In a reaction (at equilibrium) that makes more moles of gas than it consumes, what is the effect of increasing the pressure?

Shifts the equilibrium to side that has fewest moles of gas.

Explanation:

"Le Chatelier's principle", also called as the equilibrium law in chemistry explains the effect in different states on some chemical equilibria. It states that when a system is in equilibrium for a long time, it is subject to change in pressure, volume, temperature or condensation.

In this case, with an "increase" in pressure, there would be a shift to the side of fewer moles of gas. Mainly the change towards the reactants.