Abstract : This volume contains the proceedings of the 18th International workshop AUTOMATA and the 3rd international symposium JAC.
AUTOMATA workshop series aims at gathering researchers from all over the world working in fundamental aspects of cellular automata and related discrete complex systems. Topics cover (although they are not limited to): dynamics, topological, ergodic and algebraic aspects, algorithmic and complexity issues, emergent properties, formal language processing, symbolic dynamics, models of parallelism and distributed systems, phenomenological descriptions, scientific modeling and practical applications. JAC (Journ\'ees Automates Cellulaires) is a bi-annual symposium covering the same topics and was created to have a very high standard international conference in the domain. This one will be the third event of the series after Uzès (2008, France), Turku (2010, Finland).