Knowledge of unit commands isn’t enough to win - you need to use them skillfully to control your units. Listed below are some basic tips for unit control.
Learn to ”stutter step”/”kite”
To use ranged units effectively, you need to hit and run. If your opponent charges your ranged units with melee units, run away, stop and fire, then repeat this process until the enemy units are dead. Often, your opponent will give up the chase, at which point you can fire from range without taking any damage.
Macro vs. Micro
Learning how to hit-and-run (attack quickly, then back off, regardless of whether or not your objective is destroyed), and how to deal with other players using this technique can significantly improve your game.
First, don’t be afraid to run away when a battle turns against you. You can flee to defensive structures (like photon cannons, bunkers, spine crawlers, etc.), allied armies, or your reinforcements. You should always choose to run away over continuing to fight a battle that you are not going to win.
Hit-and-run attacks can bait the enemy into traps (such as a line of defensive structures). If your enemy is outside your base and you have several cannons or turrets, you can send out one ranged unit, attack the enemy, and then retreat inside your base, causing them to give chase unless they’re using the Hold Position command.
The Run Around
When you tell a group of units to attack a single enemy, they will attempt to reach that enemy by moving towards it until they can get a clear shot. This can result in a lot of time spent wandering (with units’ paths becoming blocked by other units) rather than attacking. Try to limit the time your units spend not attacking enemies by using the Attack-Move command.
The more units you have attacking the same enemy, the quicker that enemy will be killed and allow you to focus on your next target. In general, focusing fire (commanding all of your units to attack the same unit) is an ideal tactic, but beware - if one of your units cannot easily reach the preferred target, you should instead instruct it to attack the nearest enemy so that it continues contributing to the battle. If you find yourself focusing fire regularly, keep an eye out for enemy units that retreat while they’re under attack – your units may chase retreating units, causing them to spend time moving rather than fighting. If you use the Attack-Move command instead of attacking a single unit, your units will attack the next closest unit rather than chasing a single retreating unit.
Keep All Units Together When Attacking
It's quite common to send a force out and see them separated due to enemy attacks, unit movement speed or terrain. Before attacking, make sure you group all units together outside the enemy base or targeted location. A larger force can be defeated by a small number of grouped enemy units.
Get rid of dangerous targets
If you see especially dangerous units (for example, high templar, medivacs, infestors, siege tanks, etc.) or support units, target them and pick them off.
If you're mostly attacking enemies and not taking damage or defending, promptly research damage upgrades. If you’re both attacking your enemy and defending against regular assaults, rotate between damage and armor upgrades. Research increased range upgrades whenever possible.
Queuing Enemy Targets
It can be very useful to queue up a list of targets for ranged attackers, freeing your focus up while these units fight on their own. To do so, simply select a group of ranged units, hold down the Shift key and hit A for attack (or right-click) and select all the enemy units you want to attack. When you release Shift, your ranged units will attack their targets in order.