The recent economic crises that Brazil has experienced in the last two years - such as the Covid-19 pandemic and the war between Russia and Ukraine - have generated numerous disruptions in the fulfillment of contracts, and, consequently, the imbalance of its benefits. The implementation of the continuous or deferred execution s contract and its effects in time generate, by itself, a range of risks that need to be managed effectively. The present study aims to analyze the limits of the juristic act of the ex lege protection of the contractual balance provided for in articles 317 and 478 to 480 of the Brazilian Civil Code, widely negotiated between parity parties and, in which contractors establishes its own criteria for the configuration of excessive burden, modifying, restricting or excluding the ex lege protection of the contractual balance, and removing, definitively or provisionally, the revisional and/or the resolutive actions provided in the aforementioned provisions. Such analysis is relevant, since the national civil legislation did not state, nor provided any indication as to the nature of those rules.