The Priority Beacon is an end-game structure that can only be built on a specific yellow block in the middle of the Mainland. It is a weapon that activates continual Orbital Bombardment by Laser Strikes. It is the most powerful, however most expensive weapon in the game.
The Priority Beacon is the most expensive structure in the game, costing 25000 units of Iridium, or roughly the equivalent of 22.7 Large Tanks. Constructing the Beacon will require several minutes of work by a Fabricator, but more Fabricators can be built to speed up the process. The Beacon can only be build on the Gold Well Pipe in the center of the map. Once completed, it has the appearance of a tall antenna with a small base, with some parts the color of the team that build the Beacon. The Beacon has very low health and should be protected by whoever built it.
If you are on the team building the Priority Beacon, it is recommended that you first build heavy defenses around the Beacon before actually building the Beacon. This probably includes Walls, Point Defenses, lots of Turrets and Arc Turrets, several Shield Generators and other defenses. You will then have to defend in this fortress for 2 and a half minutes until the Orbital Bombardment starts. You can use fabricators to build it automatically. However, you have to get some well pumps and conseders, otherwise the Iridium supply will be wasted. Having your Beacon destroyed will result in you having to build it again, a very time and Iridium-consuming process.
Upon completion of its construction, a countdown of 150 seconds will begin, with a warning in the chat every 15 seconds notifying all players of time remaining. At the end of the countdown, Orbital Bombardment will begin, which is extremely destructive to enemy teams and is able to wipe out even the most fortified bases. This bombardment will continue as long as there are still enemy structures remaining and the Beacon is not destroyed.
Orbital Bombardment is initiated when the Beacon is finished and the countdown ends. The Orbital Bombardment consists of a constant barrage of Laser Strike-like lasers at structures not owned by the team that initiated the Bombardment.
The lasers all originate from above and at random angles. They may have trouble damaging structures located underground or at Sea Bases, and will instead damage the terrain above them first, or may even strike the structures of the team that built the beacon if an enemy structure is beneath them. The random angles may also cause the lasers to damage Spires if enemy structures are close to them. The Lasers Strikes do not directly target players.
Unlike with the standard Laser Strike, Shield Generators will NOT block the lasers from the Orbital Bombardment. The lasers strike in rapid succession and won't stop until all enemy structures are destroyed; because of this, Orbital Bombardment is abnormally powerful and can annihilate even the most fortified bases.
As mentioned before, Shield Generators will not block lasers from the Orbital Bombardment, making physical barriers, such as terrain or Walls the best shields available. However, due to the power of the lasers, even these barriers won't last longer than a minute. This being said, Skybases are most vulnerable to the Orbital Bombardment, while Sea Bases are the most protected.
It may be a good idea to sneak up on your enemy's base if you know they are building a Priority Beacon and build many small, cheap structures, such as Light Sources, so when Orbital Bombardment does begin, it will attempt to hit those structures, destroying the base above in the process. However, this does not work if you tried placing said things near the Beacon, the lasers do not target anything in the Beacon's proximity to avoid it getting blown up by incident.
Because of this, it is very important to disable the beacon as soon as possible. Thankfully, the Beacon has a very low amount of health, and repairing it will require a percentage of Iridium equal to how much Iridium it costs; repairing 66% takes 16500, more than ten times the cost of the Point Defense, currently the second most expensive structure. A partially complete blueprint takes a substantial amount of time to destroy, requiring several minutes of Laser Drilling to destroy. It may be better to allow the Beacon to complete building before attempting to destroy it. If the Beacon is unguarded but almost finished, place down a couple Satchel Charges under the block near it, so when it finishes you can quickly blow it up. Using a Laser Drill is a good idea, as it will effortlessly and quickly destroy the Beacon in just a few hits.