The Philippines legal system may be considered as a unique legal system because it is a blend of civil law (Roman), common law (Anglo-American), Muslim (Islamic) law and indigenous law.
There are two primary sources of the law:
Statutes or Statutory Law
Statutes are defined as the written enactment of the will of the legislative branch of the government rendered authentic by certain prescribed forms or solemnities are more also known as enactment of congress. Generally they consist of two types, the Constitution and legislative enactments.
In the Philippines, statutory law includes constitutions, treaties, statutes proper or legislative enactments, municipal charters, municipal legislation, court rules, administrative rules and orders, legislative rules and presidential issuance.
Jurisprudence or Case Law
Jurisprudence or Case Law is cases decided or written opinion by courts and by persons performing judicial functions. Also included are all rulings in administrative and legislative tribunals such as decisions made by the Presidential or Senate or House Electoral Tribunals. Only decisions of the House of Representatives Electoral Tribunal are printed as House of Representatives Electoral Tribunal Reports, volume 1 (January 28, 1988-October 3, 1990) to present. They will be available electronically at the Supreme Court E-Library.
Classification by Authority
"Authority is that which may be cited in support of an action, theory or hypothesis." Each of the three branches of government, Legislature, Executive and Judiciary, promulgates laws.
The legislature promulgates statutes, namely: Act, Commonwealth Act, Republic Acts, Batas Pambansa. Executive promulgates presidential issuances (Presidential Decrees, Executive Orders, Memorandum Circular, Administrative Orders, Proclamations, etc.), rules and regulations through its various departments, bureaus and agencies. The Judiciary promulgates judicial doctrines embodied in decisions.
Classification by Source
It is important for legal research experts to know the source where the materials were taken. One has to determine whether they came from primary (official) sources or secondary (unofficial sources).
Primary sources are those published by the issuing agency itself or the official repository, the Official Gazette. Thus for Republic Acts and other "laws" or statutes, the primary sources are the Official Gazette published by the National Printing Office and the Laws and Resolutions published by Congress. For Supreme Court decisions, the primary sources are the Philippines Reports, the individually mimeographed Advance Supreme Court decisions and the Official Gazette. Publication of Supreme Court decisions in the Official Gazette is selective. Complete court reports for Supreme Court decisions is the Philippines Reports.
The Secondary Sources are the unofficial sources and generally refer to those commercially published or those that are not published by government agencies or instrumentalities. Vital Legal Documents contains a compilation of Presidential Decrees (1973) to the present Republic Acts, published by Central Book Supply.