Modern soldiers vs. Faerun. What do you think happens?

[Jeivar]

I don't know why, but I suddenly started wondering: Obviously modern soldiers would slaughter an ordinary 15th Century force of knights and footmen, but how much of a game-changer is D&D magic? If, say, an infantry battalion attacked one of the larger cities of Faerun, or a regiment went to war with one of the notable nations, what would happen? I'd say bullets beat magic missiles, but getting into less straightforward combat, then magic can pull of some neat tricks, like mind control, teleportation, and summonings, just to name a few.

If a spellcaster summons something that can only be harmed by magic, then the modern soldiers aren't going to have any way of dealing with it. But just how common is medium-to-high-level magic in the Forgotten Realms, anyway? How would enchanted plate fare against rifle rounds?

Basically, how do you think these scenarios would play out?

[dancrilis]

Comparing d20 Modern with DnD 3.5, I think the modern soldiers get slaughtered.

Effectively a Barrett M82 does 2d12 damage or an average of 13 damage, that is not enough to kill a first level commoner (4hp) in one shot on average (people will bleed out 90% of the time), a Desert Eagle does 2d8 damage average 9 damage it takes a commoner (4hp) down to -5 damage that means ~60% chance of death.

Effectively on those figures modern soldiers are effectively low hit point creatures armed with weapons that can happily take down low hit point creatures - but they will not last well against even mid level adventurers let alone anything high level.

[Razade]

D&D magic can summon invincible walls of energy or fire or stone. It can summon food from nowhere and heal wounds better than anything, and faster, than we can do along with inflicting awful curses and summoning monsters that even modern people would have a problem with. A modern force of soldiers with no supply lines back to Earth or anywhere in the country against say....Halruaa is going to be devastated.

It's not even a fair fight.

[Palanan]

Originally Posted by Jeivar
But just how common is medium-to-high-level magic in the Forgotten Realms, anyway?

The Realms are pretty famous for having high-level casters hiding under every bush. That’s an overstatement, of course, but simply flipping through a few random pages of the FRCS gives me mid- to high-level casters on nearly every page.* And those are just the named characters.

Your infantry battalion might hold out for a while in a less-populated area, but if they’re throwing themselves against even a moderate settlement, then it’s flaming spheres and thoqquas setting them on fire and cooking off their ammo, interspersed with lighting, flame strikes, and drifting clouds of poisonous gas.

The only way these guys could survive is to go native—first by making the mental adjustment that this is really magic, and then by somehow managing to get some for themselves. But that would be a steep, steep learning curve, and if they’re under any kind of concerted attack, the only survivors will be the ones who ran first…and that’s if the werewolves don’t get them.


*Plus one Ftr20/Rog3/Wiz7, of all things, but that's the Realms for you.

[Anteros]

Modern soldiers are going to have far better tactics, supplies, numbers, and basically every other advantage that matters in a fight. They'd absolutely roll over everything until they run up against higher end magic at which point they can do nothing and get slaughtered.

[Kitten Champion]

I don't think mundane bullets beat magic missile. Not when you consider that magic missile has an infinite supply and literally never misses. You can also strike several Creatures with one casting.

I wouldn't say bullets are purely worse - you can use more of them, over a larger range, and you don't need to be in someone's range of vision to use them technically - but there are trade offs there.

[NigelWalmsley]

D&D offensive magic is actually not that impressive at the battlefield level. A Fireball is great when you're fighting Orcs in a dungeon, but it's actual radius and effect are not that much more impressive than an grenade, and the number of Fireballs even a relatively elite Wizard can produce is not that much larger than how many a soldier can carry. And the Wizard needs to rest and prepare spells to get more Fireballs, while the soldier can just go get more grenades. Even high level offensive magic is mostly about getting ever more overwhelming firepower (to keep up with the HP and defenses of high level monsters) rather than effecting larger numbers of targets. Wail of the Banshee kills high level enemies instantly, but it does so in an area that is still pretty small on the scale of battles.

That said, there are spells that are more useful. The big one (as is often the case) is Planar Binding. A Wizard running around personally casting Fireball can only do so maybe two dozen times in a day, and is quite vulnerable to tanks, artillery, or even snipers while doing so. But the Wizard doesn't have to fight that way. He could instead go bind up a bunch of Glabrezus. Those guys have blasting that is as good or better than Fireball, but they can use it as often as they want. And they can Teleport, and are resistant or immune to most stuff infantry can throw at them (depending on how you stat guns). Similar results can be produce by a Wizard who simply layers a large number of buffs and defensive spells on himself.

But the real gamechanger is that there's no reason for Team D&D to give pitched battle at all. Magic isn't very good at murdering armies. But it's great at infiltrating heavily fortified compounds and murdering everyone inside. And while that doesn't describe an army, it does describe basically every authority figure in the world. An army might focus-fire down a Wizard, but there's no way for the Secret Service to bring enough firepower to bear to stop an adventuring party from running roughshod over the White House.

So I would expect the first battles to be pretty ruinous for Team D&D as they are made familiar with concepts like "indirect fire artillery" and "close air support". But I would expect them to adapt fairly rapidly thereafter, as they discover that while the armies they're facing are deadly, they're in no way prepared to deal with Teleport-based warfare and are lead by people with maybe three hit dice. So the war probably ends with the Wizards repeatedly assassinating any political, economic, military, or religious leader who gets appointed until someone surrenders.

[Forum Explorer]

Depends on the edition. D20 Modern is not reality (a gun can easily kill an Elephant in a single shot, a D20 gun will not reliably kill a single person), so I wouldn't use it as a basis of comparison.

In reality, a solider can shoot his gun much faster than a D&D character can attack and at much much further ranges. A bullet would likely do thirty+ damage a shot. Which brings us back to which edition is it? In 3.5, simply doing a bunch of damage isn't enough. Magic is too OP. But 5e? Magic isn't nearly as crazy. Limited buffs, limited summons, limited disables.

Also Faerun only has limited mages. So unless they showed up in Thay or Waterdeep, there likely wouldn't be all that many mages to fight against the modern army, and I think only spellcasters would have a chance.

[Palanan]

Originally Posted by Anteros
Modern soldiers are going to have far better tactics, supplies, numbers, and basically every other advantage that matters in a fight.

I don’t think they’d have the advantage in any of these areas.

Modern soldiers operate using tactics developed to help them defeat other modern soldiers, not xorn and thoqquas. They’ll be on Faerûn, so without any logistical support or backup from home, and no GPS or other benefits of our world’s infrastructure. And while an infantry battalion might have about a thousand soldiers, that’s a very small force when compared to a full army.

Originally Posted by Anteros
They'd absolutely roll over everything until they run up against higher end magic at which point they can do nothing and get slaughtered.

The OP did specify that the battalion would be attacking one of Faerûn’s larger cities. As an example, Silverymoon is listed as a “metropolis” with 37,073 inhabitants—and that includes an 18th-level wizard, a 12th-level wizard, a 13th-level cleric, nine clerics of 8th-10th level, and twenty-five additional wizards between 5th and 11th level. That’s also including a number of sorcerers, paladins, and rangers between 5th and 10th level.

So, if Silverymoon is their first target, they’re instantly up against ninth-level spells, plus a great mass of all the other spells. I won’t do the math, but that’s probably several hundred magic missiles in the first seconds of hard contact. I don’t see this fight lasting long.

[NigelWalmsley]

Depends on the edition. D20 Modern is not reality (a gun can easily kill an Elephant in a single shot, a D20 gun will not reliably kill a single person), so I wouldn't use it as a basis of comparison.

I mean that seems pretty realistic? Lots of people survive gunshot wounds. Most places you can get shot, even ones that are fatal eventually, won't kill you particularly quickly.

But 5e? Magic isn't nearly as crazy. Limited buffs, limited summons, limited disables.

Magic is limited. But magic users (and adventurers in general) are still dramatically more powerful than any individual person in a real-world army. You might beat Team D&D in the field, but your officer corps is going to get absolutely decimated, let alone whatever political leaders are in charge in whatever country you're from (assuming that's a factor here).

[Mr_Fixler]

Modern military began to ditch the "let's throw ground troops at the base or battlefield until we win" approach over one hundred years ago though.

I get that magic is a game changer, but so are mortars, sniper teams, helicopters, drones, jets, missiles, etc. These all working in tandem as true modern military engagement? I think that it could give those adventurers a run for their money.

Not saying a stomping but this didn't the civil war era tactics and military.

[Palanan]

Originally Posted by Forum Explorer
Also Faerun only has limited mages.

What.

Silverymoon has at least 37 wizards and clerics between 5th and 18th level, and that’s not counting the other spellcasting classes. That’s one mid-to-high-level cleric or mage for every thousand citizens.

As another example, selected at random, Uthmere (pop. 8820) has five wizards between 5th and 11th level, plus five clerics, four sorcerers and four druids in that level range. Again, that’s one mid-to-high-level cleric or mage for every thousand citizens, plus the sorcerers and druids.

Uthmere is much smaller than Silverymoon, and the infantry battalion might make more progress there, but again the OP specified an attack against a larger city. And even a small city like Uthmere has over a hundred casters overall, which in urban fighting on home ground will be a substantial impediment.

[Lord Raziere]

Well its faerun so.....modern soldiers stomp medieval warriors until either a bunch of wizards figure out a way to stop the bloodshed/win, or the modern military somehow kills them until and keep going until they collectively tick off the gods who respond with a continent/worldwide apocalypse to wipe the board clean and make it clear to never come back here ever again if they know whats good for them and the modern soldiers are sent running for their lives while the faerunians breath a sigh a relief at everything going back to normal and keep adventuring as if its a normal tuesday.

[Huzuhbazah]

Elminster conjures uranium-235 while inside of a resilient sphere, and Earth resigns.

[Mechalich]

The key here is that high-level spellcasters, levels 15+, are, with proper optimization and tactics, in 3.X D&D, effectively gods. They can, with only a modicum of prep time, utilize nigh-infinite extraplanar resources to do anything they want.

Now, counterpoint, is that if they do this at all, the Forgotten Realms collapses. Existing descriptions of high-level spellcasters engaging armies are mostly based on 2e capabilities (ex. Aulustriel of Silverymoon fights the drow army in Siege of Darkness, the actions attributed to here by RA Salvatore are not impressive) and would easily be matched by the capabilities of a modern 21st century armed force with the full might of its technological components.

And, of course, there's the great unanswered question of what happens when you stack a nuclear weapon against various high-level protection spells. Nobody knows if a Prismatic Sphere or anything else would protect you in said circumstances (nukes explicitly exist in D&D, Jeff Grubb wrote a short story where a Tinker Gnome invented one).

[Palanan]

Originally Posted by Mr_Fixler
I get that magic is a game changer, but so are mortars, sniper teams, helicopters, drones, jets, missiles, etc.

OP specified an infantry battalion, which probably won’t have jets. Helicopters and drones are another matter, but that depends on the OP.

[Forum Explorer]

I mean that seems pretty realistic? Lots of people survive gunshot wounds. Most places you can get shot, even ones that are fatal eventually, won't kill you particularly quickly.



Magic is limited. But magic users (and adventurers in general) are still dramatically more powerful than any individual person in a real-world army. You might beat Team D&D in the field, but your officer corps is going to get absolutely decimated, let alone whatever political leaders are in charge in whatever country you're from (assuming that's a factor here).

There is a big difference between a hunting rifle, and a .50 calibur bullet. The .50 will pretty much amputate limbs if it hits you. Which I'd say is a lot more than just 2d12 damage.

Well not really that much. It's not like armies are slow. Or fight in the field. A modern army could be bombarding a city within a day, and leveling any building that looks important before eight hours are up. While still being tens of thousands of meters away. Also Faerun isn't that high powered of a setting. A massive horde of orcs is a legitimate threat there.

[Saintheart]

There is a big difference between a hunting rifle, and a .50 calibur bullet. The .50 will pretty much amputate limbs if it hits you. Which I'd say is a lot more than just 2d12 damage.

Which brings us to the problem inherent in the question, which is: is the Big Red One playing by D&D 3.5 mechanics, or is Faerun playing by real-world Earth physics?

Either way I think the infantry battalion has problems if Faerun is given the least chance to prepare for any sort of assault. Persistent Spells and therefore the CoDzilla were basically invented in Faerun, or at least that's where the metamagic was first published. Contingent Spells mean you're not taken unaware. Teleport gets you to within 30 feet of the enemy, and if you have Friendly Fire up, the infantry battalion starts shooting itself while the high level caster stands there smoking an implausibly long pipe.

[The Glyphstone]

Faerun exists in a status quo where stuff like orc hordes can be dangerous largely because the good and evil gods, and by extension their mortal champions, tend to stay out of it or cancel each other out. Throw in a third team of extradimensional tech using invaders and all bets are off.

[Mechalich]

Faerun exists in a status quo where stuff like orc hordes can be dangerous largely because the good and evil gods, and by extension their mortal champions, tend to stay out of it or cancel each other out. Throw in a third team of extradimensional tech using invaders and all bets are off.

I mean, not really. The Return of the Archwizards trilogy actually describes a third team of extradimensional invaders - specifically about 200 Phaerrim released from behind the Sharn Wall and their thousands of enslaved beholders - and while the resulting war encompasses multiple Chosen of Mystra, Evereskan High Mages, and Princes of Shade the descriptions are startlingly conventional and painfully anti-optimized (for instance, I don't think anyone, on either side, summons anything).

The people who made the Forgotten Realms did so with a very, very different idea of what high-level full casters were capable of compared to 3.5e D&D. Ed Greenwood, Troy Denning, Jeff Grubb, Elaine Cunningham, RA Salvatore, and others worked off a 1e and 2e model where casters simply weren't that powerful compared to everyone else, had specific vulnerabilities that could be exploited, and power boosts like metamagic simply did not exist.

For example, in Siege of Darkness, Silverymoon dispatches forces to Mithril Hall to fight the Drow invasion. Specifically they send two hundred mounted knights and also Aulustriel herself. Salvatore actually values the knights more than Aulustriel, which in a 3e context would be absurd.

The overall problem is that the Realms simply doesn't work when converted to 3e rules, there are simply too many high-level casters for the setting to not tear itself apart

The question of a 21st combat unit invading the 2e or 5e Realms is much more interesting. I suspect in that case they would initially do very well, and might in fact take whatever city they invaded, but that the various high-level casters and urban monsters (Steel Dragons, etc.) would easily escape using magic and would then be able to wage a very successful guerilla campaign to retake the city over the next few weeks by gradually grinding down the enemy force once they had a grasp of the invaders tactical capabilities.

[kinem]

I just want to point out that combat in D20 Modern works differently than in D&D, which is one of the reasons that despite WotC's claims to the contrary the two systems are not able to interact well.

The main difference is that in D20 Modern, the Massive Damage threshold is the creature's Con score, as opposed to 50 in D&D. That means that even most skilled warriors are at risk from most attacks. This leads to more realistic, anti-D&D behavior such as preferring to avoid combat.

As a result, D20 Modern modules can't function properly under D&D rules, just as D&D characters can't function properly under D20 Modern rules.

[Saintheart]

The overall problem is that the Realms simply doesn't work when converted to 3e rules, there are simply too many high-level casters for the setting to not tear itself apart.

I think the Realms doesn't work in 3e if you assume optimised or particularly strategic casters. I grant you that most of the book casters are built such that it's easy to conclude their INT score has no crossover whatsoever with actual brains, but the books were basically written back when WOTC thought direct damage was a thing. I find reading the books and statblocks of FR 3e is a less eye-gouging experience if you tell yourself that everyone with a casting ability in the Realms has signed up to a gentleman's agreement that nobody will imperil the action economy.

[Mechalich]

I think the Realms doesn't work in 3e if you assume optimised or particularly strategic casters. I grant you that most of the book casters are built such that it's easy to conclude their INT score has no crossover whatsoever with actual brains, but the books were basically written back when WOTC thought direct damage was a thing. I find reading the books and statblocks of FR 3e is a less eye-gouging experience if you tell yourself that everyone with a casting ability in the Realms has signed up to a gentleman's agreement that nobody will imperil the action economy.

FR is a fundamentally an AD&D creation. While Ed Greenwood started working on it before D&D was really even a thing, it got incorporated in the greater framework in the AD&D era under TSR. Consequently the way casters acted was based around a set of assumptions keyed to how the rules for the first two editions of AD&D worked (which were ultimately quite similar). It's very clear in the narrative novels. Elminster has a distinctive casting combat style and it's remained largely unchanged since he first appeared in Spellfire back in 1988. The Realms still doesn't properly reflect how powerful casters are under 2e AD&D rules, precisely, but it's much, much closer, especially on the divine side (all of the Realms' big names are wizards because wizards were flat out more potent casters in 2e).

[Bullet06320]

https://old.reddit.com/r/AskReddit/c...empire_during/

interesting read on a marine unit traveling back in time to the romans

in the realms, electronics and gunpowder dont work that come from other worlds

from the original campaign setting box set, DMs source book of the realms pg

The physics of the Realms are slightly out of sync with the rest of the planes, so that gunpowder and many technological devices which operate on electronics do not function. Equivalent devices may be developed by player-characters. DM's judgment is advised as to what may be allowed into the world.

not 100% sure if that carries over to other editions without alot of bookdiving

so possibly from the get go, no gas, no working weapons, but assuming they work, you have limited supply and no way to get more easily, given time and modern knowledge, its possible

no gps regardless, as no satalites to work with

if it all works, has an advantage at range and tactics, due to no one knowing how to kill a modern tank or helicopter, long term tho, once ammo and gas runs out, armies and wizards doing it their way win, modern solders dont have appropiate armor to deal with swords and axes, and magic is just simply too big a factor to discount at any time. especially in the realms where there is a wizard of some sort behind every bush

politics is another factor, the zhents, redwizards, arcane botherhood, and dozens of others might try to make friends to get a peek at the technology to get it for themselves. or try and steal it.

im voting on modern soldiers losing

[Khedrac]

Elminster conjures uranium-235 while inside of a resilient sphere, and Earth resignslaughs.

Nuclear weapons are hard to get to work properly. Elminster has more kowledge of Earth than probably any oher D&D character (canonically he has spent quite a bit of time there at Ed Greenwood's house) so he is actually likely to be aware of the potential of radioactive materials. The problem with your suggestion is that the probable result is "fizzle" not "bang" (and it it does manage to go "bang" it probably counts as a disintergration effect and will go through the sphere). The local effect will be bad (radioactive contamination and a lot of local damage, but apart from the long-term contamination Elminster has better ways of having more effect than playing around with something he doesn't understand.

Over the decades I have come across multiple stories of parties using control wind or similar to make a centrifuge to make heavy water and from there nuclear weapons and it simply would not work.

Step 1 - you need to catch the heavy material from your centirifuge which is probably the part you are throwing away.
Step 2 - unless you have purfied the water first all you will get is the contaminents
Step 3 - purify water will remove the dueterium-based water (it's poisonous) so don't try that method.
Step 4 - you need D20, but all you will get out is HDO - you need to split the water and get it to re-combine a lot to make some D20 that you will need to re-filter out again.

Get any of those steps wrong (and how do the characters even know to try) and you are not getting to the starting point

[Forum Explorer]

What.

Silverymoon has at least 37 wizards and clerics between 5th and 18th level, and that’s not counting the other spellcasting classes. That’s one mid-to-high-level cleric or mage for every thousand citizens.

As another example, selected at random, Uthmere (pop. 8820) has five wizards between 5th and 11th level, plus five clerics, four sorcerers and four druids in that level range. Again, that’s one mid-to-high-level cleric or mage for every thousand citizens, plus the sorcerers and druids.

Uthmere is much smaller than Silverymoon, and the infantry battalion might make more progress there, but again the OP specified an attack against a larger city. And even a small city like Uthmere has over a hundred casters overall, which in urban fighting on home ground will be a substantial impediment.

37 is pretty limited. Particularly when levels 5th to oh, I can't quite remember (and it depends on edition to boot) 12 I think are basically cannon fodder. From what I remember from that chart there is exactly 1 mage that can cast level 9 spells in a place the size of Silverymoon.

Honestly though, a preliminary bombardment or bombing, targeting important look buildings (like temples and wizard towers) would be devastating. Combined with snipers set up to target important people leaving the city, and most of those mages would be wiped out day 1. The really high level ones might still be around, but those are the level 15 and higher which is more like 3-4 mages total.

Which brings us to the problem inherent in the question, which is: is the Big Red One playing by D&D 3.5 mechanics, or is Faerun playing by real-world Earth physics?

Either way I think the infantry battalion has problems if Faerun is given the least chance to prepare for any sort of assault. Persistent Spells and therefore the CoDzilla were basically invented in Faerun, or at least that's where the metamagic was first published. Contingent Spells mean you're not taken unaware. Teleport gets you to within 30 feet of the enemy, and if you have Friendly Fire up, the infantry battalion starts shooting itself while the high level caster stands there smoking an implausibly long pipe.

Is Faerun playing by 3.5 rules instead of any other edition? After all, the current timeline does have them at 5e rules I believe. But yes, that is the big question. If it is 3.5, than yeah, I think Faerun wins eventually. Buuuuuut, Faerun doesn't really run on optimized 3.5 rules. I mean, the Return of the Archwizards series is pretty much all about high level mages waging wars and they use pretty simplistic tactics. No summoning, no Ice Assassins, very few save or lose spells. It's mostly just the classic blaster mages.

[GloatingSwine]

I don't think mundane bullets beat magic missile. Not when you consider that magic missile has an infinite supply and literally never misses. You can also strike several Creatures with one casting.

I wouldn't say bullets are purely worse - you can use more of them, over a larger range, and you don't need to be in someone's range of vision to use them technically - but there are trade offs there.

I think you're underestimating the range (and lethality) difference.

Magic Missile has a 120' range. The effective range of a designated marksman rifle (one per squad, usually) is 250-300 yards. That's about ten times the effective range. Note, that's not a sniper, those are very different beasts (and will be used against wizards).

Every wizard who isn't able to astrally project themself from a pocket plane is going to get a case of sudden exploding chest syndrome from weapons fired over a mile away.

Meanwhile, rifle rounds are, due to their high velocity, absolutely horrible to the insides of fleshy bodies (speed of passage creates an internal void which then collapses on itself shredding all the tissues inside). Even nonfatal shots are absolutely debilitating (generally going into shock)

Modern (as in post-WWII) soldiers also have a training advantage, which is that they are conditioned to kill. The way modern training works is that it gives a very short period of time to fire at a human shaped silhouette, which means that modern soldiers are conditioned to reflexively shoot at human targets, overcoming the natural resistance to actually shoot a fellow person. As late as World War 2 only 2% of soldiers actually fired their weapon at another person, they would fire in the general direction of enemies, but very few fired with intent to kill because most humans just don't do that. Modern training shortcuts that by making shoot-to-kill into a reflex.

There's also the psychological effect of multiple forms of contact. Every different way an enemy is attacking you is called a "form of contact", and the more forms of contact a soldier is exposed to at once, the more training it takes to remain functional. In any form of battlefield scenario a pre-modern levy army of a city state is going to be overwhelmed very quickly, when men start dropping from what might as well to them be magic weapons (because the people are hit and down before you hear the report of the gun and they're operating beyond the conceivable range of any weapon they are familiar with) and odd whistling sounds followed by sudden explosions keep going off with no warning, they are not going to be able to function. And that's without the iron war-beasts belching more explosions and shredding men with terrible roaring weapons. Any troops a city tries to field are very quickly going to be at best lying on the ground not moving and hoping it all goes away (a very common response to being overwhelmed in combat, the other is rote performance of an ingrained task, in some musket era battlefields weapons were found with 3 or 4 balls loaded, showing that the soldier had probably been overwhelmed and just kept doing the reloading they were drilled to and not actually managing to fire)

This is going to be an outside context problem for the pre-modern city state, the nine hells themselves might as well have opened on top of them. Worse, because at least they have fireside tales of paladins who stand up to those monsters.

Which brings us to the problem inherent in the question, which is: is the Big Red One playing by D&D 3.5 mechanics, or is Faerun playing by real-world Earth physics?

The only even-handed way to do any vs. scenario is to assume that everyone's equipment works as it does in their own setting.

[Divayth Fyr]

The only even-handed way to do any vs. scenario is to assume that everyone's equipment works as it does in their own setting.

This still leaves things like "how does Protection from Arrows work in regards to bullets" or "can the modern force even scratch an incorporeal creature" open to debate.

[dancrilis]

Depends on the edition. D20 Modern is not reality (a gun can easily kill an Elephant in a single shot, a D20 gun will not reliably kill a single person), so I wouldn't use it as a basis of comparison.

There is a big difference between a hunting rifle, and a .50 calibur bullet. The .50 will pretty much amputate limbs if it hits you. Which I'd say is a lot more than just 2d12 damage.

The main difference is that in D20 Modern, the Massive Damage threshold is the creature's Con score, as opposed to 50 in D&D. That means that even most skilled warriors are at risk from most attacks. This leads to more realistic, anti-D&D behavior such as preferring to avoid combat.

I don't really think it is about the gun or the damage so much as the fact that modern humans are effectively very low hp creatures - if an average strenght person gets the drop on a non-helpless modern solider and critical hits them with a knife that solider is out of the fight (almost certainly), on the other hand a level 1 fighter is still standing and effectively fully functional.

Guns in real life are deadly because people (and other creatures) in real life are flimsy (compared to DnD standards) - I don't see any reason to assume that if modern humans attack a fantasy kingdom that there weapons would become more powerful or they would get more hitpoints.

For instance to take The OOTS, panel 12 has Elan impaled and panel 1 has him up active and talking with little problem - that is fine for DnD rules (even if some people like to pretend that hit points are glancing hits and stamina etc).

Now if the soliders invade a more narrative and less rules based Faerun it might balance things out a bit to need the Faerun side to have more high level people - but even if they enter a narrative Faerun that means that the gods are likely even more active, and the soldiers might still get seriously messed up by any underground attacks, creatures or people with invisibility etc, it would just mean that the Faerun side needs to actually consider some basic tactics.

[Kitten Champion]

I think you're underestimating the range (and lethality) difference.

Magic Missile has a 120' range. The effective range of a designated marksman rifle (one per squad, usually) is 250-300 yards. That's about ten times the effective range. Note, that's not a sniper, those are very different beasts (and will be used against wizards).

But that's not realistically the range of combat, at least according to those participating in modern wars

In interviews with US Marine rifleman during the Iraq conflict --

Almost all interviewed stated all firefight engagements conducted with small arms (5.56mm guns) occurred in the twenty to thirty (20-30) meter range. Shots over 100m were rare. The maximum range was less than 300m. Of those interviewed, most sniper shots were taken at distances well under 300m, only one greater than 300m (608m during the day). After talking to the leadership from various sniper platoons and individuals, there was not enough confidence in the optical gear (Simrad or AN/PVS-10) to take a night shot under the given conditions at ranges over 300m. Most Marines agreed they would “push” a max range of 200m only.

Which isn't fundamentally different than WW1 apparently.

The main reason? You need to be within a certain visual range to identify threats. Especially in an urban environment that don't give you extensive sight-lines for kilometers.