The knowledge-based rational decision model (KBR-model) offers an approach to rational decision making in a non-probabilistic setting, e.g., in perfect information games with deterministic payoffs. The KBR-model is an epistemically explicit form of standard game-theoretical assumptions, e.g., Harsanyi’s Maximin Postulate. This model suggests following maximin strategy over all scenarios which the agent considers possible to the best of his knowledge. In this paper, we compare KBR with other approaches and show that KBR is the only non-probabilistic decision-making method which is definitive, rational, and based exclusively on knowledge.