Damnum sine injuria

Damnum sine injuria means damage without injury. 'Damnum' is actual loss or harm, whether in money, comfort or health; 'injuria' is the infringement of a legal right. The maxim states that where a person suffers loss but no legal right of his has been violated, he has no cause of action, however great the loss. The law protects rights, not every interest, and a person who exercises his own lawful rights in a lawful manner is not liable for the harm it incidentally causes to others.

The rule is illustrated by settled English authorities that Indian courts and textbooks follow. In the Gloucester Grammar School case (1410), a schoolmaster who set up a rival school and lowered fees was held not liable to the established school for its loss of pupils. In Mogul Steamship Co. v. McGregor, Gow and Co. (1892), shipowners who combined to drive a rival out of trade by lower freight rates, without illegal means, were held not liable. In Bradford Corporation v. Pickles (1895), a landowner who drew off percolating water under his own land was not liable even though his motive was to pressure the corporation, because he violated no right of the plaintiff.

The maxim is the counterpart of injuria sine damno, which means injury without damage. There a legal right is infringed and the claim succeeds even without actual loss, as in Ashby v. White (1703), where a voter wrongfully prevented from voting recovered damages though his candidate won. Torts actionable per se, such as trespass, fall within injuria sine damno. The two maxims together show that the gist of a tort is the violation of a legal right, not loss as such.

Examiners usually test the contrast between the two maxims, ask which maxim a fact pattern of business competition illustrates, and check that malice alone does not turn a lawful act into a tort, as Bradford Corporation v. Pickles shows.