I'd like to be able to tell you that there is a specific way that you should carry yourself while playing. That if you turn a certain way or if you look a certain way, that you'll be in a more protected state. This simply isn't the case. You can be easily flanked or approached from behind and that can be a huge problem for you. The only way to protect yourself in this sport is with the proper gear. You have to consider the fact that these balls full of paint are traveling at speeds up to 200 miles per hour. That is something that is going to hurt when it hits you.
The first thing you're going to need at a minimum is a face mask. This is going to protect your eyes and mouth from getting shot. I say that this is a minimum because you could also get shot in the temples, ears and the back of the head. You can also get a full helmet to help protect your entire head and that's definitely the way I'd go.
Another thing that is nice to have is armor. Basically it looks like a bullet proof vest. It helps to protect the torso area from getting welts all over it. Normally this is the area of your body that is going to receive the most impact, so obviously having armor for it is important.
Lastly, you might want to pick up padded gloves. The reason for this is that if you get shot in the hand, it becomes very difficult to shoot a marker. Basically if you don't want your day ruined, wear gloves.
