One Shot Night is a great opportunity to try out (or introduce people to, if you're a GM) either tabletop RPGs in general or a specific system with short, ~3 hour campaigns. Show up, find a game that interests you, and make some friends!
Unless the GM specifies otherwise, default priority for game spots is based on reverse seniority. In other words, the newer you are to Enigma, the more likely you are to get into the game you want, and if you're a veteran, please give seating priority to new Enigmans. That being said, please remember that all games have limited spots, and sometimes GMs will have to make the difficult choice of turning people away. See you there!