Fleets are groups of ships. They move at the speed of the slowest ship in the fleet. (Unit speeds are listed in the unit tables.) Fleets are able to move between planets and stop moving when they arrive at the destination planet. Fleets cannot be ordered to stop in open space. If a fleet includes transports, the transports can carry resources or ground units.
Transit time between planets is calculated from the second that the movement order is issued. Moving fleets that are not orbiting a planet cannot be attacked by other fleets. They can still be attacked by jumpmissiles. Players can issue new destination orders to moving fleets at any time.
Fleets appear to be treated as being “in transit” and stop being able to use their weapons at the instant that a movement order is issued. However, they appear to remain in orbit of a planet and can be fired at by other units until the end of the current watch plus the time that their speed would take them >1 LY away from the planet. For jumpships this window of vulnerability is no longer than 1.2 seconds.Starfrigates and starcruisers take up to 5 watches to leave orbit. The same is true for fleets arriving at a planet; a fleet cannot use its weapons until its “in transit” status clears, but can be attacked the instant that it is within 1LY of the destination planet.
No type of ship cannot enter a rift zone, but ramjet and jumpship fleets are often able pass through the gaps between rift zone areas.
Starships cannot enter nebulas. They only move through open space.
Ramjets cannot leave nebulas. They cannot pass between different nebula types (this is a bug). As of Era 3 they are rarely able to move at all (this is a bug).
Jumpship fleets (containing 100% jumpships) can only move to planets within 250 LY of a jump beacon. Areas in your empire with an active jump beacon can be seen by selecting a jumpfleet. Jump beacons only exist on jumpship yards and on the imperial and sector capitals under the Fire & Movement doctrine. The jump beacon is a property of these designations' primary structures (the fleet HQ and jumpship yards structures) and can only be removed by redesignating the planet.
If a jumpship fleet ends up outside beacon range (e.g, if a nearby beacon is captured,) it can still jump back into the range of any owned beacon. Jumpfleets can cross space outside of beacon coverage as long as their destination is inside a beacon's range. Pure jumpfleets are unable to travel to destinations outside of beacon coverage, but jumpships can be moved outside of beacon coverage by transferring or deploying them into a “mixed fleet” that contains starships or ramjets.
If you put jumpships in a fleet with starships or ramjets (producing a “mixed fleet”), the fleet will move at the speed of the slowest ship in the fleet and does not require a beacon. If a mixed fleet containing both jumpships and other ships turns into a jumpfleet while moving (e.g., if it gets hit by jumpmissiles and all the slow ships are destroyed), it will stop moving and you must issue it a new movement order. This is the only way that a fleet can stop moving in open space.
Fleets will not always use the best route to get to a destination if there are obstacles (e.g. nebulas or rift zones) in the way. You may need to manually order fleets to travel a planet that is on the way to the destination, then give them a new movement order once they arrive. Fleets often have trouble finding paths through rift zone gaps.
Fleets can move outside the boundaries of the map. Nebulas that extend to the edge of the map are not absolute impediments to starship movement if the starships are able to go around them. Some nebulas extend beyond the boundaries of the map but fleets can still pathfind around the invisible parts of the nebulas.