Payment of the Royalty. Licensee assumes all risks associated with fluctuations in foreign currency exchange rates. Licensee shall pay and agrees to pay all sums due Id Software in United States Dollars. With respect to Royalties used for commercial use outside the United States, other currencies shall be exchanged at the Expense of Licensee into United States Dollars using the bid price quoted at the Citibank, N.A. of New York, New York, for the purchase of United States Dollars at the close of business on the last day of the calendar quarter during which any amounts accrue. Payment of the Royalties shall be made in Dallas County, Texas.