Provisionally, until I get more feedback on the subject, due to the outstanding question:
How fast should a projectile weapon be able to fire a slug?
I am implementing a hard-limit on how fast handheld or shoulder-mounted weapons can fire a projectile to 8,000 m/s (roughly Mach 23). This is a hard-limit for railguns and coilguns that use other means than those of conventional firearms (gunpowder or other explosives) which can be carried in the hand, shoulder-mounted, or otherwise used and carried by a single person. It was suggested by a player to have a railgun that can propel a round at just over 1% of the speed of light, which is clearly absurd. Since the escape velocity of Earth is a little over 11.1 km/s, I figure that if one fires their weapon and misses at STP (standard temperature and pressure), their bullet should not escape the confines of Earth’s gravity and go into orbit, or one should not be able to strike a vessel in orbit from the ground with a railgun one can carry.
Allowances are made for ship-mounted or ground facility weaponry that can have a higher power source, far more bulk, and potentially can propel a round faster.
Conventional Firearms
Conventional firearms of any design are limited by what is on hand, they are limited by a leeway of 25% increase from modern firearms for alternative explosive fuel sources and materials. Conventional firearms is defined here as being any firearm which propels a hunk of material using some force of explosive pressure or high pressure release. It is the opinion of the server admin that the human race has had a long time to perfect the production of handheld instruments of death using explosive charges to propel rounds, certain ballistic limitations of STP also exist that limit things.
At any rate, any conventional weapon is hard-limited to no faster than a 25% increase over the conventional weapon’s real-life firing speed. Such an increase also will have to be explained by some variation of describing why the fuel is different or shape of the round.
Round-Design
Rounds that approach the hard-limit will require explanation, what are they made of that they can withstand the force of air resistance at the velocity and should also have some note about their size and shape. One cannot just fire a blunt slug at those speeds, as it would become aerodynamically unstable very quickly, the round would also be subject to severe deformation due to heat from air resistance. Rounds traveling at speeds in excess of Mach 4.5 will also need to be aerodynamically designed in order to maintain flight stability. In terms of in-game explanations, it is not expected for players to have specific design specifications, but it is expected that a round is shaped with a small pointed nose and tapered back-end to allow for aerodynamic stability. Anything else would be aerodynamically unstable.
Grandfather Clause
While normally I extend a grandfather clause to new guidelines and rules, that is not the case here, and weapons currently in game which violate this rule will require special approval to keep.
Final Note
This is not a combat oriented game and it should be noted that the weapons used are used to further story – allow characters to have the opportunity for sufficiently “bad assed” moments but also sufficient risk during combat or other encounters. As such players should realize that while it is certainly canonical within a science fiction setting to have weapons that do massive amounts of damage, that actually makes play harder – the goal of play is to enjoy a situation which your character must fight to survive or overcome an obstacle, not insta-kill an enemy and celebrate a job well done.
This is the reason in canon Star Trek, during the Dominion War, they did not use the phasers to their full potential. Even though canon directly says that a single man with a hand phaser in the 23rd century (TOS) can annihilate thousands of infantry who are unprotected and during the course of TNG it is seen that phasers on a wide-beam setting can effectively incapacitate large numbers of people, it was because it worked well within the confines of those stories. The stories of the Dominion War would have lacked a level of personal risk among the characters to have things be that easy, rather than use that they told a different and far more relatable story of phasers used in the same line as conventional weapons with line-of sight restrictions. This was done to great emotional and dramatic impact, seeing the “horrors of war”, even though it is technically incorrect.
We strive to have challenges for characters to overcome that require effort and thought, situations that (without being horribly convoluted) force the characters to take risks, risks that make the end result more impactful to the players and audience of the gaming sessions.