This chapter introduces key randomization techniques used in clinical trials to ensure unbiased allocation of participants and enhance the validity of study results. It begins with the concept of random allocation and its role in eliminating selection bias. Different approaches are then explored, including systematic allocation, simple random allocation, blocked random allocation, stratified random allocation, and cluster random allocation. For each method, the principles, procedures, advantages, and potential limitations are discussed, providing researchers with the knowledge to select the most appropriate randomization strategy for their trial design.