r/PromptEngineering: Players in Public Adversarial AI Game Independently Discover the Same Prompt Injection Attacks — Developer Says Convergence Signals a Bounded, Structural Threat Class

A developer running a public prompt-injection adversarial game logged approximately 6,700 attacks over one month and found that independent players with no coordination consistently converged on the same five or six effective attack strategies. The convergence suggests prompt-injection attack space has discoverable structural properties—patterns skilled attackers naturally rediscover rather than invent—which the developer argues changes how defenders should prioritize hardening. If attacks are structurally predictable rather than open-ended, targeted mitigations for the known convergence points should be more effective than broad or randomized defenses.