A gaming machine connected in a gaming network or operating as a stand-alone machine, is capable of accepting two or more currencies for wager game play. The machine operates internally using a native monetary type and converts non-monetary bills to native amounts in the form of restricted or cashable credits. The multiple currency capability of the machine is utilized to encourage the use of restricted credits by adjusting conversion rates, payback tables, and the like. These features, combined with the use of restricted credits, also enable ways to monitor abuse and illegal activity on the gaming machine and implement ways to limit losses by a player. Certain post-conversion processes are used to ensure that the player is returned non-converted amounts. The gaming machine has additional hard and soft meters to process multiple monetary types.