How can pressure affect the equilibrium shift of a reversible gaseous reaction?

Le Chatelier's Principle states the if a change is applied to a system in equilibrium, then the position of equilibrium will move to counteract that change. So, if the pressure was increased for a reaction the equilibrium would shift to decrease the pressure and hence favour the side of the reaction with less gaseous molecules. If the pressure was decreased the equilibrium would shift to increase the pressure and hence favour the side of the reaction with more gaseous molecules.