Nemo judex in causa sua

Volenti non fit iniuria (or injuria) 

Volenti non fit iniuria (or injuria) (Latin: "to a willing person, injury is not done") is a common law doctrine which states that if someone willingly places themselves in a position where harm might result, knowing that some degree of harm might result, they are not able to bring a claim against the other party in tort or delict. Volenti applies only to the risk which a reasonable person would consider them as having assumed by their actions; thus a boxer consents to being hit, and to the injuries that might be expected from being hit, but does not consent to (for example) his opponent striking him with an iron bar, or punching him outside the usual terms of boxing. Volenti is also known as a "voluntary assumption of risk."

Damnum Sine Injuria

It means damage which is not coupled with an unauthorized interference with the plaintiff’s lawful right. Causing of damage, however substantial, to another person is not actionable in law unless there is also the violation of a legal right of the plaintiff.

In Gloucester Grammar School case, the defendant had set-up a rival school to that of the plaintiffs with the result that the plaintiffs were required to reduce the tuition fees of their school substantially. It was held that the plaintiff had no cause of action against the defendant on the ground that bonafide competition can afford no ground of action, whatever damage it may cause.

Injuria Sine Damno

Injuria sine damno means the violation of a legal right without causing any harm, loss or damage to the plaintiff. It is just reverse to the maxim damnum sine injuria. In Ashby v. White, (1703) 2 LR 938, the plaintiff was a qualified voter at a parliamentary election, but the defendant, a returning officer wrongfully refused to take plaintiff’s vote. No loss was suffered by such refusal because the candidate for whom he wanted to vote won in spite of that. The defendant was held liable, even though his actions did not cause any damage.