The district court in resolving inheritance cases is based on customary and western law.[4] The legal basis for resolving customary inheritance law disputes is unwritten customary law.

In this case, judges are required to explore and follow as well as understand the legal values and sense of justice that live in society. This is in accordance with Article 5 (1) of Law Number 48 of 2009 concerning Judicial Power, which affirms that judges are obliged to explore, follow, and understand the legal values and the sense of justice that lives in society.. The provisions in this article will become one of the legal bases for judges to find the law based on customary law or customary law.[5]

2. Settlement of Inheritance Disputes through the Religious Court

The Religious Court as one of the actors of judicial power, its authority is explicitly regulated in Article 2 of Law Number 3 of 2006, which affirms that the Religious Court is one of the actors of judicial power for people seeking justice who are Muslims regarding certain cases. As for the duties and the authority of the Court is regulated in Article 49, namely the Religious Court has the duty and authority to examine, adjudicate, and resolve cases at the first level between people who are Muslims in the fields of marriage, inheritance, wills, grants, endowments, zakat, infaq, shadaqah, and sharia economics.

Inheritance between people who are Muslims is the authority of the Religious Court. Regarding this inheritance provision, it is found in Article 49 letter (b), where what is meant by “inheritance” is the determination of who becomes the heir, the determination of inheritance assets, the determination of the share of each heir, and the implementation of the distribution of these inheritance assets, as well as the court's determination upon a person's request regarding the determination of who becomes the heir, the determination of the share of each heir.

As previously described, that in Indonesia in civil law there is still diversity, where there are three legal systems in force, namely Islamic law, customary law and western civil law. These three legal systems also influence inheritance law in Indonesia. Sometimes inheritance causes a polemic and can even lead to disputes. So that the settlement of this inheritance dispute is also colored by the Islamic, customary, and western legal systems.

These three legal systems in force in Indonesia indicate the existence of legal pluralism. According to Werner Menski, legal pluralism (legal pluralism) is an approach in understanding the relationship between state law (positive law), socio-community aspects (sosio-legal approach) and natural law (moral/ethic/religion) or if it can be simply explained, it is the validity of several orders or legal systems (state legal system, customary legal system and religious legal system) that apply simultaneously in the same social field.[6]