The kinetics of coke formation in the catalytic cracking of vacuum gas oil are expressed in terms of elementary steps of carbocation chemistry, along the lines used for the main reactions of this process. The reaction network is generated by a computer, without any lumping of components and elementary steps. The rate coefficients depend on the type of elementary step and the nature of the reacting and produced carbocations or molecules, but the single-event concept accounts for the other structural aspects. The application of this concept, a number of plausible assumptions, and thermodynamic constraints tremendously reduce the number of rate parameters to be determined from experimental data. The effect of coke deposition on the activity of the catalyst is accounted for by means of deactivation functions written in terms of the coke content of the catalyst, not contact time. The kinetic model is applied in the simulation of a commercial riser reactor for the catalytic cracking of three types of vacuum gas oil. The results are presented in terms of the usual commercial fractions but also in terms of more detailed fractions, which provide further insight in the process and the catalyst deactivation.