Many researchers encounter nonequilibrium phenomena in their studies of order in seemingly chaotic systems. One promising approach to understanding nonequilibrium phenomena is by using lattice gas models which consider complex systems as collections of simple elements each related by simple rules. This book, by leading researchers in the field, presents an up to date and accessible account of this fascinating subject and includes many references. It will be of interest to statistical physicists and to researchers in areas including mathematics, chemistry, mathematical biology and geology interested in complex systems.