decision-tables

Build a decision table that maps every meaningful combination of conditions to a specific outcome, and flags the combinations nobody has specified. Use eagerly whenever behavior is governed by combinations of independent yes/no conditions — authorization rules ("if role is admin AND resource is active AND user owns it..."), validation logic with multiple interacting constraints, discount/pricing stacking rules, feature-gating logic, or any business rule the user would naturally sketch as a truth table. Trigger on "what happens when multiple conditions apply", "map out these rules", "decision table", "truth table", "combination of conditions", or "what if a user qualifies for more than one X". If the problem also involves numeric ranges, states, or many independent parameters beyond simple yes/no conditions, the scenario-design skill can help route to the better-fitting technique instead.