The Anthropic Principle asserts that the Universe we live in must be structured in such a way as to allow for the development of carbon based life forms such as ourselves.
The Anthropic Principle is a profound concept, but not a physical law in the strict sense.
The Anthropic Principle comes in two varieties, the weak and the strong.
The weak form states that the values of certain fundamental constants of the Universe seem selected to allow life to exist only because if our Universe did not have those values, we wouldn't be here to talk about them. The weak form is typically invoked by cosmologists who prefer to answer the question "Why these values?" by asserting that there are probably an infinite number of universes with different fundamental constant values most of which do not support life, but statistically, there will be a small number of universes that do have "life producing fundamental constant values", and ours is one of those universes, because we're here.
The strong form of the Anthropic Principle asserts that the seemingly selected "life allowing" values of fundamental constants for our Universe, understood to be the only Universe, proves that nature, physics, is inherently life selecting. Those who prefer the strong form of the Anthropic Principle fall into two groups: those who believe in intelligent design (God selects life affirming fundamental constant values), and those who think that nature, physics, requires intelligent life. The latter group is inclined to think that Quantum Mechanics requires that there be intelligent life so that reality can exist in the perception of it by intelligent beings. This form of Quantum Mechanics was originally suggested by Eugene Wigner, and later championed by John Wheeler and others.