| It's the|
The common law is a body of English and Welsh (and later Commonwealth and U.S., save for Louisiana, Quebec, and to a degree South Africa) legal precedents separate from written laws, such as statutes (enacted by a legislature), regulations (promulgated by executive agencies), and written constitutions. The common law itself is subdivided into two "types" of law, one called, er, common law, and the other one called equity; the distinction is mostly only important to lawyers and people involved in lawsuits, since the main difference between them is that the one is what you have to do to get money damages (or, very technically, punish someone for committing a crime), and the other is what you have to do to get a court order for someone to do something/not do something. The term "common law" may also be used to refer to the body of judicial practice built around a statute (or Constitution) — that is, instances where the interpretation of a statute has forced courts to make a judgment as to what the law ought to be without guidance from the legislature (these are particularly common in American income tax law, which leaves a lot of gaps) that has become law as a precedent.
Crucial to the development of common law is the principle of stare decisis, under which the decision in a case before the court is resolved based on prior judicial decisions. A good deal of American and British law remains common law, rather than legislative law, and is based mostly on judicial guidance. Common law is contrasted with civil law, the legal system most common outside the anglophone sphere, which is based entirely (rather than partially) on statutory law, especially the code Napoléon or Napoleonic Code.
The common law and lawquackery
|—The Anti-Defamation League|
To a certain strain of irrational thinker, however, especially American and often espousing extreme right-anarchist, racist, or fascist viewpoints, "common law" represents a semi-mythical body of legal theory that represents a type of idealized state free of judicial activism; in practice, the end result is generally believed to be some kind of quasi-anarchic state with very few fetters (e.g. taxes or regulations) on the individual. Manifestations of such thinking include the militia movement and often-connected extrajudicial courts, unrecognized by any governmental authority, which invoke this concept of common law to file charges and bring legal decisions against governmental authority. Many of the "common law" advocates in the United States are disaffected rural white males, usually fundamentalist Christian in their belief, and distrustful of government due to perceived intrusions on local lifestyles.
“”Militia and common law court propagandists on the Internet have openly expressed sympathy for 'patriot' activists on trial for committing, or planning to commit, acts of violence.
|—The Anti-Defamation League|
Some tax protestors claim that the only reason we've been duped into paying income taxes is that we have allowed ourselves to be entangled in "statutory law", and that it's possible to opt out of every statute in the land — including those statutes that impose taxes — and be subject only to the Common Law. As you can see from the fact that there is "common law" based on statutes and that there is even a "common law" respecting the very same federal income tax they're trying to get out of, this makes no sense, and the protestors' claims to be outside the jurisdiction of statutory law hold up in court every bit as well as their other pseudolegal arguments.
The concept of attorney-client privilege, that communications between an attorney and the attorney's client is secretive protected from court intrusion grew out of English common law, and is not codified. There is a mythology among some non-lawyers that this is an absolute — it is not. The privilege is strictly for legal advice, and does not apply to "business, lobbying, or public relations advice". It also does not apply when the attorney and client are both engaged in crime, tort, or fraud. This myth was part of the TV series Breaking Bad, and was also used by Sean Hannity ("I might have handed him 10 bucks [and said,] 'I definitely want your attorney-client privilege on this.' Something like that.").
- Militias and 'Common Law Courts': 'Patriots' of the Web (2001): http://archive.adl.org/poisoning_web/militias.html
- Constitutionalism: The White Man's Ghost Dance
- Sean Hannity’s idea of 'attorney-client privilege' was right out of 'Breaking Bad' by Kyle Swenson (April 17 at 3:13 AM) The Washington Post.
- See the Wikipedia article on Attorney-client privilege.
- Recap / Breaking Bad S 2 E 8 Better Call Saul TV Tropes.