In complex situations with risks of critical irreversibility, decisionmakers must be able to take action quickly but also appropriately, especially in response to unexpected events. In these situations, “the first error in the trial-and-error-learning will also be the last trial” (Weick & Sutcliffe, 2011: 20). This paper assesses the contribution of the meta rule concept, defined as the conditions to respect to maintain the integrity of the organization in an unexpected situation. Our design tests the relevance of two conceptual approaches: high reliability organizations (HRO) and sensemaking approaches. The main proposal of this research is to highlight that, for a decision-maker, understanding a situation through meta rules at key times limits the risk of information overload by facilitating an overall understanding of the situation. It becomes possible to make decisions quickly, if necessary, using new robust and reliable strategies. Using a quantitative study of the behaviors of a warship bridge team composed of cadets in the French Naval Academy, the authors tested various situations that young officers have to manage. The results highlighted that meta rules play a positive mediating effect between rules and reliability and between interactions and reliability. With the use of meta rules, the overall reliability level is higher when employing an HRO approach than when using a sensemaking approach.