We can assume for the purposes of this game that the races can communicate with each other, be it through a common language or some sort of magical translation device.<br/><br/>NO Babelfish! *Glare* That reference stopped being funny after the movie came out.<br/><br/>As for currency. Again, I think that any reasonable group of people would establish some sort of credit system. But I doubt that credit would overstep the local currency. At least not on Fringe Space.<br/><br/>