Damian Walker

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Starship Travel

Monday, 27th November 2017

Yesterday I wrote about how ships will be designed in Star Governor. Today's post is more about how they'll work. At the time of writing, I haven't decided which will be implemented of the two systems I described yesterday, so some things are left deliberately vague.

Firstly, ships will exist only in two forms: as part of the orbital fleet around a planet, or as part of a character's fleet. Characters fleets may also be in orbit around the planet, but they may also occupy any point of a star system. They may also be in transit between two star systems.

No ship may therefore move from its place of manufacture without a character present. A star governor can with one shipyard build defence fleets for a number of planets; a ship is manufactured, joins the governor's fleet briefly to be shipped across the star system, and is then left in orbit around its destination.

As mentioned before, travel within a system will be, if not instantaneous, at least fast enough to be completed in the course of a turn. The details of how the ships move aren't imposed upon the player. Possible explanations are solar sails, long turns or a fleet of planetary tugs which aren't brought to the player's attention (much like the courier ships carrying orders and reports between the emperor and distant characters).

A fleet will travel between systems at the speed of its slowest ship. It makes sense, therefore, to have all ships in a fleet the same speed. Players might want to settle on a "standard" speed for their ships, with only dedicated scout fleets or colony fleets having faster or slower engines.

There'll be a theoretical maximum starship speed for an empire: let's say, for the sake of argument, seven map squares. A hypothetical ship with all of its space allocated to star drives, if we ignore the fact that it couldn't carry any fuel, would reach a star 7 squares distant in one turn. This speed is modified by an empire's technology rating for star drives, which would start between 0.5 and 1.5 before any research is done.

Of course, fuel is necessary, and so some space must be given over to it either as hold (in the simple system for ship design) or fuel tanks (in the advanced system). Again, a theoretical ship whose entire hull is filled with fuel would have a theoretical maximum distance it could travel. I'd like to make this at least twice the maximum speed so that a ship can make full use of its drive capability, there & back at maximum speed, without having to refuel at the destination. 21 or 27 squares would be good theoretical maximums. These would be modified by an empire's technological rating for fuel efficiency, which starts out between 0.5 and 1.5.

There would be three types of fuel usage. A fleet having stocked up with refined fuel, produced by refineries on planets, will travel at the full speed its technology allows. If low on fuel for a return journey, a fleet can pick up unrefined fuel at any gas planet, after which the whole fleet is considered to be running on unrefined fuel. The penalty for this inferior fuel is that the fleet runs at half speed. In the case where no gas planet is available, a fleet might have to run on empty, limping home at a tenth of its usual speed. This all guarantees that a novice or AI player doesn't leave fleets uselessly stranded around distant stars. Fleets are refuelled (having any unrefined fuel replaced with its refined equivalent) on arriving at an allied planet with the required facilities.

This description, lengthy as it is, leaves out the mechanics of transporting passengers and cargo. How many passengers are needed to start colonies? How many goods can be stored in the hold? And how would the AI know when such transportation is needed? These details will be addressed in a future blog post.