A lawsuit is a formal civil dispute brought before a court, where one party (the plaintiff) asks a judge or jury to order another party (the defendant) to pay money or to take or stop a specific action. Unlike criminal cases, where the government prosecutes someone for breaking the law and jail time is on the table, a lawsuit is a private matter between people, businesses, or organizations. The goal is to make the injured party whole, usually through financial compensation, rather than to punish anyone. Knowing how a lawsuit works helps you make better decisions whether you are thinking about filing one, responding to one, or just trying to understand what you have been pulled into.
Who Is Involved
The person or organization that files is called the plaintiff. The plaintiff carries the burden of proving the claims, meaning they have to present enough evidence to show their version of events is more likely true than not.1Justia. Evidentiary Standards and Burdens of Proof in Legal Proceedings The person or organization being sued is the defendant, who must respond to the allegations within a court-imposed deadline. Either side can be an individual, a business, a nonprofit, or a government agency.
A judge oversees the case to make sure both sides follow the rules, and in many cases a jury decides the factual disputes. Both parties usually hire attorneys, though you have the right to represent yourself. Courts call self-represented litigants “pro se.” The option exists, but going it alone carries real risk: you are held to the same procedural rules as a licensed attorney, and missing a deadline or filing the wrong document can end your case before it starts.
Defendants are not limited to playing defense. Under the federal rules, a defendant who has their own claim against the plaintiff arising from the same set of events must raise it as a counterclaim in their answer or lose the right to bring it later.2LII / Legal Information Institute. Federal Rules of Civil Procedure Rule 13 – Counterclaim and Crossclaim A defendant can also raise unrelated claims as a permissive counterclaim. A lawsuit can quickly become a two-way street.
Common Types of Lawsuits
Civil litigation covers an enormous range of disputes, but most cases fall into a handful of categories. Tort claims make up a large share, covering situations where someone’s negligence or intentional wrongdoing caused physical injury or financial harm — car accidents, slip-and-fall injuries, medical malpractice, and defamation all fall here. Breach of contract cases arise when one side fails to uphold a written or oral agreement. Property disputes involve land boundaries, ownership, easements, or landlord-tenant issues. Family law handles divorce, child custody, and the division of assets. Employment lawsuits address wrongful termination, discrimination, or wage theft.
When a large number of people suffer the same harm from the same defendant, one or more of them can file a class action on behalf of the entire group — think of defective products that injured thousands of consumers, or a company that overcharged millions of customers by the same amount. A class action has to meet strict requirements before a court will let it proceed as one case rather than many.3Legal Information Institute (LII) / Cornell Law School. Federal Rules of Civil Procedure Rule 23 – Class Actions
What You Need Before You Can File
Two threshold hurdles trip up more would-be plaintiffs than you would expect.
Standing
You cannot sue just because something bothers you. Under Article III of the Constitution, a plaintiff must show three things: they personally suffered an actual or threatened injury, that injury is traceable to the defendant’s actions, and a court ruling in their favor would likely fix or compensate the harm.4LII / Legal Information Institute. Standing Requirement: Overview Miss any element and the court dismisses the case without ever looking at the merits.
The Filing Deadline
Every type of civil claim has a filing deadline called a statute of limitations. Miss it and your case is dead no matter how strong the evidence. These deadlines vary by claim type and state. Personal injury claims typically carry a deadline of two to three years in most states, though a few allow as many as six. Contract disputes generally allow three to six years for oral agreements and up to ten years for written ones. Property damage claims usually fall in the two-to-five-year range. The clock normally starts when the injury occurs or when you reasonably should have discovered it, though the exact trigger rules vary.
How Much Proof It Takes to Win
This is where civil and criminal law part ways. In a criminal trial, the prosecution must prove guilt “beyond a reasonable doubt,” the highest standard in the legal system. In a lawsuit, the plaintiff only has to show the claims are true by a “preponderance of the evidence” — more likely than not. Picture a scale tipping just slightly in one direction. The lower bar makes sense because nobody is going to prison; the question is whether someone owes money or needs to stop doing something. It also means some cases that do not result in criminal convictions can still succeed as lawsuits, which is exactly what happened in the O.J. Simpson case.
Filing a Lawsuit
The Complaint and Summons
A lawsuit starts when the plaintiff files a document called a complaint (some courts call it a petition). The complaint lays out the facts, identifies the legal basis for the claim, and states what the plaintiff wants — a specific dollar amount, an order requiring the defendant to do or stop something, or both. That request is formally called the “prayer for relief.”
Along with the complaint, the court issues a summons, the official notice telling the defendant they are being sued and have a deadline to respond. The plaintiff must file in a court that has jurisdiction, meaning both the authority to hear the type of dispute and power over the defendant, usually based on where the defendant lives or where the events occurred. Filing in the wrong court can get the case dismissed or transferred.
Filing Fees
Filing a complaint requires paying a fee. In federal district court, the standard filing fee is $405. State court fees vary widely depending on the court level and the amount being claimed, ranging from as little as $30 for small claims up to several hundred dollars for general civil cases. If you cannot afford the fee, you can apply for a fee waiver by filing an application that documents your financial situation. Courts grant these waivers for people whose income falls below certain thresholds.
Small Claims Court
For smaller disputes, most states offer small claims court, a simplified, faster process with lower filing fees and relaxed rules of evidence. Monetary limits vary by state, from as low as $2,500 to as high as $25,000. Attorneys are often not required and sometimes not even allowed. If your dispute fits within the dollar cap, small claims court can resolve it in weeks rather than months or years.
Accountability for Baseless Claims
When an attorney or party signs a complaint, they are certifying that the claims have a reasonable legal basis and factual support. If a court determines a filing was brought for an improper purpose or lacks any legitimate foundation, it can impose sanctions, including orders to pay the other side’s attorney fees or fines payable to the court.5Cornell University Law School – Legal Information Institute (LII). Federal Rules of Civil Procedure Rule 11 – Signing Pleadings, Motions, and Other Papers; Representations to the Court; Sanctions
The Stages After Filing
Service of Process
After filing, the plaintiff must formally deliver the summons and complaint to the defendant. This step is called service of process, and it ensures the defendant actually knows about the lawsuit. Service is typically handled by a process server, a sheriff’s deputy, or another adult who is not a party to the case. You cannot just hand the papers to the defendant yourself. Private process servers generally charge between $20 and $100 per job, with higher fees for defendants who are hard to locate.
The Defendant’s Response
Once served, the defendant has a limited window to file a written response called an answer. In federal court, the deadline is 21 days after service.6Cornell Law School Legal Information Institute (LII). Federal Rules of Civil Procedure Rule 12 – Defenses and Objections State courts set their own deadlines, commonly 20 to 30 days. The answer must address each allegation in the complaint, either admitting it, denying it, or stating that the defendant lacks enough information to respond.
Instead of answering, the defendant may file a motion to dismiss, arguing that the complaint fails for a procedural or legal reason, such as the plaintiff filing in the wrong court, missing the statute of limitations, or not stating a valid legal claim. If the court grants the motion, the case may end there, or the plaintiff may get a chance to refile a corrected complaint.
If the defendant ignores the lawsuit entirely and never responds, the plaintiff can ask the court for a default judgment, which essentially means the plaintiff wins because the other side did not show up.7LII / Legal Information Institute. Federal Rules of Civil Procedure Rule 55 – Default; Default Judgment The court may still hold a hearing to determine how much money is owed, but the defendant has already lost the chance to contest liability.
Discovery
Once both sides have filed their initial papers, the case enters discovery, the phase where each side investigates the other’s evidence. Discovery tools include depositions (live, sworn questioning of witnesses), interrogatories (written questions the other side must answer under oath), and requests for production (demands to hand over documents, emails, photographs, or other records). Discovery is designed to prevent ambush at trial. Both sides learn what the other has, which often clarifies whether a case is strong enough to take all the way to a verdict or weak enough that settling makes sense.
Discovery is also where costs escalate quickly. Reviewing thousands of documents, sitting through depositions, and hiring expert witnesses all take time and money. In complex commercial litigation, discovery alone can take a year or more.
Summary Judgment
After discovery closes, either side can ask the court to decide the case without a trial by filing a motion for summary judgment. The court grants the motion when there is no genuine dispute about the material facts and the law clearly favors one side.8Legal Information Institute (LII) at Cornell Law School. Federal Rules of Civil Procedure Rule 56 – Summary Judgment Many cases end here. If the evidence so clearly supports one party that no reasonable jury could disagree, there is no point holding a trial.
Trial
Cases that survive summary judgment proceed to trial, where a judge or jury hears live testimony, reviews evidence, and reaches a verdict. Most civil trials last a few days to a couple of weeks, though high-stakes or complex cases run longer. The entire timeline from filing to trial typically runs one to three years for straightforward cases and three to five years or more for complex litigation.
Settlement and Alternatives to Trial
The vast majority of lawsuits settle before trial. A settlement is a negotiated agreement where the defendant typically pays the plaintiff a sum of money in exchange for the plaintiff dropping the case and releasing all future claims related to the same incident. Settlements can happen at any stage — before filing, during discovery, on the courthouse steps the morning of trial. The parties control the terms, which often makes settlement more predictable than leaving the outcome to a jury.
Many courts encourage or require alternative dispute resolution. Mediation puts both sides in a room with a neutral mediator who helps them negotiate; the mediator has no power to force a result. Arbitration is different: an arbitrator hears evidence from both sides and issues a binding decision, much like a private judge. Many consumer and employment contracts include mandatory arbitration clauses, meaning you have already agreed to skip the courtroom before a dispute even arises.
How a Lawsuit Ends
Cases that go all the way through trial end with a judgment, the court’s official decision on who wins and what they are owed. Judgments are legally binding. A judge can also dismiss a case before trial if the plaintiff fails to follow court rules, misses deadlines, or does not present enough evidence to proceed.9Cornell Law School. Federal Rules of Civil Procedure Rule 41 – Dismissal of Actions A dismissal “with prejudice” means the plaintiff can never refile the same claim. A dismissal “without prejudice” leaves the door open to try again, assuming the statute of limitations has not expired.
Collecting a Judgment
Winning a judgment and actually collecting the money are two very different things. A verdict does not automatically put cash in your hands. If the losing party does not pay voluntarily, the winning party typically must obtain a writ of execution from the court, which authorizes a sheriff or marshal to seize assets. Common collection methods include wage garnishment, where a portion of the debtor’s paycheck is redirected to you, and bank levies, where funds are taken directly from the debtor’s account. If the defendant has no assets or income worth pursuing, even a million-dollar judgment can be worthless on paper.
Appeals
The losing party can challenge the outcome by filing an appeal. In federal court, a notice of appeal must be filed within 30 days after the judgment is entered.10LII / Legal Information Institute. Federal Rules of Appellate Procedure Rule 4 – Appeal as of Right; When Taken When the federal government is a party, that deadline extends to 60 days. State appellate deadlines vary but are similarly strict. An appeal does not retry the case with new evidence. The appellate court reviews whether the trial court made legal errors. Most judgments are upheld, but when an error affected the outcome, the appellate court can reverse the decision or send the case back for a new trial.
What a Lawsuit Costs
Beyond filing fees, litigation costs add up in ways that catch people off guard. Attorney fees are the biggest expense for most litigants. In personal injury and some employment cases, attorneys often work on a contingency fee basis, taking a percentage of the recovery (typically between 33% and 40%) and charging nothing upfront if the case loses. For other types of cases, attorneys bill hourly, and rates vary enormously by market and experience level.
Expert witnesses, when needed, can cost anywhere from $300 to $600 per hour for medical experts, with top specialists charging significantly more. Deposition transcripts, document production, court reporter fees, and travel costs all contribute to the total. In a relatively simple case, litigation costs outside of attorney fees might run a few thousand dollars. In complex commercial disputes, six-figure litigation budgets are common. Understanding these numbers upfront helps you make a realistic assessment of whether pursuing or defending a lawsuit is worth it financially.