Defendants must be told they have been sued. A summons is a formal legal notice issued by a court that informs a person of a lawsuit or proceeding and requires a response or appearance within a specified time.

In civil cases the summons accompanies the complaint and is served with it. Failure to respond can lead to default judgment. Criminal summonses may order appearance to answer charges without immediate arrest. Contents and service methods are strictly regulated to protect due process.

Proof of service establishes that the court may proceed. Defective summonses or improper service can delay or invalidate proceedings. Receiving a summons is the moment when legal risk becomes concrete and deadlines begin to run.

• Official notice of a legal proceeding
• Requires timely response or appearance
• Served with the complaint in civil cases
• Improper service can undermine jurisdiction