'Range' refers to the relative distance between two participants in a violent situation. This is most commonly used when discussing striking methods.
Difficulties with Vague Range Notation
Range notation is typically rather vague, either taking the form of 'short, medium and long range', or 'grappling range, punching range and kicking range', as two common examples. The issue with these vague notation methods arises when they are applied to systems which are diverse and adaptive in their methodology (particularly in their striking).
For example, if a range of less than half an arm's distance is referred to as 'grappling range', this suggests that striking will not be effective at that range. A 'short-range' kick may strike equally far away as a 'long-range' punch, and so these expressions become a little confusing and less usefully descriptive than they may seem at first.
Simple Range Notation
ESP practitioners in in-depth discussion will often prefer to use a simpler, numerical system to describe ranges. Particularly in textual discourse (such as this wiki), it makes things very clear avoids any confusion or vagueness.
Range 1: Target is ≤ 1 hand's length away from the person.
Range 2: Target is ≈ ½ an arm's length away from the person.
Range 3: Target is ≈ ½ 1 arm's / ½ a leg's length away from the person.
Range 4: Target is ≈ 1 leg's length away from the person.
Range 5: Target is further away than Range 4 from the person but is reached by something still connected to the person.
Range 6: Target is reached by something that leaves the person in order to impact it.
Examples of The Ranges
Range 1 typically includes lots of grappling, very short strikes employed in a clinch or grappling situation, headbutts, etc.
Range 2 typically includes short strikes: hook punches, short hammer fists, uppercuts, elbow strikes, longer headbutts, etc as well as some biomechanical manipulation. It also includes most attacks with a knife.
Range 3 typically includes knee strikes and elongated punches such as hammer fists, jabs and crosses, etc, as well as short kicks such as oblique kicks, jab kicks, hook kicks and side kicks to the knee, shin, ankle or foot.
Range 4 typically includes longer kicks such as jab kicks, side kicks, etc as well as strikes from short weapons such as bottles and other small objects.
Range 5 typically includes longer strikes from weapons such as sticks, machetes, swords, etc.
Range 6 could be anything from a thrown object, a firearm or explosives.