This is written assuming that you've played the battleground Strand of the Ancients (SotA) before, but perhaps haven't discovered how everything works. Unlike the regular battlegrounds, where it's rather easy to see what you need to accomplish and there are multiple methods to doing that, in SotA the best method is outlined quite clearly. It's also the only battleground to have siege engines and wall defenses. Many players have been wanting this kind of battleground since WoW was first announced, since they wanted an experience tied closely to the Warcraft RTS. Only now, with Wrath of the Lich King, has Blizzard finally implemented destructible buildings and the like.
These are the most important pieces of the new battleground. The attacking force’s entire goal is to do nothing but protect these tanks and drive them to victory. The worst thing that a tank driver can do is aim their siege abilities anywhere except for at a gate. Tanks do not deal enough damage to kill a player in a reasonable amount of time, and also their targeting mechanisms are not made to hit moving targets. The entire assault team is all about speed and efficiency. As soon as the boats land, players need to grab all four tanks and, depending on the strategy, either all attack one gate or assault both gates. All four tanks to one gate is popular because it guarantees that the gate will be destroyed. All tanks available should be filled and heading towards a gate at all times. There should never be a tank sitting at its spawn point.
Anybody can drive a tank, but certain classes are more suited to the role. Namely players that are protection spec because they can't do much else. Each tank has a secondary slot that often goes unused. This spot provides immunity to all damage, and is perfect for casters such as mages and warlocks to sit in. From these immunity perches a ranged class can decimate the defenders who are trying to destroy the tank, mages especially. If there's a bunch of melee attacking the tank, a mage can frost nova and they're all stuck far behind.
The rest of the assaulting force should be doing their best to keep the defenders from harming the tanks. Killing defenders or CC'ing them as far away as possible. There isn't too much more to tanks, just a few tips in using them:
Tanks should always travel in groups of at least two. Two tanks should not be on top of each other, rather they should be decent bit apart so that both player AoE's and Turret damage is given to both. If the path you are taking has a giant rock in between you and the gate you're trying to destroy then you should take a staggered approach: Move in a straight line towards the gate, launch a fireball, then turn the tank in a direction that will allow it to around the obstacle, and then once the fireball is ready to be fired again, aim the tank back at the gate and repeat until the obstacle is cleared. This staggered approach will allow a player to deal damage to the gate the entire time, despite possible obstacles in their path.
Defenders of course have one major goal. Protect the gates. And the best way to protect the gates from tanks is to destroy the them before they get there. Defenders should try to ignore attackers as much as possible and focus on the tanks. Some attackers need to be watched out for of course, AoE'rs can wreck defenders freely because nobody is attacking them. Tanks are a much bigger threat then a player with a seaforium charge.
Turrets can be tricky to use, and while people may not realize it, their skill at targeting does make a difference. Using the targeting reticule, defenders using turrets should lead their targets by some distance. Just how much of a lead should be given depends on how far away you're shooting, basically you have to take traveling time into account for the rockets. Defenders should not just fire aimlessly at the tanks though, they need to try and line the center of the reticule up with where the tank is going to be as much as possible. This is because turret damage is a splash effect, dealing more damage to those closer to where the rockets landed. As of right now, a rocket dead on will deal 5k damage to a tank. A rocket nearby a tank will only deal 3k damage to it, and a rocket that almost missed will only deal about 1.5k. It is integral that players in the turrets have the ability to use them to their maximum effect, otherwise they would probably be better off destroying the tanks in a more conventional manner.
Turrets are useful when used properly, but they should be the last line of defense, not the first. The first line of defense is of course the players on foot. One of the worst things a team can do in this game is wait for the attackers/tanks to come to them. There is all that ground between where the attackers/tanks spawn and where the turrets/gates are, that must be used to punish the attackers. Gates really can't take much damage, that's why when four tanks go to one gate right off the beach there's not much the defenders can do.
Attackers will sometimes find it necessary to destroy turrets, though for the most part they can be ignored as multiple tanks drive up and break down the gates. The only turrets that really need to be destroyed are the two guarding the yellow gate. Allowing them to keep shooting at your fresh tanks is a great way to never destroy the keep.
Massive Seaforium Charges
There should never be an assaulter not carrying one of these, especially since they're stacked up so nicely right next to where the tanks spawn. Dropping one at the foot of a gate is instant, and almost as good as a cannon shot from a tank. Massive Seaforium is most important when assaulting the keep at the end of the match, because it is the door with the lowest health out of all of them, and also the one least likely to ever get hit by a tank because it is so far away from the tank spawns.
For defenders, ideally they will never allow anyone close enough to lay one of these. But with tanks pounding towards the gates that's a slim reality. Since it takes time to disarm a Massive Seaforium Charge after it's been laid, the best options are to kill or CC the assaulter as fast as you can so he won't interrupt you, and then try and disarm it. You only have around 8 seconds before the charge goes off, so not much time to do anything.
A boon for the attackers, and a ridiculous annoyance for the defenders, is that a broken down tank does not despawn. Much like the skeletons of players, the "dead bodies" of the tanks remain in heaps, and make clicking anything underneath them near impossible. If there is a broken down tank at a gate, defenders have little chance to disarm the seaforium charges because they will not be able to click on them.
For some reason, a lot of SotA matches that I'm in, players either don't assault graveyards, or nobody defends them. Graveyards are incredibly important to winning a SotA match. Initially, there are four tank spawn points, and they are all down at the beach. Once a graveyard is captured, the Engineering shop "opens" and it will spawn 2 more tanks. Unlike the tanks down by the beaches, these tanks are right there next to the new gates that need to be destroyed.
For defenders, graveyards are the most important thing except for the gates. If the defenders can prevent their graveyards from being taken then they gain a major advantage as the attackers have a lot of ground to cover in their tanks before they're able to hit the new gates. It's rather unfair really, the defenders have such a large advantage. Turrets from the 2nd row of gates can reach the graveyards, essentially preventing them from ever being captured. If the attackers neither destroy the 2nd gate or take the graveyard on their first attempt they could be stuck breaking on the defense endlessly.
Now that all the basics are covered, there's a step by step strategy in winning any SotA match. The boats have just landed.