Richard Rumelt's book 'Good Strategy Bad Strategy' differentiates between effective and ineffective strategies, emphasizing the importance of clear diagnoses, guiding policies, and coherent actions. A good strategy identifies key challenges and articulates a plan to overcome them, while a bad strategy confuses ambitions and goals with actual strategy, leading to incoherence and ineffective outcomes. Rumelt also highlights the pitfalls of bad strategies, including vague objectives and a lack of real choice in decision-making.