Build:Unused Structure Units
3.3 Unused Structure Units
Once you finish building a starship, you may find that you have Structure Units (SU) “left over”. In other words, you haven’t used up every possible SU for a vessel of that Size. However, this isn’t a problem. It simply means one of two things.
First, it may mean that you don’t need as many SUs as you could possibly have. That’s fine. Instead of deciding that your Size 6 ship has a full 2,500 SUs, you simply note that it has 1,683. Not every ship has to have the full SUs for its Size category—in fact; few do. Don’t feel the need to cram the hull full.
Second, you can decide that the unused SUs represent room for expansion. As the series progresses, you can gradually upgrade old systems or add new ones to occupy some of that space. For example, during the Dominion War many ships were rushed into production without their normal full complement of equipment, so that they could fight. After the war ended, Star Fleet—slowly but surely—got around to filling all of those half-empty hulls.
In either case, the unused SUs have no effect on combat. When all of a ship’s used SUs are removed by damage, it’s been destroyed, regardless of whether it had any unused SUs available.