Abuse of process targets misuse of the machinery of the legal system itself — a subpoena, an attachment, a lien, a criminal complaint, or the litigation process generally — after it has been properly issued, when it is used to accomplish some ulterior purpose the process was never designed to achieve. Unlike malicious prosecution, it does not require that the underlying proceeding lacked probable cause or that it ended favorably to the plaintiff; the proceeding itself can be entirely proper and even successful. What makes it actionable is the improper use to which validly obtained process is put.

A useful shorthand: malicious prosecution is about wrongfully starting a proceeding; abuse of process is about wrongfully using a proceeding, or a piece of process within it, once it exists — for example, using a lawful subpoena to harass a business competitor's customers rather than to gather evidence, or using an arrest for an unrelated business dispute to coerce payment of a debt that has nothing to do with the charge.

A plaintiff generally must show: (1) the defendant used a legal process (civil or criminal) against the plaintiff, (2) the defendant had an ulterior motive or improper purpose in using it — one not proper under the process's own purpose, and (3) the defendant committed a willful act in the use of that process not proper in the regular conduct of the proceeding, sometimes described as a use of process for a purpose for which it was not designed. Many jurisdictions also require the plaintiff to show resulting damage.

Some formulations collapse this into two elements — an ulterior purpose and a willful act in the use of process not proper in the regular course of the proceeding — but the substance is the same across the variations: proper process, put to an improper collateral use.

The classic fact pattern is using process as leverage to obtain something the process itself has nothing to do with — filing or threatening criminal charges to collect an unrelated civil debt, using discovery subpoenas to harass or intimidate a party's business relationships rather than to gather relevant evidence, or attaching property with no genuine intent to pursue the underlying claim but solely to pressure a settlement or tie up assets. The touchstone is that the process was used to obtain a collateral advantage outside the legitimate scope of the proceeding, not merely that the defendant also wanted a favorable outcome from a proceeding that was itself proper.

Merely having a bad or vindictive motive for bringing an otherwise proper lawsuit is generally not enough by itself; there must be a further, willful act using the process for a purpose it was not intended to accomplish. Filing a lawsuit with the hope of embarrassing an opponent, without more, is typically not abuse of process if the process is otherwise used in its regular, intended manner.

Abuse of process does not require that the underlying proceeding lack probable cause, and it does not require favorable termination of that proceeding — a claim can arise even while the underlying case is still pending, or even if the underlying case was meritorious and the defendant ultimately prevailed on it, because the wrong is in how the process was used, not in whether it should have been brought at all. This makes abuse of process available in situations malicious prosecution cannot reach, such as ongoing litigation, but its narrower 'improper use, not improper initiation' focus also means a plaintiff cannot simply relabel a failed malicious-prosecution theory as abuse of process to avoid the favorable-termination and probable-cause requirements.

Courts are attentive to this overlap and will look closely at whether the plaintiff is really complaining about why the proceeding was brought (malicious prosecution territory) or about a specific improper use of a specific piece of process within it (abuse of process territory).

In Juricratic, abuse of process is modeled with the ulterior-purpose element and the willful-act element as two independently adjustable dials, distinct from the underlying proceeding's merits dial (which, unlike in malicious prosecution, does not gate the claim). You can set the underlying case's strength and outcome as a separate, non-blocking input, and separately dial the strength of evidence for a collateral improper purpose (documented threats, timing of process tied to unrelated demands, use of process components beyond their intended scope). This lets the simulation show how an abuse-of-process theory can survive, or even strengthen, in scenarios where a parallel malicious-prosecution theory on the same facts would fail for lack of favorable termination or probable cause.