Gauss Cannon

The Gauss Cannon is the heavy gun of the middle game. It fires for 1,100, which is more than four times a Pulse Cannon and about a third of a Plasma Cannon, and it is the cheapest gun in the game that an Ares Class Bomber cannot rapid fire. You build it on the Defense page and it stays on that planet for good.

What one shot does

A shot takes the target's shield off first and whatever is left goes into the hull. Shields refill at the start of every round, hull damage does not. On top of that, any unit that has lost more than 30 percent of its hull can blow up at the end of a round it was hit in, and the chance is the same as the share of hull it has lost.

So one Gauss hit, at base stats before any research, does this:

Target	Hull	Damage from one hit	Result
Artemis, Apollo, Atlas, Zagreus, Hermes, Helios, Genesis	100 to 850	more than the hull	dead outright
Hercules Cargo	1,200	1,075	blows up about 9 times in 10
Dionysus Recycler	1,600	1,090	about 7 in 10
Poseidon Cruiser	2,700	1,050	about 4 in 10
Gaia Colony Ship	3,000	1,000	about 1 in 3
Carmanor Cargo	3,600	1,000	survives, 28 percent is under the line
Athena Battleship	6,000	900	survives
Hades Battleship	7,000	700	survives
Ares Bomber	7,500	600	survives
Prometheus Destroyer	11,000	600	survives
Zeus Class	900,000	none	1,100 does not get past 50,000 shield

The Poseidon line is the one the game's own Advantages note is talking about. It is a real 4 in 10, not a rounding error, and it is why a handful of Gauss Cannons ruins a cruiser raid.

There is one target it cannot touch at all. A shot worth 1 percent or less of the target's full shield bounces off for nothing, and a deployed Hephaestus platform carries 150,000 shield. A base Gauss Cannon needs Weapons Tech 4 before its shots even register against one, and even then they only chip the shield.

The one thing that rapid fires it

The Zeus Class has rapid fire x50 against the Gauss Cannon and nothing else in the game does. Rapid fire means the Zeus gets to shoot again after it kills one, and at x50 it keeps going 49 times out of 50, so a single Zeus strips roughly fifty cannons a round without any help. Nothing at all rapid fires the Plasma Cannon, which is the trade the More Info panel is pointing at.

Here is what that costs, one Zeus against a wall of one type, matching research on both sides, averaged over 150 runs of the live battle engine.

Wall	What it cost to build	Zeus dies	Cannons lost
200 Gauss Cannon	7,400,000	76%	122
300 Gauss Cannon	11,100,000	99%	85
35 Plasma Cannon	4,550,000	36%	6
50 Plasma Cannon	6,500,000	90%	4

Read the last column. The Plasma wall kills the Zeus for a bit over half the money and loses four cannons doing it, while the Gauss wall pays for the same kill with eighty-five. If a Zeus is the thing you are worried about, the Gauss Cannon is not the answer.

What it is actually for

The Ares Class Bomber is what people bring to knock a wall down, and it has rapid fire against every defense cheaper than the Gauss: Missile Battery x20, Laser Cannon x20, Pulse Cannon x10, Particle Cannon x10. Against a Gauss Cannon it fires once and stops.

Here is two million resources of wall, one defense at a time, against 40 Ares Bombers with matching research on both sides. Averages over 120 runs.

Wall	Ares killed of 40	Wall lost	Planet falls
1,000 Missile Battery	3.9	all 1,000	every time
1,000 Laser Cannon	16.9	all 1,000	every time
250 Pulse Cannon	1.1	all 250	every time
250 Particle Cannon	0	all 250	every time
54 Gauss Cannon	33	47 of 54	10 percent of runs
15 Plasma Cannon	15.4	all 15	every time

Same money, and the Gauss wall is the only one on the list that usually beats the raid off. It is not close either: it kills five sixths of the bombers where the next best wall kills two fifths.

That is one run of the same fight in the in-game Calculator. Forty Ares against fifty-four Gauss Cannons ends as a draw at round six, the raid goes home thirty bombers down, and the Plundered row is empty. The 675,000 debris on the board is all from the attacker's own wrecks, because defenses leave none.

The line moves fast with the size of the raid, though. Same 54 cannons:

Ares in the raid	Ares killed	Gauss lost	Planet falls
20	all 20	5	never
30	all 30	19	never
40	33	47	10 percent of runs
50	17	all 54	every time
80	4	all 54	every time

Anything up to about forty bombers dies on the wall. Fifty walks straight through it. That is what a wall is in SFC2: not a shield, a price, and it stops the people who turn up with just barely enough.

Against other fleets

The Gauss is a gun, not a body, and that limits where it shines. Against 100 Athena Battleships the same 54 cannons kill 9.9 and die to the last one, which is exactly what 15 Plasma Cannons do for the same money. Against 150 Poseidon Cruisers they kill 58 before they go. Against 40 Prometheus Destroyers they kill 4 and the planet falls, while two million resources of Missile Battery beats that same raid off outright.

Cheap cannons are bought for their bodies. There are so many of them that a raid cannot clear the planet inside six rounds, and an attacker who does not clear it gets no plunder at all. The Gauss is bought to make the attacker pay in ships. A wall that does both beats either on its own, and the Decoy and Large Decoy sit on top as extra bodies that nothing rapid fires.

Where you build it

Defense page, same as the rest of your defenses. The planet needs a Shipyard at level 6, plus Weapons Tech 3, Energy Tech 6 and Shield Tech 1. A Shipyard cannot be built on a moon, so a moon never carries Gauss Cannons.

The row shows Base next to Current so you can see what your research has done to it. Every level of Weapons Tech adds 110 attack, every level of Shield Tech adds 20 shield and every level of Armor Tech adds 350 hull. None of it compounds, it all works off the base number. The planet above is on Weapons, Shield and Armor 10, which is why 1,100 reads 2,200 and 3,500 reads 7,000.

Build time counts ore and crystal only, so the Gauss is 35,000 build resources:

Time (hours) = 35,000 ÷ (5,000 × (Shipyard level + 1) × 2^{Foundry level})

That is one hour each on a bare Shipyard 6, and it drops fast. The planet in the shot is Shipyard 9 with a level 4 Foundry, so it turns one out every 2 minutes 38 seconds. Ships and defenses share one build queue per planet, you cannot cancel anything once it is in that queue, and you cannot start either while the Shipyard or the Foundry on that planet is upgrading.

There is no way to take a Gauss Cannon back down again. Deconstruct only exists for missiles.

After the battle

Defenses leave no debris, and about 70 percent of everything of yours that was destroyed is rebuilt free the moment the battle ends. The battle report lists it under Regeneration. So the 47 cannons that wall lost against the bombers are really about 14 gone for good, a bit over 500,000 resources, against the 2.7 million of Ares the raider wrote off. That is the whole argument for a wall.

The rebuild only covers fleet battles. Defenses killed by an Interplanetary Ballistic Missile are gone permanently, and a Gauss Cannon is a fat target for one.

Cost

Ore	Crystal	Hydrogen
20,000	15,000	2,000

Stats

Attack	Shield	Hull
1,100	200	3,500

Requirements

Shipyard (level 6)
Weapons Tech (level 3)
Energy Tech (level 6)
Shield Tech (level 1)