Words for Laws/Rules [法律、規則、規律, etc.]

Question

I feel like there's an endless list of words for laws/rules/regulations and I was wondering what the difference in nuance is between them? Are any of them true synonyms? Here are the ones I know off the top of my head.

法規{ほうき}

法律{ほうりつ}

規律{きりつ}

法則{ほうそく}

規則{きそく}

I know 法則 is more for physical laws like the law of inertia but that's about the only distinction I know.

Answer 1

• 法律: Basically very close to English "law" used in legal contexts. In its narrow sense, it usually refers to statutory laws prescribed under the authority of a legislature. In Japan, only National Diet have the right to create 法律 in the narrow sense. In its broader sense, it may refer to any regulations determined by various government entities, or jurisprudence in general. You can say "I major in 法律 at my university to become a lawyer", for example.
• 法: Has various meanings, but in legal contexts, it's a stiffer way of saying 法律.
• 法規: Regulation; framework of law. Usually a broader idea than 法律, and it includes not only 法律 in its narrow sense but also 条例 (regulation of local government), 制令 (government ordinance), 憲法 (constitution), etc. 法制 is another word which is very close to 法規.
• 規則: Rule. (Written) rules in an company, school, or a similar organizations.
• ルール: Rule. It's a relatively casual word that means the same things as 規則, but ルール also typically refers to rules of sports and games.
• 決まり: Rule. As a 和語, it's a very broad word that sounds more casual and colloquial than 規則. It typically refers to rules within a family, among friends, etc., but in conversations, it can refer to any 法律/法規.
• 掟: An old word which broadly refers to rules, regulations and laws. You will see this only in historical novels and in a few idioms. Maybe "code" is similar.
• 規律: Discipline; organized behavior of people in accord with local laws and rules in a church, a school, an army, etc. It can also refer to a collection of such local rules if used with verbs like 守る and 従う.
• 法則: Laws in the sense of principle or fundamental nature of something. 重力の法則 (law of gravity), マーフィーの法則 (Murphy's law), ムーアの法則 (Moore's law), etc.

Answer 2

I don’t know the difference between 法規 and 法律 very well. My attempt is the following.

I think you can’t drive too fast even if there was no road signs. It is implicitly regulated by the law, which is 法規.

法律 is more of an explicit law. You probably get refund when you buy a PC and it has a defect. The company must agree with a refund policy within 14 days or some intervals. It has to be explicitly written in a receipt.

規律 is close to 規則. It is more of a discipline. Wearing suit for a company or you might be taught “an early bird gets the worm” takes you an ordered life.

法則 is, as you know, used in scientific law. Since we have not seen a time traveler, probably any entity cannot travel faster than light.

規則 is a rule. An institution(ex. school or baseball league) can make a guidelines. Students or baseball players should follow the rule(規則)