Official rule text
16.4 Fighters and ground forces are not assigned to specific ships, bombardment roll. A hit is produced for each die roll that is except while they are being transported. equal to or greater than the unit’s “Bombardment” value. RELATED TOPICS: Movement, Capacity, Transport
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Source: Twilight Imperium: Fourth Edition - Living Rules Reference: Prophecy of Kings
Expansion: Prophecy of Kings
Version: 2.0
Reference: Rule 16.4