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In criminal trials in certain United States jurisdictions, it is a plea where the defendant neither admits nor disputes a charge, serving as an alternative to a pleading of guilty or not guilty. A no-contest plea, while not technically a guilty plea, has the same immediate effect as a guilty plea and is often offered as a part of a plea bargain.  In many jurisdictions a plea of nolo contendere is not a typical right and carries various restrictions on its use.
In the United States, State law determines whether, and under what circumstances, a defendant may plead no contest in state criminal cases. In federal court, the Federal Rules of Criminal Procedure only allow a nolo contendere plea to be entered with the court's consent; before accepting the plea, the court is required to "consider the parties' views and the public interest in the effective administration of justice". 
A nolo contendere plea has the same immediate effects as a plea of guilty, but may have different residual effects or consequences in future actions. For instance, a conviction arising from a nolo contendere plea is subject to any and all penalties, fines, and forfeitures of a conviction from a guilty plea in the same case, and can be considered as an aggravating factor in future criminal actions. However, unlike a guilty plea, a defendant in a nolo contendere plea may not be required to allocute the charges. This means that a nolo contendere conviction typically may not be used to establish either negligence per se, malice, or whether the acts were committed at all in later civil proceedings related to the same set of facts as the criminal prosecution. 
Under the Federal Rules of Evidence,   and in those states whose rules of evidence are similar or identical to them, nolo contendere pleas may not be used to defeat the hearsay prohibition if offered as an "admission by [a] party-opponent".  Assuming the appropriate gravity of the charge, and all other things being equal, a guilty plea to the same charge would cause the reverse effect: An opponent at trial could introduce the plea, over a hearsay objection, as evidence to establish a certain fact. 
In Alaska, a criminal conviction based on a nolo contendere plea may be used against the defendant in future civil actions. The Alaska Supreme Court ruled in 2006 that a "conviction based on a no contest plea will collaterally estop the criminal defendant from denying any element in a subsequent civil action against him that was necessarily established by the conviction, as long as the prior conviction was for a serious criminal offense and the defendant in fact had the opportunity for a full and fair hearing".  
In California, a nolo contendere plea is known as a West plea after a seminal case involving plea bargains, People v. West (1970) 3 Cal.3d 595. The state Board of Pharmacy considers a plea of nolo contendere to be deemed a conviction with regard to issuing licenses for pharmacies, pharmacists and drug wholesalers.
If one pleads nolo contendere to a felony in California, the plea is recognized as a felony while if one pleads nolo contendere to any other crime, no guilt is admitted and such person is immune from civil liability. 
In Michigan, "A nolo contendere plea does not admit guilt, it merely communicates to the court that the criminal defendant does not wish to contest the state's accusations and will acquiesce in the imposition of punishment." Lichon v American Universal Insurance Co., 435 Mich 408, 417 (1990). A nolo contendere plea may be appropriate "where the defendant would not be able to supply a sufficient factual basis for a guilty plea because he or she was intoxicated on the night of the incident, where there is the possibility of future civil litigation resulting from the offense, or where a defendant cannot remember the events which led to his or her being charged with a crime". 1A Gillespie Michigan Criminal Law & Procedure, § 16:15.
A no contest plea prevents the court from eliciting a defendant's admission of guilt, but the result of the defendant's plea not to contest the charges against him or her is the same as if the defendant had admitted guilt. If a defendant pleads no contest to a charged offense, with the exception of questioning the defendant about his or her role in the charged offense, the court must proceed in the same manner as if the defendant had pleaded guilty. MCL 767.37. A plea of no contest to a felony offense requires the court's consent. MCR 6.301(B).
A defendant's no contest plea to criminal charges does not estop that defendant from denying responsibility in a later civil action arising from the same conduct. Lichon, 435 Mich at 417.
In Texas, the right to appeal the results of a plea bargain taken from a plea of either nolo contendere or "guilty" is highly restricted. Defendants who have entered a plea of nolo contendere may only appeal the judgment of the court if the appeal is based on written pretrial motions ruled upon by the court. 
In the Commonwealth countries—such as England and Wales, Canada, and Australia—the plea of nolo contendere is not permitted. The defendant must enter a plea of "guilty" or "not guilty". If a defendant refuses to enter a plea, the court will record a plea of "not guilty". 
- Stephano Bibas (July 2003). "Harmonizing Substantive Criminal Law Values and Criminal Procedure: The Case of Alford and Nolo contendere Pleas". Cornell Law Review. 88 (6). Retrieved May 10, 2007.
- Legal Information Institute. "United States Federal Rules of Evidence, Rule 410(2)". Cornell Law School. Retrieved April 22, 2010.
- Legal Information Institute. "United States Federal Rules of Evidence, Rule 803(22)". Cornell Law School. Retrieved April 22, 2010.
- Legal Information Institute. "United States Federal Rules of Evidence, Rule 801(d)(2)". Cornell Law School. Retrieved April 22, 2010.
- "Drunk driver who pled no contest can't relitigate issue of recklessness",All Business, December 18, 2006, retrieved April 22, 2010
- "Lamb v. Anderson No. 6078 (S-11936), P3d 736". Alaska Supreme Court. November 17, 2006.
- Cal. Penal Code § 1016
- "Sheldon Montgomery vs. Florida" (PDF). Florida Supreme Court. March 17, 2005.
- "Texas Rules of Appellate Procedure, Rule 25.2(a)" (PDF). Supreme Court of Texas. Retrieved April 16, 2014.
- David J. Wills (2007). "Different State jurisdictions govern the plea process through their own legislation" (PDF). Division 3 Sections 146 146A.