3. Do you know why you know the normal law?

There are an infinite number of probability laws.

For example, if we sum the results of $k$ dice (variable of interest) and we're interested in the distribution of theoretically expected values, it's a matter of "summing up". $k$ discrete uniform laws. This is not a simple operation, and the result is no longer a uniform distribution. However, we can observe the result empirically by running simulations. The support of the variable corresponding to the sum of $k$ dice is the set of integers between $k$...