Runners are responsible for their own safety and kit whilst out running on a trail race. What you take with you depends on what distance you are running, but we would advise taking / wearing the following at a minimum:
Trail shoes with a decent tread
A running rucksack / bag
Your race number given to you at registration
A spare layer, and a waterproof jacket (weather dependent)
At least 1 litre of water in refillable bottles / soft flasks so you can fill them up in the aid stations.
Enough food for the duration you will be out. There are aid stations on the longer routes, but you should always carry your own personal food
A mobile phone
A first aid kit