Reduction in rank may refer to three separate concepts:In military law, a reduction in rank or degradation is a demotion in military rank as punishment for a crime or wrongdoing, imposed by a court-martial or other authority. It may be imposed in conjunction with other punishments, such as a bad conduct or dishonorable discharge, loss of wages, confinement to barracks, or imprisonment in a military prison. Reduction in rank may also refer to the voluntary, non-punitive practice of taking a lower rank, often as part of joining another military unit or military service. For example, those who join the Special Air Service or Australian Special Air Service Regiment take the rank of trooper, often a lower rank than their previous rank but with greater pay, prestige, and responsibilities. There is a reversion in rank after an officer has been temporarily promoted to a higher rank while occupying a position requiring that rank; the officer reverts to the permanent rank on vacating the position bearing the higher rank. This occurs often in the U.S. military, to three- or four-star general or flag officers, who can be reduced in rank to no lower than their permanent rank of two-stars, as all ranks above two-stars are temporary, and are linked to their position's office. Reversion of this type is less usual for lower U.S. military ranks as such temporary promotions are uncommon.

As with most other military forces the Roman military adopted an extensive list of decorations for military gallantry and likewise a range of punishments for military transgressions.