The problem before the rule
Is this one wrong, or several different legal claims arising from the same act?
A paid courier deliberately keeps a customer's parcel and sells it.
Reveal the legal analysis
The conduct may breach the delivery contract, amount to conversion in tort and attract criminal liability. Each claim has its own ingredients and remedies.
Classify every legal relationship instead of choosing only one label.The shortest useful answer
The same conduct may create several liabilities, but each field asks a different question and protects a different legal interest.
- Distinguish tort from contract and quasi-contract.
- Separate civil liability from criminal responsibility.
- Recognize overlap without merging legal tests.
Doctrine 01
The controlling distinctions
Focus on where the duty comes from and what the proceeding seeks to achieve.
- Tort
- Duty is primarily fixed by law. The claimant seeks compensation or protection for violation of a legally protected interest.
- Contract
- Duty primarily arises from voluntary agreement. The remedy protects the promised performance interest, subject to contract rules.
- Quasi-contract
- Liability is imposed by law to reverse unjust enrichment even though the parties made no true contract.
- Crime
- A public prosecution addresses conduct treated as an offence against society, with punishment and statutory procedure at its centre.
Doctrine 02
When liabilities overlap
One set of facts may satisfy more than one legal cause of action.
- Professional services
- Careless medical or professional work may breach both contractual terms and an independent duty of care.
- Violence or fraud
- Assault, dishonest conversion or fraud may create tort damages and criminal prosecution.
- Public authority
- State misconduct may produce private tort, statutory and constitutional remedies.
- Separate proof
- The claimant or prosecution must establish the ingredients, limitation and standard of proof belonging to each route.
Read the judgment like a lawyer
The cases that move the rule
A citation is useful only when you can explain what changed after the court spoke.
Core authority
Donoghue v. Stevenson
[1932] AC 562
- Facts that matter
- A friend bought Donoghue a sealed bottle of ginger beer. After part of it was consumed, a decomposed snail was found inside. Donoghue had no contract with the manufacturer.
- The legal question
- Can a manufacturer owe a duty of care to the ultimate consumer despite the absence of contractual privity?
- The holding
- A duty of care can arise independently of a contract between the claimant and defendant.
- Why the court got there
- The product was intended to reach the consumer without a reasonable chance of intermediate examination. Foreseeability and closeness of relationship justified a direct duty of care.
- Where it earns its place
- Use it to show why absence of contractual privity does not necessarily defeat a tort claim.
Development authority
State of West Bengal v. B.K. Mondal & Sons
AIR 1962 SC 779
- Facts that matter
- A contractor completed construction requested by government officers, but the formal agreement was unenforceable. The State nevertheless used and enjoyed the work.
- The legal question
- Can payment be required without a valid contract when a lawful, non-gratuitous benefit has been accepted?
- The holding
- A lawful non-gratuitous benefit accepted by another may create a restitutionary obligation despite absence of an enforceable contract.
- Why the court got there
- Restitution prevents the recipient from retaining an accepted benefit without paying reasonable value. The obligation comes from law, not an implied promise.
- Where it earns its place
- Use it to distinguish quasi-contractual restitution from compensation for a civil wrong.
Write it under pressure
A clean answer sequence
- 01
Identify the source and beneficiary of each duty.
- 02
Compare the protected interest and legal ingredients.
- 03
State the remedy and applicable standard of proof.
- 04
Explain any overlap without combining distinct tests.
The 60-second recall
Close the page only when these feel obvious
- 01Tort duty is fixed by law.
- 02Contract duty is voluntarily assumed.
- 03Quasi-contract reverses unjust enrichment.
- 04Crime is prosecuted as a public wrong.
- 05One act may create multiple liabilities.
What is the source of duty in each field?
Why is quasi-contract not a true contract?
Can negligence be both tort and contract?
Questions students actually ask
Clear the last two doubts
Can the same act be both tort and crime?
Yes. Assault, fraud and property interference can support civil compensation as well as criminal prosecution.
Is quasi-contract based on consent?
No. The law imposes restitution to prevent unjust enrichment despite the absence of a true agreement.