Inheritance law plays an important role in ensuring legal certainty in the transfer of rights over an estate while simultaneously protecting the interests of heirs. In practice, a will serves as an instrument that enables a person to determine the disposition of their property after death. Problems arise when testamentary freedom potentially reduces or even eliminates the legally protected reserved portion belonging to certain heirs. This situation creates tension between the principle of testamentary freedom and the principle of protecting heirs’ rights. This study employs a normative juridical method using statutory and conceptual approaches. It argues that testamentary freedom cannot be regarded as an absolute right but must be understood within the framework of legal protection for the legitieme portie as a limitation on the testator’s individual autonomy. The findings show that a will retains legal standing as an expression of the testator’s final wishes, but its enforceability is limited when its provisions diminish the protected reserved portion of the heirs. In such circumstances, disadvantaged heirs have a legal basis to seek reduction (inkorting) of testamentary dispositions that exceed the portion lawfully available for disposition. These findings demonstrate that inheritance law places wills and legitieme portie in a mutually limiting relationship, thereby recognizing testamentary freedom without eliminating the protection of heirs’ reserved rights. Accordingly, the protection of legitieme portie reflects an effort to maintain a balance between the testator’s autonomy and fairness for heirs within the system of civil inheritance law.