Re: Mines as missiles or one-shot beams.
Correct, a "mine" in SE IV would have to be something like that to have any hope of damaging even something as "big" as a multi-megaton vessel. Now consider the distance over which the "mine" would have to act:
Assume a solar system with diameter 39 HAU (HAU is a "Hunpecked Astronomical Unit" equal to 100 million miles); this is about the orbit of Uranus in the Sol system. SE IV displays a star system on a 13x13 grid, so each side of each square is 3 HAU.
Assuming movement is limited to a distance 1.5 HAU "above" and "below" the mean plane of the planetary orbits, a ship/fleet would traverse a series of "space cubes" 3 HAU thick by 3 HAU long and 3 HAU wide. Now divide each cube into 100 columns (10x10) with a square cross-section (mines are limited to 100 per cube, so each column must have a mine to guarantee one "hit" on a ship passing down the column). A column is 0.3 HAU on a side, with a center-to-edge distance of 0.15 HAU or 15 million miles; this is the mine's minimum radius of action. Actually, the columns should be circular in cross-section, which means a mine's target radius would have to increase to overlap its neighbor's.
Of course in SE IV a fleet always hits a minefield, no matter how sparse, and it hits every mine until either the ships or the mines are gone. This means a mine's radius of action is at least half a cube side, or 150 million miles (in this example, anyway).
However, this doesn't translate to the battle map, where a mine would immediately "hit" an enemy ship (with better-than-Talisman accuracy) when dropped. Thus SE IV contradicts itself, which isn't surprising when one tries to make the terrestrial "mine" concept work in space (which is REALLY REALLY big).
In reality, the space analogue of a terrestrial mine is a ship.
