The following is a list of the three main factions and their main infantry weapons for a tabletop science fantasy RPG. I'm looking to expand this list with weapons that fit the aesthetic of each faction. (I have already considered coilguns, they just aren't listed.)
HCSA: The Human Central Space Authority is technically only the military of the Human Cosmic Republic. (Don't let the name fool you, it's actually an oppressive plutocracy with a strong fundamentalist religious bent.) Most people still refer to it as the HCSA, because the only time the government actually has more control over a territory than any single corporation is when it declares martial law, so in most people's minds the military IS the government. It's a serious problem. The actual government of the HCR is often called the "Holy Cee", which started as a derogatory nickname observing that the only part of it you ever see in action is the propaganda arm whose sole job is to deliver speeches and proselytise. It also works given that the military has a religious test for entry. The result is a state where a supposedly representative democracy is largely left under the control of corporate entities, and when the government does step in it's actually controlled by the theocratic military rather than the elected government, and the elected government is a bunch of seemingly useless blowhards who give a good speech and never do anything. It's not a great place to be, and of course it sees a lot of rebellions on the frontier and terrorist activity in the core worlds.
Firearms: Firearms are good, solid weapons. Cheap, easily produced, easy to use, reliable and the fastest firing ranged weapons in existence by any metric that actually matters. Firearms don't deal a lot of damage, and their effectiveness against armour compared to other weapons depends largely on the load and the armour, but they're solid pieces nonetheless and have served the HCSA (and its many, MANY rebel factions) well for centuries.
The standard-issue assault rifle loads a 5x40mm cartridge with a 30-round capacity, and fires 900 rounds per minute to deal 1d6 puncture damage with a 19-20 x3 critical threat on semi-automatic. You can also fire on full auto either in bursts (as default), a longer spray, or emptying your magazine, all for a random number of hits and a fixed 3 damage each, it becomes treated as a scattershot attack. It has very low recoil and a slight delay before the recoil is felt, meaning that its automatic fire modes hit more of the rounds fired than other automatics. A burst hits 1d2+1 (expends 3 rounds), sprays hit 3d3 (expends 9 rounds) and emptying the magazine hits 3d12-6 (clearly 30 rounds), all hard limited to the number of remaining rounds in the magazine of course. Regardless, it has a penetration of 6, meaning it ignores 12 DR and deals an additional 6 damage to armour hit points. Its range increments are 40m, 200m and 1000m, losing accuracy as it goes.
Spikers: Specialized slugthrowers designed to counter the hallowed's personal energy shields. They're made in an intentionally ludicrous calibre and designed to only fire armour piercing, fin-stabilized discarding sabot munitions with 1/2 the diameter, while it rarely penetrates a shield, to usually drain all of the shield's energy and leave the target vulnerable. Spikers are known for their brutal recoil, slow rates of fire (as only a lunatic would make them fully automatic) and short range, but being able to one-shot even very strong personal shields and having better armour penetration means they tend to outperform conventional firearms against the Hallowed despite these drawbacks. It also inspired a dance move called the "spiker jerk", where a dancer pantomimes the body movement of firing a high-recoil firearm (like a spiker) at least twice, though generally with their fingers outstretched to disguise it being a reference to a weapon (and thus a veiled threat).
A standard-issue spike rifle loads a 20mm cartridge to fire a 10mm spike, it has a 10-round capacity and deals 1d10 puncture damage with a 19-20 x3 critical threat and a penetration of 15. Its mass gives it a bonus to break energy shields, making a check with 1d20+10+Dex against 10 plus the shield's remaining energy (after the damage is dealt). If this succeeds, the energy shield is completely expended and the target is vulnerable to further attack. It has no full-auto fire mode, because it already kicks like a shotgun and that'd be really stupid. Its range increments are 40m, 120m and 200m, also losing accuracy as it goes.
Lasers: Lasers were humanity's first energy weapons, and today are still its most used. Lasers are blocky and not very ergonomic, there's a slightly longer delay between pulling the trigger and it actually firing than there is in a firearm, and it while its pulse is almost imperceptibly brief it's still long enough to require the target be tracked a bit when firing or the energy gets spread out. Reloading it is also difficult and time-consuming as replacing its five-charge power supply isn't intuitive at all, so people need to be trained in how to manage every aspect of the weapon. Once they do, it fires extremely slowly, taking several seconds to recycle (and thus being hard limited to one shot per round, regardless of how many actions you get), and it loses damage over distance fairly quickly. However, it's perfectly accurate at all ranges and, at least close up, deals a tremendous amount of damage. The shot from the laser is sufficiently powerful to generate a damaging explosion, and that presents additional applications such as shooting the ground to hit enemies around cover.
A standard-issue laser rifle fires a 500MW infrared laser beam with a 1cm diameter for 1ms. It deals a ranged touch attack with 5d6 energy damage to the target with a critical of 19-20 x2, and generates a blast that deals 5 energy damage (no crit) within 2m and 1 damage out to 4m, dropping almost any soft target in a single shot. The impressive damage of the laser also allows it to perform well against most forms of armour, and it's considered a touch attack so AC doesn't work on it either. Its range increments are 250m, 500m and 1000m, and it loses damage as it goes.
Pulse Projector: Only kindof a directed energy weapon, pulse projectors generate an electromagnetic pulse that destroys unhardened electronics. Hardened electronics survive the attack, but some systems need to be shut down temporarily (such as sensor systems) and restarted. This allows a pulse projector to do some potentially devastating things, like disable an airplane's sensors from the ground to prevent it from firing guided missiles, or intercepting incoming missiles. Most vulnerable to pulse projectors are robots, and drones in particular, which are completely shut down and will take several minutes to restart. If they happen to be flying at the time, this is often as good as shooting them down. Droids, and specialised direct-control drones, will only take about one minute and have a better chance of survival, but still not a great one.
The standard-issue pulse projector is a line attack that stops when hitting an object larger than 2mx2m. All unhardened electronics (cell phones, tablets, laptops, cameras) take 1d6 electric damage and are usually destroyed. Robots make a fortitude save with a DC of 20, 10 or 5 to avoid being completely shut down and taking 1d6 electric damage. The short range is up to 2.5km, medium range is up to 5km and long range is up to 10km. Hardened systems with exposed components save instead with an unmodified D20 roll, and if they fail they have their exposed components (sensors and communications, heads up displays, energy weapons) shut down and take 1d6 electric damage. It can fire once before it needs to be recharged, and takes a round to charge before it can be fired.
Electro-lasers: Electro-lasers are modified lasers built to destroy electronics, and in particular robots. Since it doesn't take nearly as good of tech to make battlefield robots as any of the main factions have, and the droid lords operate entirely using robots, it's good to have a weapon that can destroy them easily. Electro-lasers, unlike their EMP-based counterparts, often completely destroy a robot's circuitry instead of just triggering a failsafe and causing them to restart. Unfortunately, their range is also terrible. That's okay, they aren't meant to have a lot of range. They're meant to be a one shot, one kill weapon for dealing with ground-based droids and their short range is acceptable for that purpose.
The standard-issue electrolaser functions like an ordinary laser in most ways, except the beam is 50MW for 10 milliseconds and generates a substantial plasma channel, into which electrodes release a single-phase AC current for 10 milliseconds with a power of 50MW and a voltage of 500,000 volts, and it's able to hold 5 rounds. This shot deals a ranged touch attack for 5d6 energy damage with a 19-20 x2 critical and a 5 damage blast (no crit), but it also deals 5d6 electrical damage (no crit) and delivers the same effect as a pulse projector with a save DC of 10 plus the damage dealt (after mitigation). It also affects hardened systems with exposed components to same way a pulse projector does. Not only do these weapons generally destroy drones and droids, they very easily kill soft living targets. Unfortunately, their range increments are 50m, 100m and 200m, and they lose damage with range. As an electrolaser will average 40 damage when unmitigated, it is an exceptionally deadly energy weapon.
Particle Projectors: Also known as a particle "sprayer" in atmospheric contexts, a particle projector fires a series very dense, high-energy beams of neutral particles in pulses every 10ms for a full second. It also doesn't really work as originally intended when used by infantry in atmosphere and the project was initially going to be scrapped, but the chaotic results of attempting to use it in atmosphere still allow it to be an effective weapon and the soldiers who tested it demanded it be brought to production as a CQC weapon. And so, it was. The main problem with the particle projector in atmosphere are, well, the atmosphere. It causes the beam that should otherwise be coherent to scatter and refract a lot more than it should. This creates a visible spread to it, and also causes it to dissipate fairly quickly. The result is a shotgun-like energy weapon that has short range but deals a tremendous (if pretty random) amount of damage.
The standard issue particle projector gun takes a round to charge and a single action to fire, and is treated as a ranged touch attack hitting 1d10 times for 2d10 energy damage with 10 penetration and a 5 round capacity. It can also be raked across an area, becoming a fan attack that hits for 2d10 (with 10 penetration) up to 10 meters away, and beyond that 2 damage (with 1 penetration) up to 20 meters away. As the only energy weapon that has penetration, this gives it a unique advantage against armour and makes up for its low damage per application. However, it loses damage extremely rapidly over distance and its ranges are only 10, 20 and 40 meters. As it averages 60.5 damage up to 10 meters, but drops harshly down to only 11 beyond 10m and to a measely 2 beyond 20 meters, and it takes a bit to charge, it's a challenging but extremely lethal weapon.
Hallowed: The Hallowed Union. The Hallowed Union is a theocratic union of individual "sovereign nations" that are not actually sovereign nations because they're not independent and can't leave. They do have some autonomy to govern themselves, but the Union has its own government that oversees them and overrides the law of individual nations beneath it. At the head of this is a single race of nobility that runs their religion and the religious branches of the government. Which, to be clear, are both the judicial and executive branches. The former because their laws have a religious basis and serve religious goals, and the latter because their executive branch is monarchal, and it derives authority from divine birthright. They supposedly balance this by not taking part in the legislative branch, and it's true and it does mean the other races have a lot of power within the Union, but theirs still has more than any other and it's justified entirely through religious means. The Hallowed are presently at war with the HCSA, having offered humanity the chance to join their union and been refused, primarily because of those in power would like to keep it and justified because converting religion would be so like, totes lame. Somebody started shooting during the negotiations, it's hard to say who, and now they're determined to make the HCSA join by force. Though honestly, it's hard to say normal people would be much worse off as part of the Hallowed Union.
Blasters: Blasters are highly focused directed energy weapons with a fast refire rate, designed to function more like the conventional firearms that, for the Hallowed, they ended up replacing. Blasters still have slower fire rates than most firearms, but doing far more damage per shot than firearms do. Blasters fire a very small, coherent bolt of extremely high temperature positively charged plasma that, like a laser, produces an explosion when it hits. It produces an explosion as well, but it still produces one and it's a much faster firing weapon. This makes it highly impractical in CQC, but its lethality keeps enemies distant. The magnetic containment system of the laser also gives it an advantage when fired at moving targets, counter-intuitively given its slower velocity: The bolt will follow the aim of the weapon when it is moved, allowing a shooter to aim directly at a target and fire, and even correct their aim if it was initially off. This is assisted by having the weapons come standard with magnified holographic displays and laser sights, allowing the shooter to fire and simply keep the dot on the target for the fraction of a second it takes to hit.
The standard blaster rifle fires 6MG of hydrogen plasma at nearly twelve million Kelvin, delivering a total energy of over one megajoule, holding enough energy and gas for ten shots. Plasma is not very efficient and more of the damage is thermal, so it isn't as powerful as it sounds, but it still deals a ranged touch attack 2d6 energy damage with a 1d6 fire damage (no crit) explosion within 2m, 1 damage out to 4m. It has advantage to attack rolls whenever it's firing a single shot per attack action, and while it gives that up to fire faster it suffers no other penalties. The standard rifle can be charged for more damage, heating more gas to the same temperature and consuming five times as much gas and energy to deliver 5d6 energy damage with a 5d6 fire damage (no crit) explosion within 2m, 5 out to 4m. Its range increments are 30m, 60m and 120m, and it loses damage with range.
Ion blasters: Ion blasters are blasters designed to deliver a very strongly negatively ionized plasma instead of the standard somewhat positively charged plasma. These weapons are designed specifically to counter the Droid Lords, and perform much like standard blasters except they deal electric damage as well as energy damage, travels much faster, has better range and performs even worse against armour.
The standard ion rifle is much like a standard blaster rifle, except it fires only 4MG of extremely negatively charged deuterium plasma, which is more or less just a lot of electrons and neutrons, at over fifteen million Kelvin. It deals a ranged touch attack for 1d6 energy and 1d6 electric damage (no crit) with a 1d6 fire damage (no crit) explosion within 2m, 1 damage out to 4m. Charged, the blaster deals 3d6 energy and 3d6 electric (no crit), with a 4d6 fire damage (no crit) explosion within 2m, 4 out to 4m. The bolt travels nearly twice as fast due to its stronger charge, and has range increments of 40m, 80m and 160m, losing damage with range. As it deals electric damage, it has the same effect as a pulse projector or electrolaser in that it forces robotic opponents to make a fortitude save with a DC of 10 + Damage or be rebooted.
Stun blaster: Not a true blaster, stun blasters emit a focused, powerful series of concussive shockwaves, firing four times in just over a fifth of a second. This simulates a very powerful 19 hertz sound wave, allowing the blaster to not only deal damage through the forces involved, but to blind and deafen the target. This weapon is intended as a less-lethal weapon and is standard issue for law enforcement, military police, prison guards and body guards, where killing is frowned upon. It doesn't always work, though. No less-lethal weapon is truly reliable, but stun blasters are notoriously bad because not only does it sometimes fail, being blind, deaf and disoriented does not guarantee a target is no longer a threat. Especially if they have a weapon they can continue to fire or swing. That said, a quick firing stun weapon that can hit multiple assailants and holds plenty of shots is good enough to be worth it, even with its shortcomings, and it's generally agreed to be better than an electroshock weapon.
The standard stun pistol (keep in mind this is being compared to rifles here, but it is overwhelmingly more common than stun rifles are) delivers a sonic line attack, dealing 1d4 sonic damage, and is able to fire ten shots before reloading. The target must succeed a fortitude save, DC 10 + Damage to resist being blinded for one round, deafened and disoriented (treating them as flat-footed) for one minute. This effect strikes all targets within 10m in a line for full effect, and up to 20m for 1 damage, no risk of blindness and only one round of deafness and disorientation.
The Droid Lords: The Droid Lords are a collection of robot factions. All of them have their own plans and agendas, and while most of these seem purely related to wealth and resources, a few of them take moral stances and even do things for fun. Which, of course, has lead some to question if they're actually all machines. Examination of destroyed robots has shown some degree some degree of psionic infusion and some organic components in the autonomous droids, but they're still mechanical and shouldn't be capable of higher reasoning or complex emotions. Examination of drones operated by local command nets has shown even less complexity, they just follow orders. Examination of the command nets has also shown that they're taking orders remotely. Further examination has revealed that the ones robots that seem the most... Alive, the ones that do things for fun, take moral stances and that easily pass turing tests, they're also drones, being operated remotely. Further digging has revealed that either higher AI or organics hidden somewhere in their controlled territories are the source of this, and further investigation suggests the latter. Somewhere, deep inside the Droid Lord territories, are living beings that manage the higher functions, set priorities and conditions, negotiate with the other factions, choose wars and yes, remotely operate individual drones sometimes. (Which seems a waste of superluminal communication, but whatever.)
Gyrojet gun: The droid lords like old, discarded technology in a way few others do. If something didn't work, they tend to pick it up and try to find a way to MAKE it work. This is just such a weapon, firing miniature kinetic rockets from a gun barrel. Gyrojets are not very accurate, but they are both recoilless and very powerful. Having better penetration, performing better outside of atmosphere and having an electric firing mechanism for a higher rate of fire allows gyrojets to be highly lethal against armoured personnel. The problem is, as its original detractors pointed out, if something's close enough to hit you can't kill it, and if it's far enough to kill you can't hit it. But still, in a weapons system that fires as fast as theirs does, that might not matter too much.
A standard gyrojet light anti-personnel weapon fires 14mm gyrojets and feeds from a belt at 1800 rounds per minute, hitting with a scattershot attack 1d10 times or 6d6-6 times for 8 puncture damage (4 at short and long range) with 20 penetration, depending on whether you use the standard attack burst or the single action spray, the former consuming 10 shots and the latter 30. It has a short range of 30m, a medium range of 300m and a long range of 3km, gaining damage but losing accuracy at medium range and then losing more accuracy and damage at long range.
Micromissile launcher: Micromissiles are missiles fired from a reloading launcher. Droid Lord micromissile launchers are belt-fed, allowing them to fire 20 rounds per minute with each launcher and generally having at least 2 on a unit. Unfortunately, the missiles (as the name suggests), have to be fairly small. Micromissiles are laser-guided precision missiles, delivering a variety of warheads but the most common being high explosive anti-tank. Despite the name, tanks can outright ignore any number of these missiles and the primary purpose is to defeat lighter vehicles, power armour and other things that are generally too tough for gyrojets but not nearly tough enough to require anything heavier, and to do so at long range.
The standard micromissile for a man-sized combat droid is a 25mm laser-guided missile with a shaped charge warhead, hitting for a direct 5d6 energy damage ranged touch attack with 30 penetration, and scattering shrapnel for 1d6 pierce damage within 5ft, 1 within 10ft. The missile's precision guidance gives it advantage to hit, it has a minimum range of 30m and a maximum range of 3km, otherwise it's equally effective at all ranges as missile weapons tend to be.
Jet Cannon: This frankly insane disposable weapon detonates shaped charges to launch explosively formed penetrators at the target. That is to say, they detonate bombs attached to their chassis to launch hypersonic molten copper at enemies, and then it detaches the containment unit. The system is designed to focus the blast away from them and make sure the copper flies where they aim it, but it's also not a very accurate weapon and it does have risk associated with it if the system designed to protect the chassis fails. This ultimately doesn't matter, they're just robots, and the droid lords can fix them if they break or have more made if they're destroyed.
A standard Jet Cannon for a man-sized combat droid, generally only carrying two when they're present, deals a 10d6 energy damage ranged touch attack to the target, 19-20 x2 critical, and has 60 penetration, delivering a 2d6 bludgeon damage blast to all within 10ft and 2 damage within 20ft in a cone in front of the blast, allowing it to kill mechsuit personnel in a single shot. The shot of a Jet Cannon is a game ender if it hits. It has range increments of 20m, 100m and 500n, losing both damage and accuracy. These weapons are the reason why the primary tactic for destroying combat droids is sneak attacks with electrolasers, rather than shock troops with power armour or mechsuits.
Everything other people have: The droid lords trade and salvage enough that they have a healthy access to HCSA weapons and limited access to Hallowed weapons.
