like New York and California, have restrictions on high-intensity simulations, while others distinguish clearly between active shooter drills and lockdown procedures. However, many states lack specific guidelines for these simulations, leading to inconsistencies in how they are conducted. Research on the effectiveness of these drills is mixed. While some studies suggest that lockdown drills may help reduce fear and improve preparedness among students, others raise concerns about the psychological impact of active shooter simulations. The National Academies of Sciences, Engineering, and Medicine warned in a 2023 report about the mental and emotional risks of these drills, highlighting the lack of standardization in how they are implemented. Meanwhile, studies have shown that schools with unsecured doors may be more vulnerable during active shooter incidents, supporting the use of lockdown procedures to increase safety. The American Academy of Pediatrics recommends using neutral terms like “lockdown” or “safety drill” to avoid unnecessary fear, but not all schools follow this guidance. The lack of clear standards and terminology makes it difficult to assess the true impact of these drills on student safety and well-being.