Mo. R. Civ. P. 78.01
The court may grant a new trial of any issue upon good cause shown. A new trial may be granted to all or any of the parties and on all or part of the issues after trial by jury, court or master. On a motion for a new trial in an action tried without a jury, the court may open the judgment if one has been entered, take additional testimony, amend findings of fact or make new findings, and direct the entry of a new judgment.
Mo. R. Civ. P. 78.01
Committee - 1974
The source is prior Rule 78.01. In revising prior Rule 78.01, there is no intention to eliminate any of the reasons for which new trials heretofore have been granted or to change the law concerning the grounds for granting a new trial. The revision has been made solely to make the Rule more concise.
Compare: Rule 59(a) of the Federal Rules of Civil Procedure.