Shoes – normal running shoes. Cleats won’t help – in fact they’ll be worse on your feet and are dangerous for the other participants.
Clothes – lightweight stuff that dries quickly. Even if it’s a cold day, heavy or thick clothing will just retain water and make you colder. You should also bring a change of clothes for after the event so you can enjoy the post party.
Gloves – this one is more debatable. Some people swear by them, others prefer to go glove-less (faster drying). If you go with gloves, be sure to grab tough, thick ones to prevent burns from the ropes and splinters from the walls.
Other important things:
Photo ID – You MUST bring a photo ID. We cannot stress this enough.
Copy of your confirmation email.
A watch – if you care about knowing your time. It’s on you to time yourself.