- Disambiguation: Maneuver Defense was formerly known as Combat Maneuver Defense (CMD)
- Each character and creature has a Maneuver Defense value that represents its ability to resist combat maneuvers such as Trip, Overrun and Bull Rush, among many other uses. Maneuver Defense can be thought of as a general statistic used to represent how well a character or creature can handle rough physical treatment. It is related to but different than Armor Class, and is derived in a different way. Maneuver Defense is based on a characters overall experience with the school of hard knocks, the physical size, power, and deftness of the character, combined with their ability to dodge or deflect events. A Player Character's exact Maneuver Defense is determined using the following formula:
| 10 + ½ Character Level (Round Down) + Size Modifier + STR modifier + DEX modifier + Dodge AC + Deflection AC + Miscellaneous + Penalties
- Size Modifier: Fine -4, Diminutive -3, Tiny -2, Small -1, Medium +0, Large +1, Huge +2, Gargantuan +3, Colossal +4, Titanic +5.
- Miscellaneous Modifiers: Some feats and abilities grant a bonus to your Maneuver Defense when resisting specific things.
- Penalties: Any penalties to a creature's AC also apply to its Maneuver Defense for physical attacks. For example, a flat-footed creature does not add its Dexterity bonus to its Maneuver Defense against a Trip maneuver.