It may seem strange to have rules in the jungle. After all, the expression "the law of the jungle" has come to be synonymous with people being able to do what they want, whenever they want. But, as Mowgli learns from growing up in a wolf pack, there are indeed a number of rules in operation in the jungle to make sure that all the many animals who live there can do so without too much animosity. They are as follows:

• The strength of the wolf lies in the pack, and the strength of the pack in the wolf. This means that all members of a pack must work together for the common good.
• Wash daily, drink deeply, but not too deep. The night is for hunting, the day is for sleeping.
• A jackal may follow a tiger to find food (i.e., scavenge some scraps), but once a wolf is fully grown and has all his whiskers, he must get his own food.
• Keep the peace with the lords of the jungle, such as the tiger, the panther, and the bear. Also make sure not to mock Hathi the Silent—a large Indian elephant—or the boar in his lair.
• If your pack should meet another pack in the jungle, lie down and wait until the leaders of each pack have spoken. This is a way of preventing fights breaking out between rival wolf packs.
• If a fight should break out with a wolf from another pack, you must fight him yourself well away from the other pack members. This is to ensure that a full-scale war doesn't break out, which would diminish the size of the pack.

Mowgli learns the Law of the Jungle from Baloo, who knows all of the laws and teaches them to Mowgli, at least in part because Mowgli is an eager student, whereas the wolves typically learn only the rules that apply the most to them. Laws are mentioned or defined occasionally, such as not killing anyone at a watering hole when a "water truce" is declared. Fear is implied to be the only "law" that applies equally to all animals.

In "The Law of the Jungle", a number of rules are laid out, although we are told that there are "hundreds and hundreds" more, plus these are only the rules that are followed by or pertain to wolves. 

Most of the laws are guidelines for living, and how one is meant to interact with other wolves and other animals so as to minimize conflict. A few of the laws do provide a sort of overall authority; for example, the word of the Head Wolf is law in all judgments that are not immediately obvious, and the "haunch and the hump" of the law, i.e. its core, is to obey. Most emphatically, the law states that one must never kill man, i.e. a human.