Combat is a way of life. Master the basics of fighting before you jump headlong into the game, or risk a premature trip to the afterlife. Read on and get educated.
Before you enter a mission or explorable area (in other words, before you leave town), load your Skill Bar with the eight skills you think will serve you best in the coming conflict. At the start of the game you'll have empty space, but as you learn and earn more skills you'll need to be selective in how you equip your character's skills.Your hero's armor (courtesy of your primary profession) is already equipped—make sure your chosen weapon is at the ready and that any alternate weapons are loaded onto the quick weapon menu (keys F1-F4).
Equip weapons and armor from your Inventory, which manages the items you have acquired. Double-click on a weapon or piece of armor in your Inventory to equip it.
Virtually anywhere you travel outside the safe confines of a town, you are likely to encounter hostile creatures that will happily eat you and/or your party for lunch. This kind of combat is referred to as PvE (for Player vs. Environment) or PvM (Player vs. Monster).
To quickly target and attack the nearest creature, press Tab to highlight an enemy, and then press Space to attack. Tab targeting allows you to cycle through the enemies that you can see on your compass. To reset the cycle you can press the \ key to re-target the closest foe. This is useful when you are involved in an especially intense melee—enemies move around while you're fighting them, and if you only use the Tab key you might unintentionally target a distant foe, thus drawing more hostiles to your location before you and your team are ready to deal with them.
You can target allies by clicking on the ally's name in the Party menu or by selecting the actual ally. When you've targeted a friendly, you can perform various actions on them. You can heal allies, open a Trade window (by clicking the Trade button at the top of the screen), and follow the ally by hitting the Space Bar (note that once you catch up to the ally, you will need to hit the Space Bar again to keep following). The follow command is useful when a group leader is guiding others through an unfamiliar area.
Calling Your Target
You can effectively coordinate attacks by "calling the target." To call your target, first target the enemy with Tab or by left clicking on the enemy's name. Hold down the Ctrl key and hit the Space bar (or the number for the skill you're using) to start your attack. Your character will automatically send a message to the party declaring "I'm attacking [enemy's name]!" You will also see a small crosshair icon appear next to your name on the Party menu. Other party members need only left-click on the crosshair and they will target the exact same foe you are going after. Focusing on a single foe is an excellent strategy—most groups will home in on the enemy's healer or healers at the onset of a battle, or will gang up on an especially tough boss character. Calling targets works just as well in PvE as it does in PvP. Most groups like to assign calling to an individual player, often a ranged attacker who will be pulling enemies toward you or a tank character that will be running into the fray.
Communication Made Easy
The same principle that lets you call targets also gives you a quick and simple method for communicating with your party in the heat of battle without the distraction of typing words. The Crtl + command trick works with just about every command and with many interface elements. For example, say you want to find out (and share) your level and how far away you are from earning your next level. Just hold down the Ctrl key and click on the XP bar. Your character will declare to the party, "I'm level __ and I'm __% to my next level." If you want to let the party healer know you're in Health trouble, hold down the Ctrl key and click on your Health Bar. Perhaps you want to describe exactly which skill you are using, either on an ally or on an enemy. Again, Ctrl + command comes to the rescue—hold down Ctrl, hit the skill you want to use, and your character will declare (for example) "I'm using Resurrect on [ally's name]!"