It was passed in order to protect "trespassers" in respect of dangers due to the state of the premises or things done or omitted to be done on the premises.
Trespassers can only claim personal injury.
How to prove:
Establish occupier
Occupier owes D.O.C.
Occupier breaches D.O.C. - reasonable steps
Causation - 'but-for'
Direct link between Breach and C's injury
How to establish if the Occupier owes a D.O.C:
Occupier knows of danger
Occupier has reasonable grounds to believe other is in the vicinity/may come in to the vicinity.
The risk is one that the trespasser should be protected against.