What does save as template do?

It Saves the Hull designs created without any components such as engines or weapons. So the actual 'creation features' are saved to be used at any time since it does not have anything in it. 

When you design a new ship, there's the "blank" template (the little cube) and the other pre-designed ships you can choose from (Defender, Cutter, Fury, etc.).  If you save as a template, that design will be added to the list of designs to choose from.  If I make a Small ship and call it "Best Ship Ever," I can then start a new game, research small hulls and choose to make a new ship based on "Best Ship Ever" - no other tech needed, it will appear right along side Fury and the other small ready-made ships.  However, save as template will not save the position of any equipment - shields, weapons, engines etc.  So I must place the parts on and save it again - with a different name, if I want - (but NOT as template this time) before I can tell my shipyards to build it.

Back in the GalCiv 2 original release, players would often design fancy ships, but then they would add advanced weapons to them. The fancy weapons added to the techs needed to unlock the ship in later games when they started over, so the cool ship designs would be unavailable until they researched the same techs needed to build the originals. To solve this problem, players started saving fancy ship designs without any components, so the only prerequisite would the be techs needed for the hull size.

In the first expansion, the devs took note of this and added the ability to save ship templates. Any newly designed ship could be saved as a template, so you would get a new ship to build, and a copy in another list that you could select without prerequisite techs (short of the hull size).

Edit: Basically, it is a tool for cool looking ships, not designing functional ships. Mind you, nothing in this game stops you from making a ship both functional and awesome looking.

Thanks all for the info. I have been avoiding actual ship design as they are not likely to be compatible from release to release.  I am just using  game ships and changing component and if i saved it with template checked i couldn't find it again.

Appreciate the explanations.

I disagree, I have a cargo hull loaded with sensors & life support, & engines as a template, you can use them to fill role gapsin the default ships too (a very useful feature)

While the above about using the template to create functional ship designs is true, there is another reason for template creation.

The real need for the templates is that (custom) ship classes use them to allow the auto ship designer to generate the various versions of that ship. So there is a Terran_Scout template (in "steamapps\common\Galactic Civilizations III\Designs") which in combination with the TerranScout class (as defined in ShipClassDefs.xml) and the ScoutBlueprint (as defined in ShipBlueprintDefs.xml) allow the auto ship designer to create the various incarnations of the Scout (Scout M1, Scout M2, Scout M3, etc....) depending on the techs you have researched during the game play.

Is this a modder only thing or will "save as template" update the *.xml's based on the assigned role?

Consider it a modder thing.

The "save as template" will not touch any .xml files. And in the current version you can no longer specify an assigned role. The game will assign the role depending on the actual active components on the ship.

So if you don't want to mod, you can still use the templates as described above (by Larsenex, Turkwise, and DivineWrath) as a tool for creating hulls.

Thesw  Man that was a quick response, thanks for the info.