Conversion is the tort equivalent of civil theft: it imposes liability on someone who so substantially interferes with another's personal property that the law requires them to pay its full value, as if they had bought it. It protects personal property (chattels), not real estate, and it is distinguished from lesser interferences — like trespass to chattels — by the seriousness of the interference. A minor, temporary meddling with someone's property is trespass to chattels; taking it, destroying it, selling it, or refusing to return it altogether is conversion.

Conversion does not require the defendant to have intended to steal or to know the property belonged to someone else — good-faith mistake is generally not a defense, which makes conversion a strict-in-practice claim once the elements are shown, unlike many intentional torts that turn heavily on the defendant's state of mind toward the plaintiff specifically.

A plaintiff generally must show: (1) the plaintiff owned, possessed, or had an immediate right to possess the personal property, (2) the defendant intentionally exercised dominion or control over that property, and (3) the exercise of control was so serious an interference with the plaintiff's rights that it justifies requiring the defendant to pay the property's full value, rather than merely compensating for the diminished use.

The 'intent' required is only the intent to exercise control over the property (or the intent to do the act that constitutes control) — not an intent to interfere with the plaintiff's rights or knowledge that the property belonged to someone else. Someone who buys stolen goods in good faith, or who mistakenly takes property believing it is their own, can still be liable for conversion even though they did nothing morally blameworthy toward the true owner.

Courts commonly look to factors drawn from the Restatement: the extent and duration of the control exercised, the defendant's intent to assert a right inconsistent with the plaintiff's rights, the defendant's good or bad faith, the harm done to the property, and the inconvenience and expense caused to the plaintiff. Selling, destroying, substantially altering, or permanently withholding property despite demand for its return are classic conversion fact patterns. A brief, non-damaging interference, or a refusal to return property for a short and reasonable period while verifying ownership, more often sounds in trespass to chattels than conversion.

A refusal to return property upon a proper demand is frequently treated as strong evidence of conversion even where the initial taking was innocent, because the refusal itself is the act asserting dominion inconsistent with the owner's rights.

Conversion traditionally applies to tangible personal property, and courts have extended it to intangible property that is merged into, or represented by, a document — a stock certificate, a promissory note, a deed. Ordinary claims for money owed under a contract are generally not conversion, because a debt is not specific identifiable property; but conversion can apply to a specific, identifiable fund or a specific, segregated sum of money the defendant was obligated to keep separate and instead misappropriated, which is a frequent fact pattern in disputes over escrow funds, trust accounts, and commingled client or partnership funds.

Remedies typically include the fair market value of the property at the time of conversion, sometimes plus interest and consequential damages, or in some jurisdictions the plaintiff may elect to recover the specific property itself (replevin) rather than its value.

In Juricratic, conversion is modeled with the seriousness-of-interference determination as the key discretionary node separating it from a lesser trespass-to-chattels theory. You set a dial for the plaintiff's possessory or ownership interest, a dial for the strength of the evidence that the defendant exercised dominion inconsistent with that interest (sale, destruction, refusal on demand), and a severity dial reflecting the Restatement factors that push the interference from trivial to conversion-level serious. Because good faith is not a defense to the underlying claim but does affect damages and equitable considerations in some jurisdictions, the simulation separately tracks how the defendant's intent dial moves remedy exposure without moving liability itself.