Since a round is roughly a minute long, it should be easy for a character to move just about anywhere he wants during the course of the round. After all, Olympic-class sprinters can cover vast amounts of ground in a minute.
However, a character in an AD&D game is not an Olympic sprinter running in a straight line. He is trying to maneuver through a battle without getting killed. He is keeping his eyes open for trouble, avoiding surprise, watching his back, watching the backs of his partners, and looking for a good opening, while simultaneously planning his next move, sometimes through a haze of pain. He may be carrying a load of equipment that slows him down significantly. Because of all these things, the distance a character can move is significantly less than players generally think.
In a combat round, a being can move up to 10 times its movement rating (see Chapter 14: Time and Movement) in feet. Thus, if a character has a movement rating of 9, he can move up to 90 feet in a round. However, the types of moves a character can make during combat are somewhat limited.
Movement in Melee
The basic move is to get closer for combat--i.e., move close enough to an enemy to attack. This is neither a blind rush nor a casual stroll. Instead, the character approaches quickly but with caution. When closing for combat, a character can move up to half his allowed distance and still make a melee attack.
Movement and Missile Combat
Rather than slug it out toe to toe with an opponent, a character can move up to one-half his normal movement rate and engage in missile fire at half his normal rate of fire. Thus, a man capable of moving 120 feet and armed with a long bow (two shots per round, under normal circumstances) could move 60 feet and still fire one shot. The same man, armed with a heavy crossbow (one shot every other round) would be able to shoot only once every four rounds while on the move.
Charging an Opponent
A character can also charge a foe. A charge increases the character's movement rate by 50% and enables the character to make an attack at the end of his movement. A charging character also gains a +2 bonus to his attack roll, mainly from momentum. Certain weapons (such as a lance) inflict double the rolled damage in a charge.
However, charging gives the opponents several advantages. First, they gain a -2 bonus to their initiative rolls. Second, charging characters gain no Dexterity bonuses to Armor Class and they suffer an AC penalty of 1. Finally, if the defender is using a spear or polearm weapon and sets it against the charge (bracing the butt against a stone or his foot), he inflicts double damage on a successful hit.
To get out of a combat, characters can make a careful withdrawal or they can simply flee.
Withdrawing: When making a withdrawal, a character carefully backs away from his opponent (who can choose to follow). The character moves up to 1/3 his normal movement rate.
If two characters are fighting a single opponent and one of them decides to withdraw, the remaining character can block the advance of the opponent. This is a useful method for getting a seriously injured man out of a combat.
Fleeing: To flee from combat, a character simply turns and runs up to his full movement rate. However, the fleeing character drops his defenses and turns his back to his opponent.
The enemy is allowed a free attack (or multiple attacks if the creature has several attacks per round) at the rear of the fleeing character. This attack is made the instant the character flees: It doesn't count against the number of attacks that opponent is allowed during the round, and initiative is irrelevant.
The fleeing character can be pursued, unless a companion blocks the advance of the enemy.