Where I come from in SW Ks. most all of us dress in what most would call casual attire. Jeans, T-shirts, etc. I generally wear a tee shirt that is nice with the NRA logo because I am a Benefactor member. It is not tucked in. If I had to play in a tournament I would tuck it in. I think a collared shirt is BS. I wear a hat because it helps cut the glare of the table lights off my glasses. Black Levis and a pair of Rios Mercedes boots. IF that is good enough for funerals and weddings it should pass for a pool tournament. Oh, I do take off the hat in church.