The NC Combat System is intended to be a modular replacement for the combat system utilized in the standard Advanced Dungeons & Dragons rules. The system is completely different and novel. Characters have additional Attributes to support the system, including Offense Ability, Defense Ability, Armor Value, and Damage Reduction.
Hit Points are not much improved by Class and Level, but represent size and toughness. They also are "scaled up" so that a human character will have around 60 (average) to 100 (robust) hit points. Weapons cause ten times the damage as previously (e.g., a longsword does 10-80 points of damage). Rest and recovery are much, much slower than previously. Combat supports critical hits and saving rolls. The amount of time in a combat round is adjusted and various actions are specified in terms of segments.
Generally speaking, the combat in The NC Combat System is more complex than that in the AD&D system but also is much more consistent in approach. The intent of the system was to simplify operation, shorten play time, and present a more "realistic" combat action.