Choosing the right weapon is a crucial part of game strategy. Different maps may not have every weapon available, so it's important to know the map you're playing on, in order to adjust your strategy as needed. Here's a breakdown of all of the different weapons in the game, and when you might want to use them.
The saber can be a powerful weapon when used correctly. It's virtually useless in ranged combat compared to guns, except as a shield. However, it can be invaluable to take down an opponent at close range, when you can deal damage with it. Avoid the special kata moves that lock you into a fixed position, as these are really easy for enemy players to dodge - the only exception is if you're guarding a stationary object, like if you do one while standing on the flag stand (though even this seldom works). Learn to move so that your blade stays mostly in front of you when swinging, and you can use it to take out an enemy who's low on speed (or just slow). Be mindful that if they can, the enemy will drop out of saber range as quickly as possible though, and counterattack with a powerful gun.
Rocket Launcher (Merr-Sonn PLX-2M Portable Missile System)
The rocket launcher is the most generally useful gun in the game. Its missiles travel in a straight line when you fire them, and will explode on impact with anything. The explosion will deal more damage the closer the enemy is to it, so the best strategy is to aim at the enemy, but in such a way that if you miss, there will at least be a wall or floor that you hit instead which will still deal them some damage. If you are confident in your aim, you can also go for mid-air shots (which look cool in highlight videos), but make sure you have enough ammo to take them out on the ground if you miss. The most common defense to being shot at by rockets is for the enemy to use force protect (in which case, pull their weapons away from them or pull them into a pit, since they can't activate both protect and absorb at the same time). Another common defense is to try to pull your gun away from you, so be sure to use absorb if you think they have more than 20 force points.
Imperial Heavy Repeater
The repeater's primary fire sends a somewhat randomized spray of tiny bullets toward your target, which can be useful at close range, but only if the target doesn't have their saber up. (The bullets can be completely blocked by the automatic saber defense). The more useful mode is the alt-fire, which fires a blue blob. Similarly to the rocket launcher, the blob deals splash damage on impact. However, unlike the rocket launcher, the blob is affected by gravity, instead of travelling in a straight line, so aiming it is rather different (and easier in some situations). It deals less damage than a rocket would, but you also get more shots out of the gun on pick-up than you do from the rocket launcher.
Golan Arms FC1 Flechette Weapon
The golan's primary fire is a burst of small particles that can deal a fair bit of damage to the target. It can be useful for finishing off a target once you get their health points (HP) low. It also has a useful secondary fire mode, which fires two explosive balls at a target. Unlike its primary fire mode, the balls are affected by gravity, and bounce on walls and the floor. They will explode if they come into contact with a player, or after a certain amount of time, whichever happens first. The balls' initial trajectory is a bit random, so it's easiest to get them to hit at close range.
DL-44 Heavy Blaster Pistol
The pistol is the only gun which you always have, and it has infinite ammo. The primary fire mode is pretty useless, since it deals little damage and can be blocked easily by a saber. The secondary fire mode can also be blocked, but just 2 or 3 fully-charged hits will kill a player at full HP. Since it can be blocked, it's most effective when the target is looking away from you (shoot them in the back, away from their saber). It's also possible to hit from the front, but much harder - the rear foot is vulnerable since the saber doesn't block shots at it.
Tenloss DXR-6 Disrupter Rifle
The tenloss (also known as the sniper rifle) is the best weapon for long range combat, since there's no delay between firing a shot and it hitting the target. Basically, you can just point it at your target, and if you've got them right in the middle of your screen, then the shot will hit them instantly. The primary fire mode can be used to deal some damage at a distance, though the amount of damage is relatively small. The secondary fire mode allows you to charge the shot before firing, which deals much more damage (a player can be taken out by a single well-aimed head shot). However, it requires you to remain in one spot while the shot is charging, during which time the target may be able to move behind a wall or otherwise out of your line of sight, requiring you to reposition yourself and restart the charging process.
Det packs are useful in a few scenarios. You can lay them on your flag stand, and when an enemy approaches to take the flag, blow them up (2 is enough to take out an enemy if they're right on top of them). You can also fire one and immediately self-kill when you are right next to an enemy, which will deal them a lot of damage as it will instantly explode, kamikaze-style. However, you too will die, so if you do this to an enemy flag carrier in their base, it's likely they will get back to the flag before you can. Finally, they can be used by a flag carrier running away by planting them as they run, and then exploding them a split second later to discourage would-be chasers from following them too closely.
Thermals are useful since they deal splash damage and can directly hit a player even with their saber up. To use one, you first charge it by holding down the fire key, and fire it by releasing the key. The longer you charge it, the more force you will fire it with. Thermals are affected by gravity. In primary fire mode, a thermal will bounce around off all walls and floor until a certain amount of time passes, at which point it detonates, dealing splash damage to anyone near it - unless it happens to hit a player first, in which case it detonates immediately. In secondary fire mode, instead of bouncing, any impact will cause the thermal to immediately detonate. Usually the secondary fire mode is more useful, since it uses the same amount of ammo but deals the damage quicker and doesn't leave time for players to run away from it.
The blaster rifle is pretty useless in most cases since a player with their saber up will block virtually all shots. In primary fire mode, it fires at a slow rate a single straight shot, which deals a small amount of damage if it hits the target. In secondary fire mode, it rapidly fires the same type of shots, but their direction is a bit randomized, so it is even harder to hit the enemy (making your accuracy about as bad as the stormtroopers in the movies!)
The bowcaster is slightly better than the blaster rifle. In primary fire mode, you can charge each shot by holding down fire. When you shoot, there will be multiple shots fired out in an arc, and the longer you charge, the more shots are fired. This mode can be lethal at close range, if you can get many of the shots to hit simultaneously, although this can be thwarted by the player having their saber up. In alt fire mode, the shot bounces off of walls, which can lead to some funny hits, though it is very difficult to aim consistently off a wall.
Demp (Electromagnetic Gun)
The demp is a useful gun for dealing out damage to the enemy while staying a safe distance away. In alt fire mode, firing the demp will generate an expanding field of electricity, which does more damage the closer the affected players are to its origin. The field can be charged for greater range by holding down fire before releasing it. Additionally, affected players will sometimes be prevented from firing any weapon of their own, or using force, for a short period of time. Flag carriers can use this to their advantage by spamming alt bursts while running away, since the enemy chase will run into them and be prevented from dealing damage. The primary fire mode fires a weak projectile version which is not affected by gravity. If you hit an enemy player with it, it will have the same effect as the field version (prevents them from shooting their own gun and using force for a short time) as well as deal a small amount of damage.
Stouker Concussion Rifle
The concussion rifle (conc) is a powerful gun, but uses a big chunk of ammo. By default, when you pick one up you only get a single shot, without picking up any additional ammo packs. The primary fire mode fires a powerful energy shot which deals splash damage, and is not affected by gravity. The secondary fire mode fires an instant beam which will knock down any player it hits who is close to you. If the player is too far away, it will do just a small amount of damage and mildly change their angle of velocity.