Prompt templates are a defensive mechanism that structures prompts in a way that clearly separates system instructions from user-provided content. By placing user inputs into predefined variable slots rather than allowing them to influence the prompt structure, prompt templates reduce the risk of prompt injection. This separation is conceptually similar to parameterized SQL queries, which isolate query logic (code) from user-supplied values (data) to mitigate SQL injection attacks. While prompt templates significantly limit an attacker’s ability to manipulate system prompts, they should be combined with additional safeguards for comprehensive protection.