ACS lets several fleets coordinate one attack or support the defense of a target. In Inter-War an ACS group has a fixed type and coordinates, a limited number of mission slots and validation rules that keep joining fleets consistent with the leader’s plan.
How do you create a joint attack?
The leader sends an ACS attack to chosen coordinates and creates a group. The default group limit is 4 mission slots. Additional fleets may join while a slot remains free. The group is tied to one galaxy, system and position.
Who may join?
The leader or another player from the leader’s alliance may join an ACS attack. Defensive support is broader: you may support yourself, a member of the same alliance or an accepted buddy.
A joining ACS fleet must match the group type and coordinates. The game also checks whether the leader targets a planet or a moon; the joining fleet cannot change that target type.
How is timing synchronized?
When joining an existing ACS attack, the planned arrival must match the battle time of the group. Correctly joined fleets are then settled as one battle context instead of separate independent attacks.
How does joint defense work?
HOLD and ACS Defend missions can cover a target when they arrive no later than the battle and are still present when combat starts. A fleet already returning does not participate. Planet and moon targets are treated separately, so support must cover the same target type.
Important rules
- default group capacity: 4 mission slots,
- group coordinates are fixed,
- planet/moon target type must match,
- ACS Attack uses the normal player-protection and attack-limit rules,
- defensive support requires self, alliance membership or accepted buddy status.
Additional ACS restrictions
An attack group has at most 4 mission slots and keeps one fixed target and target type. An ACS Attack may be joined by the leader or a member of the leader’s alliance. Defensive support can protect your own target, an alliance member or an accepted buddy. Joining ACS does not bypass normal PvP protection, attack restrictions or the player’s fleet-slot limit.
Timing matters on defense: the supporting fleet must already be present at the target when the battle is resolved and it must not be returning. A HOLD/defense mission may arrive earlier, but its stay must cover the battle timestamp. These checks prevent a fleet from being counted merely because its route crossed the target at a similar time.
FAQ — ACS
Can someone outside my alliance join my ACS attack?
Not under the current ACS Attack rule. Joining is allowed to the leader or another member of the leader’s alliance.
Must a defending fleet arrive in the exact battle second?
No. It may arrive earlier, but it must still be at the target and not returning when the battle occurs.
Related FAQ: How do alliances work? · How do fleet and expedition slots work?