The game begins with the creation of your Commander Shepard. You're free to go with the model that has been used in all of the marketing, or you can make your own; male or female and with a variety of background and visual options. The decisions you make here have a substantial bearing on the game itself. Some people you meet in the game will deliver different dialogue if you're playing as a woman. Which background options you choose for your character will also shape the way people talk to you throughout the course of the game. The most important decision you'll make will be which character class to start with.