This text is designed to teach students how to write organic reaction mechanisms. It starts from the absolute basics - counting the numbers of electrons around a simple atom. Then, in small steps, the text progresses to advanced mechanisms. the end, all the major mechanistic routes have been covered. The text is in the form of interactive sections, which are designed to facilitate the assimilation of the information conveyed, so that by the end the student should already know the contents without the need for extensive revision.