Double Damage
The purple item near node 3 at the center of the map doubles the damage you inflict with every shot of every gun and every vehicle. However, it does not double the speed at which you link up nodes. All too often people get the DD as soon as they reach node 3 and then stand there linking the node wasting the DD. Instead of getting the DD as soon as you reach node 3, wait until you have node 3 completely built and then get the DD. Immediately after getting the DD, hop into whatever vehicle is the fastest that you have near you and go straight to node 2 and destroy it using the DD, which significantly decreases the time it takes to destroy the node. This decreases Red's chance of taking down node 3 before you can successfully take down node 2.
This is the ideal way of using the DD. It is unlikely to be executed if you are playing against a team with any skill and knowledge of the game at all. The ideal way assumes that you won't be encountered by any enemies as you link node 3. If you are encountered by enemies, then here are a few scenarios you must take into account.
1) They attack the node you are building from a vehicle at a distance:
Get the weapon locker and use the Avril to shoot them down. Do not get the DD.
2) The enemy is shooting at the node from a distance on foot:
Shoot them down with shock or lightning or the Hellbender. Do not get the DD.
3) The enemy is nearing the double damage:
Immediately get the DD as soon as you see the enemy getting close to it. You don't want it falling into their hands because they can then easily kill you and take out node 3.
Unless you absolutely have to get the DD to keep the enemy from getting it, save it until you are able to attack node 2. If you still have some DD time left over after taking down node 2, proceed immediately to node 3 and use the rest.
Enemy Vehicles
When you have time (even in some cases if you don't), it is good to weaken the enemy vehicles. Destroying the vehicles does nothing but make the enemy wait a few seconds longer to get the ride they desire. If the vehicles are weakened until you see flames rising from them, then that will allow you to take them out with either one Avril or a couple shots of any other gun. This is extremely inconvenient for them because either they sit there and waste time and link ammo healing it or they take their chances and you are able to gun them down; hopefully the latter is what they will choose.
The best vehicle to do the job is the Raptor. With the Raptor, all you have to do is shoot the enemy Raptors and Mantas with one air-to-air missile and use the plasma shots to weaken the Hellbender and Goliath until you see flames. As soon as the vehicle begins smoking, slow your firing pace so that you don't over-shoot and destroy the vehicle.
This tactic is crucial if you have lost all your nodes in Torlan, and are trying to make a comeback. The enemies' two tanks respawn quickly and will overwhelm your 1st node unless you weaken them constantly.
Defeating Vehicles on Foot
Manta - A primary Shock blast will slow a Manta, and a secondary shot will completely stop it, letting you finish it off easily. If a Manta is trying to run you over, fire a few Shock Balls in a spread around yourself. Stick with Avrils at medium or long range.
Raptor - Avrils also work best here. Primary Shock will push the Raptor slightly, throwing off it's aim, otherwise use Lightning or secondary Minigun, which are both slow but steady.
Goliath - If you can get right next to it, circle around while shooting secondary Flak. From farther away, try to get partial cover, such as a locked node, a turret, or a tree. Shoot away with Avrils.
Hellbender - Best attacked from far away, as the shock combos will destroy you from close. Dodge around while shooting Rockets, which will shake the Hellbender and spoil its aim.
Scorpion - Easy to avoid by dodging; use Rockets or Flak to quickly destroy it.
Link Gun Management
At the start of Torlan (this is assuming you are on your own, which you shouldn't be if you follow this guide, but this may become useful in public servers), you will get 70 charges of the link gun when you pick up the weapon lockers in the base. No matter how many lockers you pick up, if the first locker you pick up gives you 70 link charges no other locker will give you more than a total of 70. Knowing this, when you get to the first node to link it, do not immediately pick up the weapon locker. This is for two reasons. The first reason is because it takes more than 70 link charges to build a node by yourself, so picking up the weapon locker and getting no extra link charges will not help you. The second reason is because since nodes build themselves, you should use all 70 charges, then pick up the weapon locker and then proceed to the next node. By the time you get to the next node, the first node will have built itself so that now you saved time by letting it build while you were getting to the next node. You can keep doing this until the other team is linked to a node that you are building. In this case, you need to build the node all the way. This is because if you let the node build the rest of the way on its own, then someone can sneak in behind you and begin to attack it before it is able to finish building. Then you can't attack their linking node while they are already there attacking yours.
Another important Link Gun tip is to throw away your Link Gun using the backslash key. Doing so will cause you to receive 130 Link at every weapons locker, instead of the usual 70. So when building nodes, use all your Link ammo but 2-4 charges, then throw away your gun and touch the Ammo Locker to get 130 more. This way, you always have enough ammo to fully build any node at any time.
Best Weapons to Destroy Nodes and the Core
The fastest way to destroy enemy nodes is by using the Manta or the Flak Cannon's secondary fire (14 shots.) Both methods take 13 seconds to destroy a complete node. The second fastest way is to use the Raptor or Goliath, which take 15 seconds. If you don't have these weapons, the Link Gun, Spider Mines, Rocket Launcher, and Shock Rifle's Combo all do a fairly good job of destroying nodes. Under no circumstances should you use the Minigun or Assault Rifle, which both do next to nothing.
The fastest way to destroy the core is with the Manta. The second fastest way is with the Flak Cannon's primary fire. With 15 shots, the Flak Cannon's primary fire will take 39 points of health from the core. The third fastest is the Raptor. The fourth fastest is with the Flak Cannon's secondary fire. With 15 shots, the Flak Cannon's secondary fire will take 30 points of health from the core.
Another thing to know is that the Flak Cannon's primary fire is stronger than its secondary fire when being used on the core and vice-versa on a node.
Of course, if you have superweapons, those work the best. A Leviathan can destroy a node in 1 shot, or the core in 2. A simgle redeemer will destroy a node - do not waste it on a tank or other enemy. Redeemers also do 30 damage to the core.