In criminal law, conspiracy is an agreement between two or more people to commit a crime or accomplish an illegal purpose.
In order to be convicted of conspiracy, it is generally necessary to prove that the defendant entered into an agreement with at least one other person to commit a crime and that the defendant took some overt act in furtherance of the agreement.
Conspiracy is often charged as a separate offense in addition to the underlying crime that was the subject of the agreement. For example, suppose two people agree to rob a bank, and one of them actually carries out the robbery. In that case, both people could be charged with conspiracy to commit bank robbery and the underlying crime of bank robbery.
The penalties for conspiracy can vary depending on the jurisdiction and the severity of the underlying crime that was the subject of the agreement. In some cases, the penalties for conspiracy may be the same as those for the underlying crime or even greater.