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Using the mouse is easy since it comes down to pointing and shooting like in many other games. Most people get tripped up a little with movement. The "W," "A," "S," and "D" keys control your movement by default. "W" and "D" let you move forward and backward. "A" and "D" allow you to strafe, or move from side to side. In Counter-Strike, you do not need to move forward or backward to strafe. That means that, if you're standing still, pressing the "A" and "D" buttons is all you need to move to the left and right, respectively. Moving, turning, and shooting requires coordination. It may feel a little tricky at first, but you get used to it as you play. Test your mouse sensitivity. Most pros access the settings menu to move the sensitivity slider down to 2.0, giving themselves more precision when aiming. Start low and increase the sensitivity as you play. Running everywhere is a sure way to alert enemies to your presence. Hit the "Shift" key to slow your character down, then hit it again to return to running. Press "CTRL" to duck and the spacebar to jump. These keys are important to remember for map navigation. Mix some stealthy maneuvers into your playstyle to get the drop on enemies and reduce the amount of damage you take. You are only allowed to carry 2 weapons at a time in Counter-Strike. The left mouse button fires whatever weapon you are holding. The right mouse button activates the weapon's secondary function, such as zooming in with a sniper scope. It's a very simple shooting scheme that anyone can figure out with a few rounds of practice. Press "Q" to switch between your primary and secondary weapon. The "R" button allows you to reload your weapon. Do this before you enter a firefight. You mainly switch weapons by purchasing them at the start of the round, but the game lets you take weapons you find by pressing "G." Counter-Strike's unique feature is its weapon economy. When you enter a game, you get $800. That money allows you to buy guns, grenades, and armor from the menu. The menu gives you a lot of toys to play with, so it may feel a little intimidating at first, but don't feel pressured to buy anything. Navigate the menu by clicking the prompts are using keypad numbers. You start with a pistol and a knife, so you don't need to spend your in-game currency right away. Buying weapons and armor is all up to your preferred strategy. Some players get armor and grenades right away, while others save for a submachine gun. Communication is a key part of Counter-Strike, so press "K" when you need to activate voice chat. This only works if you have a microphone on your computer. For text chat, press "U" to call up the dialogue box, then type your message and hit enter to send it to your team. Pressing "Y" allows you to send a message to the entire server. Don't use this command while strategizing with your team. The game also has pre-recorded commands activated by typing words into the chat box. For instance, type "coverme" to make your character say "Cover Me!" Few players pay much attention to these commands, so they aren't important to memorize.

Summary:
Use your keypad to move and your mouse to aim. Master the jump, duck, and walk controls to avoid enemies. Press the mouse buttons to fire your primary and secondary weapons. Press "B" to bring up the gun menu when you begin playing. Press "K" or "U" to communicate with your team throughout the match.