Combat

Combat happens when an attack fleet reaches its target. Everything the attacker sent fires at everything the defender has on the field: the ships parked on the planet, the defences built there, and any allied Group Defend fleets sitting on it. If the attacker clears the field and still has cargo space left, the attacker plunders the planet.

Only ships, defences and the resources sitting on the planet are at risk. Buildings, research and anything in a build queue are never touched by a battle, and most of the defences that die are rebuilt for free straight afterwards.

An Attack is the only mission that starts a battle. Transport, Harvest, Deploy and the rest never fight. Espionage probes can be shot down by counterespionage, but that is a separate roll and not one of the rounds below. Missile strikes hit defences directly and have their own rules.

How it works

A battle runs for at most six rounds. It stops early the moment one side has nothing left on the field.

In each round, every unit that is alive at the start of the round fires once. Each shot picks its target at random from everything the other side still has, ships and defences together. Nothing aims for the expensive targets, and that is the whole reason a screen of cheap fodder works: every shot that lands on an Artemis is a shot that did not land on your Athena.

Units are not removed until the round is finished, so a ship that is shot to pieces still gets its own shot off in the round it dies.

If a shot hits something the shooter has rapid fire against, the shooter immediately gets a chance at another shot, at a fresh random target. With a rating of N the chance of that extra shot is (N - 1) / N, so x5 is 80 percent and x200 is 99.5 percent. The chain keeps going until a roll fails or a shot lands on something the shooter has no rapid fire against. A shot that is absorbed by a shield, as described further down, also ends the chain.

Weapons

The damage of a single shot is the shooting unit's Weapons Rating. An Artemis Class Fighter has a Weapons Rating of 50, so when it hits an Atlas Class Cargo it does 50 damage.

Weapons Tech adds 10 percent of the base rating per level and it does not compound. At Weapons Tech 9 that same Artemis hits for 50 x 1.9 = 95. Shield Tech and Armor Tech do exactly the same thing for Shield Rating and Hull Rating.

Shield and hull

Damage hits the shield first and whatever is left over comes off the hull. An Atlas Class Cargo has a Shield Rating of 10 and a Hull Rating of 400. Shot by an Artemis for 50, the shield eats 10 and the remaining 40 drops the hull to 360.

Shields refill in full at the start of every round. Hull damage does not repair, and nothing repairs mid battle. So in round two that Atlas has its 10 shield back but only 360 hull, and it ends round two on 320.

Shots that do nothing

A shot is absorbed completely, for zero damage, when it is worth 1 percent or less of the target's Shield Rating. The comparison always uses the target's full Shield Rating, not whatever is left of the shield that round.

An example. You have Weapons Tech 12 and you attack a player with Shield Tech 9. One of your Artemis fires at a Large Decoy.

Your Artemis hits for 50 x 2.2 = 110.
Their Large Decoy has a shield of 10,000 x 1.9 = 19,000.
1 percent of 19,000 is 190. 110 is under that, so the shot does nothing.

Because Weapons Tech and Shield Tech both add the same 10 percent a level, research almost never changes the answer. An Artemis will never damage a Large Decoy no matter how far you push Weapons Tech.

Here is the whole rule in one table, using base ratings. Only targets with a shield of 100 or more can absorb anything at all.

Target	Base shield	Shot must beat	What bounces off it
Hephaestus Class Attack Platform	150,000	1,500	Everything except the Prometheus, the Plasma Cannon and the Zeus
Zeus Class	50,000	500	Everything up to and including the Poseidon at 400. The Hades at 700 and anything bigger gets through
Large Decoy	10,000	100	Everything up to the Missile Battery at 80. The Laser Cannon at 100 is on the line
Decoy	2,000	20	The Carmanor at 10, the Atlas and Hercules at 5, and the recyclers and satellites at 1
Prometheus, Ares, Particle Cannon	500	5	The recyclers and satellites at 1. The Atlas and Hercules at 5 are on the line
Hades Class Battleship	400	4	The recyclers and satellites at 1
Plasma Cannon	300	3	The recyclers and satellites at 1
Athena, Gauss Cannon	200	2	The recyclers and satellites at 1
Gaia, Carmanor, Pulse Cannon	100	1	The recyclers and satellites at 1 are on the line
Everything else	50 or less	under 1	Nothing

Where the table says "on the line", the shot lands only if your Weapons Tech is higher than their Shield Tech. Equal research, or lower, and it bounces.

"The recyclers and satellites at 1" means the Zagreus, the Dionysus, the Helios Class Solar Satellite and the Genesis Solar Satellite. All four have a Weapons Rating of 1 and are close to useless in a fight.

Five units have a Weapons Rating of 0 and never damage anything at all: the Hephaestus Class Attack Platform, the Decoy, the Large Decoy, the Hermes Class Probe and the Shadow Probe. They are there to soak shots, not to shoot back.

Going the other way, three things are effective against every unit in the game: the Prometheus Class Destroyer at 2,000, the Plasma Cannon at 3,000 and the Zeus Class at 200,000.

Anti-Ballistic Missiles and Interplanetary Ballistic Missiles take no part in a fleet battle at all. They only ever fire at missiles.

Units blowing up

At the end of each round, every unit that took hull damage in that round rolls to see if it survives. The chance of being destroyed is the share of its Hull Rating it has lost over the whole battle so far. Below 30 percent lost there is no roll, and a unit on zero hull is gone for certain.

Take that Atlas being hit by one Artemis every round. It loses 40 hull a round out of 400.

End of round	Hull left	Hull lost	Chance of being destroyed
1	360	10%	No roll
2	320	20%	No roll
3	280	30%	No roll
4	240	40%	40%
5	200	50%	50%
6	160	60%	60%

So one Artemis firing for the full six rounds still has a decent chance of failing to kill one Atlas. Weight of numbers decides battles here far more than any single ship's stat line.

Who wins

Attacker wins when the defender has nothing left on the field and the attacker still has ships. The attacker plunders.
Defender wins when every attacking ship is destroyed and the defender still has something left.
Draw when both sides still have units after six rounds, or when both sides are wiped out. No plunder either way.

There is one exception. A surviving Hephaestus Class Attack Platform is not counted on the defender's side. Its hull is 4,000,000 and its Weapons Rating is 0, so if it counted, nothing could ever be plundered off a planet with one parked on it. The attacker wins and takes the loot, and the Hephaestus survives.

What the report looks like

Both players get a Battle Report in their inbox. The top of it names the two sides, the winner and how many rounds it ran, then lists what you lost.

Under that come the payoff numbers: what you carried away, the Destroyed Ships Points both sides earned, and the debris left floating over the planet.

"Show full report" opens the rest: both starting rosters, the defender's losses in full, the moon roll and the defences that regenerated. The report is a summary of the outcome, not a round by round log.

Plunder

The winner takes 50 percent of the ore, crystal and hydrogen sitting on the planet when the battle ends. That goes up to 55 percent if every attacking fleet belongs to an alliance at war with the defender and no third party is helping defend. A Resource Den protects its capacity off the top before any of that is worked out.

You can only carry away what your surviving cargo space holds, and the game fills your holds evenly across the three resources instead of loading up on ore first. In a group attack the loot is split between the participants by surviving cargo capacity. See Plunder for the detail.

Debris

30 percent of the ore and crystal build cost of every ship destroyed, on both sides, is dumped into the debris field over the planet. Two things catch people out:

Defences leave nothing. Blowing up a wall of turrets creates zero debris.
Hydrogen never becomes debris. Only ore and crystal.

In the battle above, the ships the two sides lost were worth 1,416,000 ore and 690,500 crystal, and the debris field is exactly 30 percent of that: 424,800 and 207,150. The 600,000 worth of Pulse and Laser Cannons that also died added nothing at all.

Defences come back

Straight after the battle, 70 percent of the destroyed defences are rebuilt for free on the defender's planet. Genesis Solar Satellites come back the same way. It is a roll per unit, so the exact count moves around a little.

In that report 60 Laser Cannons and 60 Pulse Cannons died, and 40 and 43 of them were back before the attacker got home. Put that together with defences leaving no debris and it is clear why smashing a defence wall never pays for itself. The only thing worth taking off a well defended planet is what is behind the wall.

Moons

Any battle that creates debris also rolls for a moon at the target. The chance is that battle's total debris divided by 15,000,000, capped at 20 percent, and anything under 1 percent does not roll at all. The report prints the number either way, as in the shot above.

Destroyed Ships Points

Both sides earn DSP for the enemy ships they destroy. Defences are worth nothing.

A ship is worth its full build cost, ore plus crystal plus hydrogen, divided by 1,000 and rounded down. An Apollo Class Fighter costs 6,000 ore and 2,500 crystal, so it is 8 points and not 8.5. Multiply by the number destroyed and add it up.

Two adjustments:

Attacking an NPC pays the attacker half DSP. The NPC side is not reduced.
In a group attack the total is split between the attackers in proportion to the value of the fleet each one committed.

DSP counts towards your overall rank on the Leaders board.

The report above shows 1,540 for the attacker and 568 for the defender. The 1,540 is the 20 Dionysus at 18 points each, 20 Hercules at 12, 70 Apollo at 8, 20 Atlas at 4, 70 Artemis at 4 and 20 Hermes at 1. The 120 turrets that also died added nothing.

Group attacks and group defends

Up to seven fleets can join one group attack, and up to six fleets can sit on a planet as group defenders. Everything merges into a single battle: one roster a side, one set of six rounds, one report. Losses, plunder and DSP are then split back out per player afterwards.

Alliances that have bought the Repair Dock perk get some of those ships back. When a member defends their own planet, 10 percent of their destroyed ships per perk level is banked, up to 70 percent, and it sits on the Overview and Shipyard pages waiting to be claimed for seven days.

Try it in the Calculator

The Calculator page runs the same battle engine the game does, so you can price an attack before you send it. Put in your fleet and your research, put in what you think the defender has, and press Simulate.

That is the same fight as the report above. It called the same winner, the same six rounds, the same 1,540 and 568 DSP, and landed within 150 crystal on the debris. The Calculator runs the fight three times and shows you the worst of the three, so it reads a little pessimistic on purpose. The real battle only rolls once.

Very large battles

Once a battle has more than three million units on the field, the game stops tracking every individual hull and works the result out statistically instead. The rules are the same: six rounds, the same 1 percent absorb line, the same 30 percent destruction threshold. In practice you only meet this on the biggest NPC stacks.