What is negligence?
Negligence: A breach of legal duty care which results in the damage to the claimant (Rogers W.V.H 2002 Winfield and Jolowicz on Tort 16th edn, London: Sweet & Maxwell p.103)
To prove negligence, the burden falls on the plaintiff to prove all of:
Claimant owed a duty of care
The damage was not too remote
There was a breach of duty of care.
Claimant suffered damage as a result of the breach (causation)
What then, constitute as legal duty of care?
This concerns the relationship between the plaintiff and the defendant. There must be some sort of obligation for the defendant to take proper care to not cause an injury to the claimant at all times. There are 2 scenarios where one can owe a duty of care to somebody:
Established duty situation: usually have some sort of special relationships between the parties
One road user to another
Employer to employee
Doctor to patient
Manufacturer to consumer
Solicitor to client
Those established by case laws
Major developments of negligence
The Neighbor Principle
Outside of established duties, a duty of care can arise from precedents in case law.
Initially, the "neighbor principle" test was used to determine whether a duty of care actually existed between parties.
Donoghue v Stevenson 
"The rule that you are to love your neighbor becomes in law, you must not injure your neighbor .....you must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your neighborÃ¢ÂÂ¨ Who, then, in law is my neighbor?Ã¢ÂÂ¨Persons who are so closely and directly affected by my act(proximity) that I ought reasonably to have them in contemplation as being so affected... " - Lord Atkin in the Donoghue case judgment
What then, is the neighbor principle?