Autoimmune encephalitis (AE) encompasses a heterogeneous group of inflammatory brain disorders mediated by pathogenic autoantibodies targeting neuronal cell surface or synaptic proteins. Over the last few decades, the discovery of more than 20 disease-associated and pathogenic antibodies has had a remarkable impact into routine practice. Clinically, AE manifests with a spectrum of symptoms including rapidly progressive cognitive decline, seizures, movement disorders, psychiatric disturbances, and autonomic instability. The pathogenesis involves complex immune mechanisms, often triggered by underlying neoplasms or infections. Diagnosis requires integration of clinical features, cerebrospinal fluid analysis, neuroimaging, and detection of specific neural autoantibodies, with early initiation of immunotherapy proving critical for neurological recovery. Tools such as the Antibody Prevalence in Epilepsy and Encephalopathy (APE2) score have been developed to aid clinicians in identifying patients at higher risk for autoimmune etiologies, guiding the selection of patients for antibody testing and immunotherapy. Understanding the underlying immunopathology, clinical presentation, and diagnostic strategies is essential for preparing to manage these complex and potentially reversible conditions.