A Court Martial is a special Court which has jurisdiction to try persons who are subject to Service Law. Members of the Armed Forces; the Army, the Navy and the Air force are persons who can be tried by a Court Martial, because they are persons subject to Service Law. In a case where a person has ceased to be subject to Service Law, he cannot be tried by a Court Martial for an offence which he committed while he was still in Service, unless his trial is commenced within three months after he ceased to be subject to service Law.
A person subject to Service Law would cease to be subject to Service Law if he retires, resigns or is discharged from the Armed Forces.
It is ad hoc and has to be convened to deal with specific offence(s) by the military personnel against the ordinary law of the land or military discipline. There is no court in existence which is referred to as a Court Martial; it is said to be adhoc because it is usually set up or convened by authorised persons to try offences committed by a member of the Armed Forces and it is dissolved at the end of the trial of the offence for which it was set up. A court Martial is also known as a Military Court.
Members of the Nigerian Armed forces are subject to the same laws that govern Civilians and they are also subject to some special laws which regulate their conduct as members of the Armed Forces. They can be tried in a Civil Court of Law as well as in a Military court. It is erroneous to think that a member of the Military cannot be tried by a regular/civilian court. A Civil Court can try a person subject to service Law for an offence contrary to the Criminal Law or Penal Law and not for a Military offence. Civilians cannot be tried by a Court Martial. A Court Martial cannot exercise jurisdiction in a civil matter even if it involves a person subject to Service Law.
The jurisdiction of the Court Martial extends to military offences and offences committed contrary to the penal law of Nigeria by a person subject to Service Law; thus, if a person subject to Service Law commits the offence of rape, he can be tried by either a Civil Court or by a Court Martial. A Court Martial can upon convicting a person charged with an offence impose any punishment prescribed by law, it can impose any punishment which a High Court can impose and it can impose additional punishments prescribed by the Armed Forces Act such as Dismissal or reduction in rank, or forfeiture of seniority in the rank.
A Court Martial could either be a General Court martial or a Special Court Martial. The difference between a General Court Martial and a Special Court Martial lies in their number and the punishment they can impose.
A General Court Martial consists of a President and not less than four members, a waiting member, a liaison officer and a Judge advocate, while a Special court-martial, consists of a President and not less than two members, a waiting member, a liaison officer and a Judge advocate.
A waiting member is a person who is to perform or stand by to take the place or position of a member of the panel of the Court Martial who for one reason or the other is unable to sit in the panel and has to be substituted by another person already appointed or nominated to be a member in case of any eventuality, he can be likened to a spare tyre. He is not a member of the panel exercising judicial function.  A liaison officer means nothing more than an officer in military office whose duty is merely to co-ordinate or ensure proper co-ordination of activities. He is not a member of the court. The waiting member and the liaison officer are necessary adjuncts meant to situate the Court Martial in its proper context of the military. A Judge advocate is an officer of the Court Martial who acts as a prosecutor; his role is merely advisory.
A Special Court Martial cannot impose any punishment exceeding one year imprisonment or the death penalty if it consists of only two members.
Findings and decisions of the Court Martial are determined by a majority of the votes of the members of the court-martial. Where there is an equality of votes on the guilt or innocence of a person before a Court Martial, the Court Martial shall acquit the accused. A Court Martial can only impose the death penalty if there is a concurrence of all the members of the Court Martial in a case where death penalty is the mandatory punishment prescribed for the offence. Where death penalty is not a mandatory punishment and the law prescribes a lesser punishment, that lesser punishment can be imposed where there is no concurrence of all the members of the Court on the death penalty.
The finding of guilt and any sentence or punishment imposed by the Court Martial is subject to confirmation by a higher authority.
A Court Martial like a Civil Court cannot sit on a Sunday or on a public holiday unless the convening officer or the Court Martial is of the opinion that the exigencies of service make it expedient to do so.
person appearing before a Court Martial has a right to be represented by a
Legal Practitioner of his choice.
 Samuel & Ors. V. Nigerian Army (2006) LPELR-11751(CA)
 Obisi V. Chief Of Naval Staff (2004) LPELR-2184(SC)
 Obisi V. Chief Of Naval Staff