This systematic literature review surveys technical defenses against software-based cheating in online multiplayer games. Categorizing existing approach-es into server-side detection, client-side anti-tamper, kernel-level anti-cheat drivers, and hardware-assisted TEEs. Each category is evaluated in terms of detection effectiveness, perfor-mance overhead, privacy im-pact, and scalability. The analy-sis highlights key trade-offs, particularly between the high visibility of kernel-level solutions and their privacy and stability risks, versus the low intrusive-ness but limited insight of server-side methods. Overall, the re-view emphasizes the ongoing arms race with cheaters and the need for robust, adversary-resistant anti-cheat designs.