Understanding Textual Close Quarter Combat for the Aspiring Duelist-
By RM Wright, aka Skallagrim 

Close Quarter Combat: Noun1. close-quarter fighting - hand-to-hand fighting at close quarters fighting, combat, fight, scrap - the act of fighting; any contest or struggle; "a fight broke out at the hockey game"; "there was fighting in the streets"; "the unhappy couple got into a terrible scrap"

As defined by U.S. Army FM 3-25.150 Combatives:

1-1. Hand-to-hand combat- Hand-to-hand combat is an engagement between two or more persons with or without hand-held weapons such as knives, sticks, or projectile weapons within the range of physical contact.

1-2. Combatives- Combatives are the techniques and tactics useful to Soldiers involved in Hand-to-hand combat. Proficiency in Combatives is one of the fundamental building blocks for training the modern Soldier.

If you want to learn to be a good CQB combatant in textual fighting and bring more realism to your fights you will need to know the 8’s. The 8’s are the basis of all hand to hand fighting be it martial arts with hands and feet or weapons. Besides the eights you will need to know the three basic guards. It is from the guards all your attacks will come but more of that later. Melee combat can then be boiled down to what I call 3-8-8. 

The basic guards are-

1- High Guard
2- Middle Guard
3- Low Guard

Your high guard will place a weapon up to protect your head and shoulders.  
The middle guard places your weapon before your torso protecting from your shoulders to your groin. The low guard protects your groin to your ankles.

From any guard you are able to attack based on the 8s. You will have to make sure your writing flows with your imagination and your actions but if done well it all works together.

Mobility-

The first thing you need to focus on is your footwork. It is from your footwork that you can move and attack, or dodge and evade an attack. This is the first 8, the eight paths of movement.

In any combat situation you can only move in eight (8) directions-

1- Forward
2- Forward Right
3- Right
4- Back Right
5- Back
6- Back Left
7- Left
8- Forward Left.

This is it. If you stand up you can see the directions naturally. If you step forward or to the right you use your right foot. If you step forward and left it is your left foot that leads unless you do a crossing move in that direction. Crossing moves are called transitional movements because they take you from one place to another and adjusts your body position, slightly but provides for more offense or defense if done away from or towards your opponents dominant hand. 

In any fight, real or imagined, everything takes places with these movements. Watch any boxing match, or MMA fight and see where the fighters place their feet. Someone is moving forward in one of those directions and the corresponding footwork backward is conducted by the other fighter. So if you understand how your character is moving, you will see how your opponent will naturally move to get away from you, or move to meet you.

A key to helping you understand spatial placement during the move is that the average man's stride is 18 inches from heel to heel. Thus if you move you can be reasonably accurate in your distances if you keep this in mind. A crossing move would place you 36 inches away if you are moving to dodge or flank, thus you are three feet from your opponent. Taking that into consideration, with a sword you might be away but able to still strike effectively.

This is a key factor because you will be able to predict the most likely direction an attack will come and defend it in a logical way that will give you the advantage in the fight.

Attack Angles and Zones-

The second 8 is the angles of attack: They also come from the eight points on the compass. Imagine the human body radiates the compass points outward starting with the high or head spot. You can see a progression from head to shoulder/chest to stomach/groin to upper legs to calf/feet and back up on the left side.

1- High
2- High Right
3- Right
4- Low Right
5- Low
6- Low Left
7- Left
8- High Left.

It is from these directions all your attacks will come.  And it is from these directions that you will be able to see the most logical way your opponent will defend your attack.  Once you can predict this you can start to think a move or two ahead to see what you can do to get the killing blow.

Thus if you have a sword in a high guard, it will be up near your shoulders protecting your head. From here you can swing to the high, high right or high left naturally.  However, you can also attack right, low right, low left or left as easily by moving along the corresponding eight paths and then striking along the 8 angles open to you.

For instance you have a right-handed high guard with a long sword. Your opponent has a long sword in a right-handed middle guard. You move right then forward right to get an angle on your foe. By these two moves you are now on his left flank he has to turn to face you, since your movement places you outside of the natural range of his sword you can attack to the high, high right, right or low right areas of his body. These correspondingly are the head, left shoulder, left arm, left torso or left upper thigh. 

Remember every move you make is opposite to your opponent. If you move right it is his left. If you move left it is his right. Always describe your moves from your perspective and when describing where you are hitting from his perspective.

i.e. I swing my war sword from the high guard into a quick right strike to the torso with the blade arcing down in a blur towards the exposed ribs on the left side of my opponent. 

If you can learn these basic lessons and master them you will be able to meet any melee attacker and hold your own against them. Eventually everything you do you can predict the outcome by virtue of the movements and narrow down the options your opponent has in which to counter you and if they are not knowledgeable in movements and angles, you can beat them.

Things to remember when text fighting with swords or other melee weapons:

Attack and counter-attack: The primary tactical principle for all text fights is that for every attack there is a counter-attack. Opponent’s attacks are met with counter-cuts and thrusts that set aside the opponent’s weapon to force a way through their guard. Counters can be combined with avoidance, grapples and disarms to make them defenseless. 

Avoidance: The first and most basic defense to a fighter is to not be where the weapon strikes. This may be accomplished by stepping back and out of range. However with a sword or any weapon that is being used in a swinging attack, the best method is to step into the opponent directly or at an angle to either side and counter-attacking. 

Setting Aside: Attacks may be countered by setting them aside with your own weapon. This is similar to a parry. Setting aside is an action that happens two ways, by either cutting into it to strike the opponent by passing through his own attack, or by redirecting the blow with your own weapon to gain an advantage over your opponent. Well executed setting aside techniques are fluid and naturally set-up a counter attack. 

Grappling: When the distance is closed and the length of weapons make strikes ineffective, grappling is used to regain proper fighting distance, to throw an opponent off-balance or disarm them. 

While many other techniques are used in actual sword fighting, understanding the basic movement patterns and striking options will help develop the scene you want to create. Understanding when and how to use counters, avoidance, setting aside and grappling can make you a great text-based writer who creates compelling fighting scenes and sequences.