Since you're new here I'll give you the first and best piece of advice that can help you survive. KEEP MOVING! That's right, keep moving at all times. Standing still is the quickest and easiest way to end up dead in this game.
Snipers are constantly trying to line up shots on you, so the more you move around, the greater the likelihood they'll miss. Even when you're on defense, keep moving. Patrol the area, don't stand there like you're sleeping in your armor. If you're going to snipe somebody, make sure you're in a dark place that's releatively safe, such as a high balcony or around some crates for cover.
In our training exercises I've seen far too many lunkheads on "guard duty" have a Trando calmly walk past them with the flag and capture it, sometimes even knifing the poor guy in the back before leaving. This has got to stop. TURN AROUND and see who's with you and you'll notice little things like that.
The enemy is clever and smart, you have to be smarter. Test each other to hone your skills. Movement is key!
The next bit of advice might seem a little strange, but not for combat veterans. Jump around! I don't mean be a monkey. I mean leap to your destination for extra mobility and to make a more difficult target. Perhaps you've heard of strafe running or strafe jumping. Best to learn about these things early on, as they may save your hide one day.
Whenever a soldier falls in battle, he'll drop the weapon he was carrying and whatever grenade type he had selected at the time. You can retrieve these to use yourself (and indeed you should always check after you make a kill for anything useful) of course. Keep your wits about you as you gear up though, somebody else will want that stuff and see you distracted, wishing to take advantage. So be quick!
The "use" function is utilized in the battlefield to pickup weapons (grenade pickups and Bacta tanks simply need to be run over to be collected) as well as to activate switches, which manipulate elevators and blast door shields.
Most weapons have a "reload" function. Some guns take an especially long time to load (such as the Heavy Repeater). Since you can reload on the run, find a safe place away from the enemy and reload, so you'll be ready for the next encounter. If you're attacked while reloading you can quickly do a rifle butt (and use grenades) or better yet, switch to another weapon that is ready to go so you can fight. If you survive, you'll have some time to finish that reloading job.
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