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Tl;dr what are some sci-fi weapons and troops that you would say “counts as” in a game you were playing in?

This was inspired by this thread, specifically these two posts:

Sgt. Cortez wrote:

 Nevelon wrote:
Both Jedi and Space Marines are very dependent on plot armor. When The Force/Emperor is with you, you can stand against literally endless hordes and not falter. But when the plot shifts, and your time is up, you and all your friends go down like chumps to mooks.

Could the auto-senses in a marine helmet, or just their instincts and training spot a predator? Maybe. Would the plasma just burn through the ceremite breastplate? Also maybe. Depends who’s the protagonist and what the demands of the story are.

One of the issues debating fictional universes.

Is the pred shooting Tau pulse rifle plasma? Or the Good Stuff (tm) that one-shots marines?

Indeed. A friend of mine, who is a Marvelfan, keeps arguing that Wolverine would be able to kill hundreds of Marines while I'm like, no, Wolverine would just be a Space Wolve Pack leader with a pair of Lightning claws, feel no pain and It will not die, Marines are just that good. Iron Man is also just a more handy crisis suit.

Is Batman simply Konrad Curze? Probably not, he's just an imperial Guardsman with Konrad Curzes gear.

Same with the Predator. I'd say his plasmacaster is indeed a plasma gun and his wristblade is a lightning claw, so he lacks armour for sure, but he'd be a good match for a Space Marine.Though admittedly predators have been beaten by a Catachan, an arbites, a genestealer and by some Scions. I guess for the upgraded predator you'd need a Primaris Marine to match, they're also similarly bad written fiction.

Also, as a Star Trek Fanboy I'd say a Starfleet officer would easily deflect Bolter shots with his force field and a phaser rifle on maximum mode would punch easily through Marine armour like a Lascannon. In 40K terms though he'd probably just be a firewarrior with a 4++ invul against shooting but no armour in CC whatsoever .

Aliens are an easy one, they're simply purestrain genestealers.

I guess we need some tougher emenies, I'd like to throw in The Blob. He can only be killed by Space Wolve frost weapons, but other than that he'll nomnom all dem marines.

And

Aash wrote:
I always enjoy this sort of fun thought experiment. IMHO due to 40k's origins, most of the well known sci-fi have had some influence on the development of 40k,so for me, the easiest way to make a comparison is to find the closest equivalent in the 40k universe and compare that to a marine as a jumping off point:

Dutch and his Special Forces in Predator ≈ Catachans
Starship Troopers ≈ Guardsman
Starship Troopers Arachnid ≈ Hormagaunt
Alien Xenomorph ≈ Hormagaunt or Genestealer
Alien Queen ≈ Tyranid Warrior
Predator ≈ Lictor with a gun
T-100 ≈ Necron Warrior
Jedi ≈ Psyker Inquisitor
Light Saber ≈ Power Sword

etc.

Of course not everyone will agree with my equivalents, and how powerful each is will depend on the writer, plot armour etc, and within 40k power level varies tremendously between fluff and tabletop, and between different editions and publications.

I find it easiest rather than initially comparing things against a Space Marine, to instead start of comparing to a Guardsman, since most sci-fi settings have an equivalent (Storm troopers/clone troopers; MI from Starship Troopers etc) and see the power dynamic between the guardsman equivalent and the "other" (jedi, xenomorph, predator etc) and then see if the power difference is similar to the 40k equivalent to establish a baseline to then compare to a Space Marine.

But that's just me, probably overthinking it and getting carried away with my own head canon.

What are other sci-fi “counts as” in 40K?
Some other specific things noted are:
BattleTech Elemental being a rough equivalent to a Terminator
Starship Troopers (book) out of armor = Guardsman or Scion (I think Scion)
Starship Troopers (book) in armor = XV-8 Crisis suits

For me I would say Spartan II’s are equivalent to Space Marine Scouts… maybe give them a Rosarius for the force field?
I would say the UD-4 Cheyenne Dropship is a Valkyrie Sky Talon but carries a “Chimera” instead
That would make the M-577 APC equal to a Chimera with Multi-Laser and 2 Heavy Bolters, or maybe just a Storm Bolter

Star Trek "infantry" = IG Conscripts with no armor and a Lascannon?
Star Wars blasters = Lasguns... some are Hot Shot Lasguns?

-STS

^The Starship Troopers suits can carry nukes.

Shadows = Megarachnids? Maybe?

Dropzone/Dropfleet Commander has even worse Ripper Swarms.

MCRN Marines are a bit of a low tech equivalent of a Space Marine Aggressor. Especially Bobbi Draper.

Can't think of anything else at the moment, you seemed to have covered everything I can think of.

Based on the description of blasters, I think they'd be pulse carbines, as they shoot particles rather than lasers.


Phasers should probably have multiple profiles to reflect their ability to be programmed to work in different ways. Their most powerful setting could be lascannons, but they could also fire as a multi laser etc.

 Insectum7 wrote:
^The Starship Troopers suits can carry nukes.

What do nukes "count as"? Equivalent to a Deathstrike missile strike?
Heavy 3D6 This weapon can only be fired once per battle. This weapon can target units that are not visible to the bearer. Each time you hit the target with this weapon it suffers a mortal wound. After resolving all damage on the unit, roll a D6 for every other unit within 6" of the target unit – on a 4+ that unit also suffers D3 mortal wounds.

Looking for stats on the Megarachnid... do they have psyker powers?

 Hellebore wrote:
Based on the description of blasters, I think they'd be pulse carbines, as they shoot particles rather than lasers.


Phasers should probably have multiple profiles to reflect their ability to be programmed to work in different ways. Their most powerful setting could be lascannons, but they could also fire as a multi laser etc.

Blasters = Pulse Carbines? Well, since there are a lot different types of blasters (holdout, pistol, carbine, rifle, repeating, heavy, heavy repeating) I think you can make a case that they can go from las pistols to las cannons (for maybe the E-Web heavy repeating blaster the snowtroopers were setting up on Hoth)? Is there an equivalent weapon profile for Tau stuff?

I would think that rifle phasers can probably go from S2 D1 (for low stun) all the way up to a lascannon S9 AP-3 D6 damage... I think pistols would max out at multi-laser level? I think there are some Star Wars troops (the Rapid Reaction Teams) that have a force field shield that would be = storm shield.

Other stuff:
I would figure that Bolos would count as Titans of various sizes. An ordinatus would be closer, but not sure where those stats are in 9th...or 8th.
Colonial Marines = IG infantry with autoguns and grenade launchers and pistols.
Smartguns = heavy stubbers. Don't really think they are up to bolter standards.
Colonial Marine flamers = flamers. Shocker.

Ghost Busters proton pack = volkite blaster

Most mecha games would count as various types of Imperial Knights, but since most of them top out at about 100 tons, that would definitely keep them at Knight size, although some of them would use a lot of Tau suits like Riptides, etc. Things like transforming stuff like Cyclones or Veritechs would have a robot form, but also a vehicle speed? Figure a low size Knight like an Armiger but can also get a movement of 24" or something like that in "jet form". Smaller things like Cyclones would really just be the same thing as Bike mounted Astartes.

-STS

A nuclear weapon doesent really translate into a 40k scale weapon very well. It should just glass the entire tabletop. Even "tactical" nuclear weapons were supposed to counter whole companies or regiments of dispersed tanks.

The benefit of nuclear weapons is that you can get an awful lot of explosive potential in a small.package. if you need to damage a pinpoint target, you only need conventional.weapons.

 Hellebore wrote:
Based on the description of blasters, I think they'd be pulse carbines, as they shoot particles rather than lasers.

Strength 5 traditionally represents weapons that blow people into many pieces.
Broadly speaking a lot of sci-fi is around the strength/toughness 3-4 range - human or more than human, kill them dead(s3) or blow holes in them(s4) or blow them to bits(s5) or smoking boots(s6+).

Of course exaggeration is required if you don't want a lot of guard conscript armies.

I read somewhere that a blaster bolt is powerful enough to blow a 2m hole in a concrete wall.
Of course, that's absolutely nothing like the damage we see in films. I think it's an example of writers throwing numbers around because they sound cool, rather than them being realistic or consistent.

I do agree that hand held blasters are in the S3-4 range.

 kirotheavenger wrote:
I read somewhere that a blaster bolt is powerful enough to blow a 2m hole in a concrete wall.

From what I understand, back in the day there was some competition in internet forum circles for the 'strongest sci-fi faction' and it got to the point where fanboys were getting their own stuff into ever escalating published materials.

Force fields are actually supposed to be pretty common on Star Trek troops, though before Discovery they haven't been shown.
Star Trek overall didn't show much ground war, so its infantry weapons usually aren't that elaborated. There was one missile Launcher in insurrection but other than that I don't recall anything larger than a Phaser rifle. The only armed ground vehicle was the buggy in Nemesis which might be Patrick Stewards worst contribution to the franchise... And because of that Star Trek would easily win the Space battle against most things of 40K (remember a single Photon Torpedo has the firepower of several nukes), but concerning ground forces there's really not much there to compare. An armed runabout would probably pretty scary for most things in 40K, conparable to a Thunderhawk.

Sgt. Cortez wrote:
... And because of that Star Trek would easily win the Space battle against most things of 40K (remember a single Photon Torpedo has the firepower of several nukes)

40k starship firepower is generally described as being... excessive.
https://youtu.be/h67JpMyrOVE?t=115

 carldooley wrote:
House Lucaris
Despoiler with twin Avengers, Helm of truesight, house warlord trait.

3x2 Wardogs with autocannons

1 patrol detachment of Tsons (Duplicity) with:
1 winged DP with malefic talons, Death Hex and Warptime, Magister and your preferred warlord trait (generally +1 to cast, +1 to Invul, or +1 psychic power (treason)) (and you can use another dreadnought body to represent it), and if you want to spend a CP, the crystal relic to redeploy a unit without risking or wasting a psychic test.

1 unit of Rubrics with GoT with bodies to fill the remainder of points.

What does this get you?
A way to turn off invulnerable saves

A crapload of -2 AP shooting when you redeploy your Rubrics 9-11 inches from their targets (don't try against tau).

A really confused opponent when you use a Merchwarrior Clanner format to present your list, 'To this trial I bring 1 Assault Mech and 3 binaries of heavies, supported by 1 heavy and a handful of Elementals.'

A.T. wrote:

Sgt. Cortez wrote:
... And because of that Star Trek would easily win the Space battle against most things of 40K (remember a single Photon Torpedo has the firepower of several nukes)

40k starship firepower is generally described as being... excessive.
https://youtu.be/h67JpMyrOVE?t=115

The Enterprise did the same with its phasers once, and it was the one in the 23rd century, not D+. And this while being smaller and more maneuverable than the extremely large 40K Imperium vessels. I'd say BFG Necrons might compete with what Star Trek brings to Space.

Star Trek seems to be just as inconsistent as 40K and other fictional settings. Photon torpedoes are sometimes super destructive and at other times merely hole one compartment and damage a bulkhead. Phasers and disrupters in star trek go from atomising or vaporising someone to leaving a slight scorch mark on a bulkhead, or creating a few sparks on a rock, whatever is required by the plot, so I don’t think there’s really any way to say one is definitely more destructive than another.

Personally I’m inclined to look at the general use of something and equate it to something with a similar purpose. So, phasers are ubiquitous in Star Trek the way blasters are in Star Wars and lasguns are in 40K. They are all especially that setting’s version of a ray gun, so personally i see them as roughly similar.

Aash wrote:
Star Trek seems to be just as inconsistent as 40K and other fictional settings. Photon torpedoes are sometimes super destructive and at other times merely hole one compartment and damage a bulkhead. Phasers and disrupters in star trek go from atomising or vaporising someone to leaving a slight scorch mark on a bulkhead, or creating a few sparks on a rock, whatever is required by the plot, so I don’t think there’s really any way to say one is definitely more destructive than another.

Personally I’m inclined to look at the general use of something and equate it to something with a similar purpose. So, phasers are ubiquitous in Star Trek the way Star blasters are in Star Wars and lasguns are in 40K. They are all especially that setting’s version of a ray gun, so personally i see them as roughly similar.

This is also true. When you read the technical manual of the Enterprise it talks about how Photon Torpedos are as strong as 50nukes. And in TNG they probably were because when they hit anything without shields it was gone. Then you have later Iterations, especially Abramstrek, where they fire Photon torpedoes and you get the feeling a common hand grenade would do more damage
In 40K you see the same with a Bolter that goes from being a handheld rocket launcher to not being able to punch through Flak Armour.

Still I find these nerdtalks somehow entertaining, not the least because you hear some indepth Analysis of other universes.

Sgt. Cortez wrote:
The Enterprise did the same with its phasers once, and it was the one in the 23rd century, not D+. And this while being smaller and more maneuverable than the extremely large 40K Imperium vessels. I'd say BFG Necrons might compete with what Star Trek brings to Space.

Trek speed, durability, and firepower is whatever it needs to be for the plot on any given day. Infantry firefights in particular would be a whole lot shorter if anyone remembered they can vaporise everyone in the room, cover and all, with their first shot.

Sgt. Cortez wrote:
This is also true. When you read the technical manual of the Enterprise it talks about how Photon Torpedos are as strong as 50nukes.

'Nuke' isn't a measure of power.

Halo’s Spartans would be Marines with iron Halos (to account for their shields). I’ve only played the original Halo, and wouldn’t consider Master Chief a scout Marine at the least.

Also, while it’s clear that the xenomorphs of the alien franchise map directly to genestealers, don’t forget they have acid blood and “sample” their host to assimilate some of their prey’s attributes to hunt it down better. A xenomorph born from a marine host could be a terrifying thing...

As for Star Trek, I would dismiss anything from Discovery. I don’t think we saw ground forces until late TNG or DS9 and they did not use personal force fields* - I think at best they set up force screen projectors to protect a static area - like a 40k Vortex Shield generator.

* I think on Voyager they may have developed them from borg tech to face the borg, but the last season or two of that show is muddled in my memory.


Automatically Appended Next Post:
Also, wouldn’t predators make to Eldar striking scorpions, with the plasmacasters being mandiblasters?

Upon a time I used Noble Team from Halo: Reach as a basis for Sanguinary Priests in a Blood Angels list. Warthogs from actionclix as Las\Plas Razorbacks, Stormravens as Pelicans, and Land Speeder Typhoons as Falcons.

I wasn't a fan of the dreadnought in the army, but they got a lot more palatable when I replaced the standard stumpy legs with the chicken legs of a Sentinel. If I was going to make the army again, I would likely just ally in some Armigers instead.

Sgt. Cortez wrote:

Aash wrote:
Star Trek seems to be just as inconsistent as 40K and other fictional settings. Photon torpedoes are sometimes super destructive and at other times merely hole one compartment and damage a bulkhead. Phasers and disrupters in star trek go from atomising or vaporising someone to leaving a slight scorch mark on a bulkhead, or creating a few sparks on a rock, whatever is required by the plot, so I don’t think there’s really any way to say one is definitely more destructive than another.

Personally I’m inclined to look at the general use of something and equate it to something with a similar purpose. So, phasers are ubiquitous in Star Trek the way Star blasters are in Star Wars and lasguns are in 40K. They are all especially that setting’s version of a ray gun, so personally i see them as roughly similar.

This is also true. When you read the technical manual of the Enterprise it talks about how Photon Torpedos are as strong as 50nukes. And in TNG they probably were because when they hit anything without shields it was gone. Then you have later Iterations, especially Abramstrek, where they fire Photon torpedoes and you get the feeling a common hand grenade would do more damage
In 40K you see the same with a Bolter that goes from being a handheld rocket launcher to not being able to punch through Flak Armour.

Still I find these nerdtalks somehow entertaining, not the least because you hear some indepth Analysis of other universes.

When I think of Star Trek starship weapon power levels, I will always default to Wrath of Khan or the other original cast movies. Anything that gets through shields, whether it's phasers or photon torpedos , is pretty devastating. Pretty much any time a photon torpedo lands a solid hit, that area of the ship is removed, if not the whole ship obliterated. It's why they have the actors really panic when shields are close to failing. Shoot, now I gotta watch Wrath of Khan for like the 100th time.

Gonna change my opinion on the UD-4 from Aliens...going to say it counts as a Thunderhawk.

The Aliens APC weighs ~16 tons fully loaded. The Thunderhawk can carry 30 space marines...and a space marine in armor weighs (on the low side) 500kg. That would allow a Thunderhawk to haul 15,000 kg or a bit over 16 tons.

-STS

Trek weapons are pretty sad as far as Sci-Fi weapons go. If you want details here are a few well-written essays about the onscreen effects we see Trek weapons achieve.

Torpedos: http://stardestroyer.net/Empire/Tech/Torpedoes/Torpedo1.html

Phasers: http://stardestroyer.net/Empire/Tech/Beam/Beam1.html

Power Generation: http://stardestroyer.net/Empire/Tech/Power/Power1.html

Other Tech: http://stardestroyer.net/Empire/Tech/Special/Special1.html

 Canadian 5th wrote:
Trek weapons are pretty sad as far as Sci-Fi weapons go. If you want details here are a few well-written essays about the onscreen effects we see Trek weapons achieve.

Torpedos: http://stardestroyer.net/Empire/Tech/Torpedoes/Torpedo1.html

Phasers: http://stardestroyer.net/Empire/Tech/Beam/Beam1.html

Power Generation: http://stardestroyer.net/Empire/Tech/Power/Power1.html

Other Tech: http://stardestroyer.net/Empire/Tech/Special/Special1.html

I generally just take Trek at their highest calcs and that still makes them only barely equivalent to small 40k capital ships. I think most Trek ships cap out around Destroyer level in 40k. I would think that the Star Wars vaunted Star Destroyer is just a Destroyer in 40k. That would mean it takes Battleships in Star Wars to get to Cruiser level in 40k.
Star Trek = Star Wars = 40k
fighters = fighters = fighters
small craft = freighters = dropships
Support ships = heavy freighters = small freighters
Science ships (what everyone else calls small capital ships or Corvettes) = Corvettes/Frigates = Corvettes
Escorts = Destroyers/Frigates = Corvettes
Cruisers = Cruisers = Corvettes/small destroyers
Explorers (what everyone else calls a battleship) = Battleships = Destroyers

40K has some really OP ships comparatively, although their capability to maneuver is far less than Star Trek ships, and Star Wars ships seem to carry just as many fighters as 40k ships (~6 squadrons each) while Trek ships have like some runabouts? Trek has far better fire control, but once their shields go, the ship is pretty well doomed. Plus, Star Wars and 40K seem funny capable of boarding actions, while Star Trek does have transporter technology, they don't seem to really make full use of boarding as a normal tactic.

-STS

slade the sniper wrote:
I generally just take Trek at their highest calcs and that still makes them only barely equivalent to small 40k capital ships. I think most Trek ships cap out around Destroyer level in 40k. I would think that the Star Wars vaunted Star Destroyer is just a Destroyer in 40k. That would mean it takes Battleships in Star Wars to get to Cruiser level in 40k.

You're woefully undervaluing the sheer firepower that Star Wars ships can throw around.

By the low-end calculations done by analyzing the films*, the light guns on a Star Destroyer are putting out energy equal to both Little Boy and Fat Man combined per shot. In canon sources, such as the ICS books** we get figures of 6 megatons (~17 times more energy output) for the light guns on a simple troop transport with their heavy weapons in the 200 gigaton range. A proper ISD has a far larger reactor and thus could easily be an order of magnitude more powerful than that.

*See this and this for my source for these figures.
**Specifically: Star Wars: Attack of the Clones Incredible Cross-Sections

 Canadian 5th wrote:

slade the sniper wrote:
I generally just take Trek at their highest calcs and that still makes them only barely equivalent to small 40k capital ships. I think most Trek ships cap out around Destroyer level in 40k. I would think that the Star Wars vaunted Star Destroyer is just a Destroyer in 40k. That would mean it takes Battleships in Star Wars to get to Cruiser level in 40k.

You're woefully undervaluing the sheer firepower that Star Wars ships can throw around.

By the low-end calculations done by analyzing the films*, the light guns on a Star Destroyer are putting out energy equal to both Little Boy and Fat Man combined per shot. In canon sources, such as the ICS books** we get figures of 6 megatons (~17 times more energy output) for the light guns on a simple troop transport with their heavy weapons in the 200 gigaton range. A proper ISD has a far larger reactor and thus could easily be an order of magnitude more powerful than that.

*See this and this for my source for these figures.
**Specifically: Star Wars: Attack of the Clones Incredible Cross-Sections

How do these calcs compare to 40K? I know there is a LOT of fluffing of numbers in the fandoms for ST, SW and 40K and that is fine, but for me, that is how I arrange the power levels by franchise. What is your power scale/equivalent by franchise? That is more what I am interested it. What are your "counts as?"

I am NOT discounting your numbers, but in comparison to 40K, Star Wars ships (if brought into BFG) are not going to be something that any of the big factions are going to be scared of. Even the Death Star is just a theatrical Exterminatus. It isn't until you get into Sun Crusher or Starkiller Base territory, that the Imperium would notice...and the Aeldari (and their offshoots) and Necrons have things that can match that.

-STS

slade the sniper wrote:
How do these calcs compare to 40K? I know there is a LOT of fluffing of numbers in the fandoms for ST, SW and 40K and that is fine, but for me, that is how I arrange the power levels by franchise. What is your power scale/equivalent by franchise? That is more what I am interested it. What are your "counts as?"

There is no number fluffing required for Star Wars, the numbers for capital ship firepower are literally canon and thus require no calculation.

For 40k, as with most things, it depends on what even you're looking at. If you want a deep dive feel free to read the resources located here.

One good thread is [url=http://bbs.stardestroyer.net/viewtopic.php?t=112996&postdays=0&postorder=asc&highlight=40k&start=0]this one

We see Star wars ships being destroyed by small single crew 'aircraft' multiple times.
We also see their lasers being fired and the results aren't anything close to a nuclear bomb detonation.

This is a problem with sci-fi, an author prints a cool number with zero consideration of what the number means, which ends up being very far away from what appears elsewhere.
So which do you take as canon?

 kirotheavenger wrote:
We see Star wars ships being destroyed by small single crew 'aircraft' multiple times.

In almost every one of those cases, the ship in question had already been battered into submission before the fighters moved in for the kill. In the most famous example, the Executor was taking fire from most of the rebel fleet before the A-Wing that crashed into the bridge caused it to misfire its engines and slam into the second Death Star where it met its end. In other cases, we see the fighters flying under the shields of a capital ship and picking off exposed weapon emplacements.

Can you show me an example where neither of these scenarios are in play?

We also see their lasers being fired and the results aren't anything close to a nuclear bomb detonation.

Except when we see them vaporizing 40m asteroids, blowing up planets, one-shotting capital ships, melting the surfaces of worlds until they're covered in meters deep layers of magma, causing stars to go supernova, blowing up planets at multiple lightyear distances, and other examples of exactly that kind of firepower. A simple bounty hunter is able to get blasters able to fragment asteroids the size of his ship and bombs and missiles able to do the same to asteroids hundreds of meters across. These aren't easy feats to accomplish.

In all fairness, both Star Wars and Star Trek are monstrously inconsistent, even across print sources, much less visual displays.

The Executor sees a couple fighters get in close and zap a shield array, then has one slam into the bridge, seemingly causing a complete system failure with zero backup control for it to slam into a massive object and explode. Meanwhile Mon Calamari Turbolasers seemed to to...largely nothing. The Deathstar meanwhile would have instantly killed everyone on board and shredded the entire station many times over for it to have the done what was displayed of Alderaan blowing up.

Star Trek Photon Torpedoes are noted as having antimatter warheads, and we've seen them do as little as something like a mortar or light artillery shell (e.g. Star Trek V) with characters surviving hits from just a few dozen meters away (seemingly with less energy than their kinetic reentry alone would imply), to obliterating areas the size of nation states. We've seen them hit ships without shields and simply poke holes in them (e.g. Star Trek VI) or instantly obliterate them in others. In fact in STVI we see a cloaked (shields down) Bird of Prey require multiple direct Photon Torpedo hits to destroy (after the first lights it up), and then in DS9 the exact same ships, uncloaked, are destroyed by a single hit from torpedos launched by the station.

Much like 40k, none if its mean to be realistic or consistent, but to serve a narrative

 Vaktathi wrote:
The Executor sees a couple fighters get in close and zap a shield array, then has one slam into the bridge, seemingly causing a complete system failure with zero backup control for it to slam into a massive object and explode. Meanwhile Mon Calamari Turbolasers seemed to to...largely nothing. The Deathstar meanwhile would have instantly killed everyone on board and shredded the entire station many times over for it to have the done what was displayed of Alderaan blowing up.

"Fleeing the Death Star's firepower, the Rebels engaged Piett's Star Destroyers at close range while their ground assault team destroyed the shield generator protecting the superweapon, allowing the Rebel fighters to fly into its superstructure. The Alliance Fleet commander, Admiral Gial Ackbar, wishing to buy more time for the fighters to accomplish their mission, ordered a concentrated barrage against the Executor. As the Alliance warships focused their fire on the Super Star Destroyer, two RZ-1 A-wing interceptors strafed the Executor's bridge deflector shields, bringing them down. In response, Piett ordered the forward batteries to intensify their firepower to prevent anything from penetrating the window of opportunity.[7]

Aware that the Executor would become the fulcrum of not only the battle but also the balance of power in the entire Outer Rim, Vice Admiral Rae Sloane moved her ship, the Vigilance to flank position on the Executor to try and defend it.[33] However, Rebel Green Leader Arvel Crynyd, with his A-wing starfighter badly damaged by fire from the Executor, managed to retain just enough control of his stricken ship to send it towards the Imperial vessel's unshielded bridge. Seeing the threat, Piett once again shouted to intensify the forward batteries, but, as Commander Gherant realized, it was too late; the Rebel fighter crashed into the Executor command tower. As explosions engulfed the bridge, the massive ship listed to port and plunged towards the Death Star's surface, exploding upon impact.[7]"

That 'nothing' the capital ships were doing was battering down the ship's extremely heavy shielding so the fighters could make effective attack runs.

Quotes from the novelization:

ROTJ Novelization wrote:An aide approached Ackbar. 'We've added power to the forward shield, Admiral.'

'Good. Double power on the main battery,' and- Suddenly the Star Cruiser was rocked by thermonuclear fire works
outside the observation window.

'Gold Wing is hit hard!' another officer shouted, stumbling up to the bridge.

'Give them cover!' Ackbar ordered. 'We must have time!' He spoke again into the comlink, as yet another
detonation rumbled the frigate. 'All ships, stand your position. Wait for my command to return!'

ROTJ Novelization wrote:An aide handed Ackbar the comlink. General Calrissian's voice was coming through.

'Home-one, this is Gold Leader. That blast came from the Death Star! Repeat, the Death Star is operational!'

'We saw it,' Ackbar answered wearily. 'All craft prepare to retreat.'

'I'm not going to give up and run!' Lando shouted back. He'd come a long way to be in this game.

'We have no choice, General Calrissian. Our cruisers can't repel firepower of that magnitude!'

'You won't get a second chance at this, Admiral. Han will have that shield down - we've got to give him more
time. Head for those Star Destroyers.'

Ackbar looked around him. A huge charge of flak rumbled the ship, painting a brief, waxen light over the
window. Calrissian was right: there would be no second chance. It was now, or it was the end.

He turned to his First Star captain. 'Move the fleet forward.'

'Yes, sir.' The man paused. 'Sir, we don't stand much of a chance against those Star Destroyers. They out-gun
us, and they're more heavily armored.'

'I know,' Ackbar said softly.

The captain left. An aide approached.

'Forward ships have made contact with the Imperial fleet, sir.'

'Concentrate your fire on their power generators. If we can knock out their shields, our fighters might stand
a chance against them.'

So your take is just wrong, entirely.

Oh I love books retconning in detail that simply didn't exist in the films. It just really tickles me for some reason.
That's 100% not what happened in tbr film. In the film, Ackbar orders concentrate firepower on the Executor.
Not half a second later, two A-wings strafe the shield generators and destroy them (lesson 1, Star destroyers are super vulnerable to even light interceptors). We don't see any battering of the Executor from.capital ship fire, none.
Then, just a few seconds after that, an out of control A-Wing smashes into the bridge and destroys the ship loses all control (lesson 2, Star destroyers are super vulnerable to even light aircraft impacts).

The capabilities of these weapons are driven by literally nothing more than plot convenience. It's impossible to pin down an exact capability because it's so inconsistent.