Inertia is the resistance of any physical object to any change in its state of motion; this includes changes to its speed, direction or state of rest. It is the tendency of objects to keep moving in a straight line at constant velocity. The principle of inertia is one of the fundamental principles of classical physics that are used to describe the motion of objects and how they are affected by applied forces. Inertia comes from the Latin word, iners, meaning idle, sluggish. Inertia is one of the primary manifestations of mass, which is a quantitative property of physical systems. Isaac Newton defined inertia as his first law in his Philosophiæ Naturalis Principia Mathematica:
The vis insita, or innate force of matter, is a power of resisting by which every body, as much as in it lies, endeavours to preserve its present state, whether it be of rest or of moving uniformly forward in a straight line.
SCUM features a dynamic inertia system that affects all kinds of movement and takes into account the weight of the overall character and his/her gear. Players with heavier characters will be more affected by inertia than players with slim characters. Taking too much equipment to fist fight will not just increase fatigue and stamina drops, this weight will also slow down characters significantly. The only way to make your character more agile is to lose excessive weight , either by dropping gear on the ground or lowering body fat percentage (in the longer run).