FleetCoordinationSystem (FCS)

Overview

Fleet Coordination System (FCS) lets an alliance officer open an outgoing attack so allies can attach their own fleets to the same target. When every fleet in the group has reached the target, they fight one combined battle against the defender.

In the fleet UI this appears as:

Solo attack — standard attack, no allies can join
Open to alliance — coordinated attack rally

FCS is attack-only. Same-alliance members can always join an open rally. Members of an allied alliance can join only when the lead fleet has Allow inter-alliance participation enabled.

Starting a Coordinated Attack

Who can open a rally

Only alliance officer, deputy, or leader can start an FCS rally. Regular members can join, but cannot open one.

The feature must also be active for that player (FCS feature access).

At launch

When launching an attack, the leader can:

Toggle Open to alliance to make the fleet joinable.
Optionally enable Allow inter-alliance participation (allied alliances may join).
Set Max delay if allies join late (see ETA & Delay Logic).

If no allies join before arrival, the attack resolves as a normal solo attack — FCS grouping only affects combat when at least one ally participates.

Defender notification

The target is notified when the leader launches, using the leader’s original ETA. Ally fleets joining later do not send additional incoming-attack notifications.

Alliance members receive a rally notification when a coordinated attack is created.

Joining a Rally (Participation)

Alliance members (and, if enabled, members of an allied alliance) can join an open rally from the fleet list (FCS filter) while the lead fleet is still traveling.

Requirements to participate

Requirement	Details
FCS enabled	Feature must be active for the joining player
Alliance access	Active membership in the leader’s alliance, or an allied alliance when the leader enabled inter-alliance participation
Same realm	Same realm level as the attack leader
Attack still open	Lead fleet must be traveling, mission type attack, participation not locked
Not the leader	You cannot join your own rally
One fleet per player	Only one fleet per player per rally
Rally not full	Default max: 2 allies (server-configurable). Pirate boss rallies use higher caps — see Pirate Bosses
Boss tonnage (boss targets only)	Lead and joiners must meet the realm minimum fleet tonnage (see below)
ETA rules	Your fleet must be able to join without breaking the leader’s max-delay setting

Pirate boss minimum tonnage

Against a boss-tier pirate stronghold, every fleet in the rally (leader and joiners) must meet a minimum total ship tonnage for that realm:

Realm	Minimum tonnage
1	100,000
2	1,000,000
3	10,000,000
4	1,000,000,000

Bosses primarily appear in Realms 3–4. This uses tonnage (not attack power) so defensive fleets still qualify if they commit enough mass. Details: Pirate Bosses.

What happens when you join

Your fleet attaches to the initiator’s attack.
Alliance members are notified that someone joined.

Locking & Unlocking Participation

Only the attack leader can lock or unlock the rally while the lead fleet is still traveling.

Lock — no new allies can join. Existing participants are unaffected. Does not change group ETA or start the battle early.
Unlock — reopen the rally to new joiners (while still traveling and not yet fought).

Use lock when you are happy with the current lineup and want to stop late joiners.

ETA & Delay Logic

FCS synchronizes every fleet in the group to a single group arrival time. All members share the same ETA shown on fleet cards.

Key concepts

Term	Meaning
Initial lead arrival	The leader’s original ETA at launch. Stored permanently and used as the delay baseline.
Current group arrival	The synchronized ETA for the whole group. Can move later, never earlier than the current group ETA when someone joins.
Natural travel time	How long each fleet would take to reach the target on its own, from departure. Stored per fleet.

When an ally joins

new group arrival = max(current group arrival, ally's natural arrival from now)

A faster ally does not make the group arrive sooner.
A slower ally pushes the group ETA later so everyone arrives together.

Max delay settings

Set by the leader at launch:

Setting	Behavior
0 min	No delay allowed. If an ally cannot arrive by the current group ETA, join is rejected.
15 / 30 / 45 min	Group arrival cannot be later than initial lead arrival + that many minutes.
Unlimited	No cap on how late the rally can be pushed by slow allies.

Examples

Example A — faster ally joins

Group ETA: 12:10
Ally would arrive at 12:05
Result: Group stays at 12:10

Example B — slower ally joins

Group ETA: 12:00
Ally would arrive at 12:10
Result: Group moves to 12:10

Example C — max delay exceeded

Initial lead arrival: 12:00
Max delay: 15 min (cap at 12:15)
Ally join would push group to 12:20
Result: Join rejected

When a participant recalls

If an ally recalls while traveling:

They are detached from the group.
Whether the group ETA is recalculated depends on what you are attacking (see below).

Against players and alliances the group ETA is sticky: it never moves earlier than the time already set, even if the slowest fleet leaves. This stops a rally from using a slow "bait" fleet to set a late ETA and then recalling it to strike sooner than the defender was told.

Against PvE targets the ETA stays dynamic and is recalculated from the remaining members' natural travel times — so it can move earlier when the slowest fleet leaves.

Target	ETA after a recall
Another player's colony	Sticky — never moves earlier
Alliance-held system center	Sticky — never moves earlier
Wakeheart (Riftwake Incursion)	Sticky — counts as AvA
Pirates and pirate bosses	Dynamic — can move earlier
Unclaimed system holders	Dynamic — can move earlier
Riftwake Siphon Spines	Dynamic — can move earlier

Joining always works the same way on both: a late joiner can only push the group ETA later, never earlier.

Battle start timing

The battle does not start when the first fleet arrives. It starts only when:

Every fleet in the group has reached its synchronized arrival time, and
All members are still in active coordination (traveling or arrived / waiting on mission).

Fleets that have arrived early wait until the full group is ready.

Recalling Fleets

Leader recalls

All participant fleets are automatically recalled (cascade recall).
The rally is cancelled.
Alliance is notified.

Participant recalls

Only that player’s fleet returns.
Group ETA is recalculated for remaining members.
The rally continues if the leader and other participants remain.

Return trip

Coordination only applies on the way out. Every fleet flies home on its own travel time — its own drive research, its own slowest ship — never the group ETA. A fast fleet that waited two hours for a slow rally still gets its own one-hour trip home.

When it leaves	Time home
After the battle	Its own full travel time
Recalled while travelling	Its own travel time × how far along the group schedule it got
Recalled from the rally (already arrived)	Its own full travel time
Sent home because the rally already resolved	Its own full travel time

Fuel refund

A recalled fleet gets back the share of its launch fuel it had not yet burned, measured by how far along the group schedule it was when recalled. The refund can never be more than the gas charged at launch: a fleet recalled at once gets it all back, one recalled at the target gets none. A fleet whose join was rejected after launch never flew, so it is refunded in full.

Combat Resolution

When the full group is ready, all attacker fleets are combined into one battle simulation.

Combined attack

Each participant’s ships fight together as separate attacker entries in the same battle.
Defender ships, stationed fleets, colony defenses, and hangar protection apply as in a normal attack.
Support Vessels repair across the group: 80% of each participant's vessels repair their own losses first, 20% repair other participants' losses first, and idle vessels help the other group.
War fatigue on loot is calculated from the lead attacker’s protection status against the defender.
If any participant cannot legally attack the target (e.g. protection rules), all fleets in the group are recalled and no battle is fought.

Attack protection & war fatigue

Loot reduction from war fatigue uses the leader’s fatigue multiplier.
If the defender suffers significant losses (5%+ ships/defenses or any loot taken), each participant may have the attack recorded against them for war-fatigue purposes individually.

Loot Distribution

On victory, total loot is calculated from the defender’s colony (subject to war fatigue and available resources), then split among participants.

Contribution score

Each fleet earns a contribution weight:

contribution = (fleet power sent + damage done + cargo capacity) × class loot multiplier

Where:

Factor	How it’s calculated
Fleet power sent	Sum of `(attack + defense) × ship count` for each ship type in that fleet
Damage done	Share of total attacker damage, proportional to that fleet’s fleet power
Cargo capacity	That player’s fleet cargo capacity (ships + bonuses)
Class loot multiplier	Personal class bonus on the contribution weight (see below)

Class loot multipliers

Class	Multiplier
Warlord	×1.2
Guardian	×1.1
Explorer	×1.1
Industrialist	×1.0

Mixed-class synergy

If the rally includes 2 or more distinct player classes, the group loot pool gains a bonus:

+2.5% per distinct class in the group
Capped at +10% total

Example: three different classes → +7.5% group loot access before the share split.

Share formula

your loot share % = your contribution / sum of all contributions

Each resource type is allocated with floor() (rounded down). Small remainders may be left unassigned due to rounding.

Practical implications

Bigger, stronger fleets earn more loot.
Fleets that deal more damage earn more loot.
Fleets with more cargo capacity earn a larger share (even before cargo limits are applied on return).
Class choice and mixed-class composition both matter.
On defeat, participants keep their original cargo (no loot gained).
If a fleet is destroyed in combat, its loot share is lost with the fleet.

Ship Loss Distribution

Attacker ship losses from the combined battle are split back to each fleet by ship type, proportional to how many of that ship type each fleet sent.

your losses of ship X = round(total losses of X × your count of X / total count of X)

Losses are capped so a fleet cannot lose more ships than it sent.

Each participant receives:

Their own battle report
Their own return fleet with remaining ships and their loot share
A push notification for victory or defeat

The defender sees one combined battle report with all attacker fleets merged.

Debris & Moons

Debris is generated from the combined battle as a single field (attributed to the lead fleet for harvest purposes).
Moon creation checks run on the defender’s planet as in a normal attack.

Limitations Summary

Topic	Limit
Mission types	Attack only
Who can start	Alliance officer, deputy, or leader
Allies per rally	Default 2 (server-configurable; higher for pirate bosses)
Fleets per player per rally	1
Who can join	Same alliance (always); allied alliance if leader opts in; same realm; not the leader
Join window	While lead is traveling and participation is not locked
Max delay presets	0 / 15 / 30 / 45 min / Unlimited
ETA	Synchronized across group; joining can delay, never hasten
Solo open rally	If nobody joins, behaves like a normal solo attack
Notifications	Defender notified once (on leader launch)
Pirate targets	Supported; boss rallies also enforce min tonnage — see Pirate Bosses

Quick Reference: Player Actions

Action	Who	When
Open rally	Officer / deputy / leader	At attack launch
Allow inter-alliance	Leader	At launch or while traveling (settings)
Set max delay	Leader	At attack launch
Join rally	Ally (or allied alliance if allowed)	While traveling & unlocked
Lock / unlock rally	Leader	While traveling
Recall (cascade)	Leader	Recalls everyone
Recall (solo)	Participant	Leaves rally, others continue

Glossary

Term	Definition
Lead fleet	The initiator’s attack fleet with alliance join enabled
Participant fleet	An ally fleet attached to the lead fleet
Group arrival time	Shared ETA for the entire coordinated attack
Rally	A coordinated attack with the alliance join option enabled
Lock rally	Leader closes the rally to new participants
Inter-alliance participation	Optional lead setting that lets members of an allied alliance join

References

Pirate Bosses — boss rallies, participant caps, min tonnage
Player Classes — class loot multipliers on FCS
Fleet Combat — attack rules, war fatigue, hangar protection
Fleet Stun — hangar and recovery after combat
Alliances — roles, diplomacy, allied alliances