When can a person sue for damages?

Question

To my understanding someone can only sue for damages when they can prove that someone (the defendant) caused the damages. Does this mean if someone is in breach of a contract, the other party needs to let damage happen before they can do anything about it?

One simple example would be how when renting a home the landlord shouldn't let themselves in without reason/notice. But if the landlord does this it is unlikely to cause damages so what remedies are available?

Another would be noise pollution. If your neighbor is making a lot of noise, can you do anything about it before you can prove it has caused some grievance like being late for work and getting fired due to lost sleep?

Another way to phrase the question is when can someone be sued when there are no damages?

Answer 1

if someone is in breach of a contract, the other party needs to let damage happen before they can do anything about it?

No. The prospective plaintiff usually has a duty to make a reasonable effort to mitigate damages instead of letting them accumulate. In that case, the defendant would have to reimburse the expenses that mitigation caused, which would still be better than having to compensate for unmitigated losses.

Even if damages have not materialized, a party may seek declaratory relief whereby each parties' rights and duties are judicially determined for when a foreseeable or impending loss occurs.

Each state's legislation might provide remedies for scenarios such as "landlord's unannounced entry in a property", but otherwise the alleged/foreseeable damage shall be reasonably susceptible to compensation. Otherwise, it would be determined that the lawsuit has "no cause of action for which damages the plaintiff can recover".

Answer 2

Breach of a contract entitles the non-breaching party to at least nominal damages (e.g. $1 and court costs). If there is a fee shifting provision, nominal damages are sufficient win an award of attorneys' fees as well and some contracts have liquidated damages provisions setting a dollar amount on hard to value matters like delay in performing a contract.

Many torts (e.g. nuisance) can justify non-economic damages (e.g. for annoyance and disturbing your peaceful quiet). Other torts, such as battery or trespass, entitle a prevailing party to at least nominal damages. On the other hand, there are torts where neither non-economic damages nor nominal damages are usually allowed (e.g. claims for negligence causing only economic damage to an entity).

If a violation of a contract or other legal right is imminent and money damages is not an adequate remedy, some can ask that a court enter an injunction prohibiting that conduct and violation of that injunction is contempt of court punishable with fines and/or incarceration.

If there is a bona fide dispute over what a contract or other legal instrument or a law means, a declaratory judgment action can resolved the dispute even if not damage have yet been incurred (federal court declaratory judgment jurisdiction is narrower than in state courts due to the federal constitutional case or controversy requirement that applies to the federal judiciary).