This is a short article on Laplace's rule of succession. The rule is derived in the context of a ball and urn model. Specifically, there are \(N + 1\) urns and urn \(k\) contains \(k\) red and \(N - k\) blue balls. An urn is chosen at random and then balls are selected at random from that urn. Laplace's rule is an approximation of the probability that the \(n + 1\) ball is red given \(n\) consecutive red balls.