Tortious interference protects economic relationships from wrongful disruption by outsiders. It comes in two related forms: interference with an existing contract, and interference with a prospective (expected but not yet contracted) business relationship. In both, a third party -- not a party to the relationship -- is alleged to have wrongfully caused its breach or failure.

The doctrine sits at a tension point: the law protects contracts and business expectancies, but it also protects legitimate competition. Not every act that costs someone a deal is tortious. The dividing line is whether the defendant's interference was improper or wrongful, not merely effective.

Interference with an existing contract generally requires: (1) a valid contract between the plaintiff and a third party; (2) the defendant's knowledge of it; (3) intentional and improper acts inducing or causing a breach or disruption; (4) actual breach or disruption; and (5) resulting damages.

Interference with prospective economic advantage is similar but concerns a relationship that has not yet ripened into a contract. Because there is no existing contract, courts usually demand a stronger showing of wrongful conduct -- often independently wrongful means such as fraud, defamation, or unlawful acts -- to distinguish it from lawful competition.

The pivotal question is whether the interference was improper. Courts weigh factors such as the defendant's motive, the nature of the conduct, the interests of the parties, and the social interest in protecting both contractual security and free competition. Persuasion through legitimate means, or pursuing one's own legitimate business interest, is often privileged.

This is why competitors, and parties with a financial or contractual interest of their own, frequently invoke privilege or justification defenses. Interference driven by a legitimate competitive or economic interest, pursued by lawful means, is generally not actionable.

Plaintiffs prove the relationship or expectancy, the defendant's knowledge of it, intentional acts aimed at disrupting it, causation of the breach or lost expectancy, and damages. Evidence of the defendant's improper motive or wrongful means is often decisive.

Defendants deny knowledge or intent, argue the plaintiff had no valid contract or reasonable expectancy, contest causation (the deal would have failed anyway), or assert privilege and justification -- fair competition, protecting one's own contractual or financial interest, or giving truthful information or honest advice. Truth is generally a defense where the interference rests on statements.

Tortious interference is a favored theory in commercial and competition disputes because it reaches a third party who engineered a breach the contracting party itself might be unable or unwilling to pursue. The privilege and 'improper' inquiries make it fact-intensive and often unsuited to early dismissal.

As a claim path, the elements form liability nodes and the improper-conduct and privilege questions form a contested branch that can defeat the claim even when interference clearly occurred. In Juricratic you can war-game the case by dialing the defendant's motive, the wrongfulness of the means, and the strength of any competition privilege, then watch how the modeled path to liability shifts. The dials are hypothetical, not predictive.