Lawsuit stages can vary depending on court rules, the nature of the dispute, and parties' resources. Generally, a trial level lawsuit can be roughly explained in four stages. Please remember that a dispute may be resolved at any stage or even before the lawsuit is filed.
1. Pleading stage. A lawsuit starts with the pleading stage when the plaintiff files a complaint, obtains summons, serves summons and the complaint on the defendant. The defendant responds to the complaint either through "answer" or other papers, such as a motion to dismiss, demurrer, motion to strike, motion to change venue, objections to jurisdiction, and the like. If the defendant does not respond on time, the plaintiff may request to enter a default and then apply for a default judgment.
2. Discovery. At this stage, parties may request documents, and send requests for admission and interrogatories. The other party has to respond and produce the requested information unless this information is privileged or protected. Parties may also subpoena information from non-parties.
After the written information is gathered, parties may start depositions. A deposition is a semi-official proceeding (without a judge, but with a court reporter) where an attorney can ask the deponent various questions. The deponent has to respond under oath unless there is a valid privilege, in which case the deponent may refuse to respond.
Depending on the case, parties may also conduct "expert discovery." They hire experts, exchange expert reports, and do depositions of the experts.
3. Motions. Throughout the lawsuit, parties may file various motions, such as motion for summary judgment, motion for judgment on the pleadings, application for attachment, motions related to admissibility of evidence at trial, motion for bifurcation, and other motions.
4. Trial and post-trial. Trials consist of each party presenting its evidence to the judge and the jury (or just the judge without jury). Attorneys may also consider motions after the trial. After the trial-level decision, depending on the grounds, the decision may be appealed.