D&D 5e Speaking of CR vs. Magic Weapon (giving out too many, hmmm?)

 https://www.reddit.com/r/dndnext/comments/nepiwa/how_in_the_hells_are_you_supposed_to_fight_a/

Quoting BmpBlast, yeah I kinda agree:

Yeah, if you examine the math behind the game it's pretty clear the game is balanced around NOT having any magic items. Expected to-hit values for PCs stay pretty evenly at 60-65% across the entire CR range when fighting monsters of "appropriate" CRs and there are no +X magic items. Same goes for average rounds-to-kill when examining PC damage and comparing with monster hit points. So basically the more magic items a DM gives their party, the more they need to ramp up encounter difficulty to keep the true encounter difficulty the same.   

Problem is definitely so many monsters are immune to non-magic. But maybe Silvered weapons is the answer. Somebody just said that the new 2025 Monster Manual removes a ton of "immune to nonmagic physical attacks", which is funny, b/c I was all about finding monsters that are essentially immunte to EVEN magic weapon dmg. I mean, magic weapon dmg shouldn't be the super ulimate beats everything, that's boring. I'ma gonna homebrew. 

But there are these things that I discovered, thanks DragnaCarta:

Six swarms of bats, in a room of fog, is very very hard to hit/dmg even with magic weapons. 

• Swarming tiny things go into your square, so friends dare not attack
• Swarming tiny things take like half damage from all physical (pierce, slash, bludg) b/c they are basically calculating for a tiny army's avg HP and avg attack power
• half hp the swarms do half dmg
• super fog makes it so everybody is blind
• bats can see in blindy rooms with sonar

So if the Rakshasa has always been, and the Tarrasque-2025 are both anti-magic user bosses... what are bosses that are anti-melee/anti-bow, where the Mage has to DPS to save the day? If there isn't one, I'm damn well making one. 5e just feels like melee centric to me. 

• Let's think. Beholder? Doubt it.
• Demons/devils? Doubt it. 
• Vamps? Well now with legendary resistances, I doubt it. 
• Flying things kinda sorta? Gotta be something, I need to research. 
• https://www.reddit.com/r/dndnext/comments/zcgype/monsters_with_resistanceimmunity_against_and/
• NOBODY WAS HELPFUL IN THIS THREAD
• Did any of you tried this concept before? I once did a magic statue which was resistant against magical weapons, but had vulnerability against adamantite.   
• https://www.reddit.com/r/dndnext/comments/pfqdm5/are_there_any_monster_resistant_to_all/
• Hopefully this is better thant the first one.
• LAVA CHILD - yep
• creatures which, apart from looking like total nightmare fuel, are entirely immune to bludgeoning, slashing and piercing by any metal weapon, magic or not. They also attack with advantage if their target wears metal armor, and can pass through metal as if it isn't even there. They also cause automatic damage upon touching or being attacked in melee.   
• Here's a D&D Beyond filter of monsters. Though a vast majority of it are Swarms lol.   
• Cadaver collector only resists B/P/S from Non-magical weapons that aren't adamantine, any +1 or higher weapon, or something like a Flametongue/Frostbrand weapon would still hurt as normal   
• Sort of, there is a few that are close.
• The Sorrowsworn(The Wretched, The Lost, The Lonely, The Hungry, The Angry) from Mordenkainen's Tome of Foes are resistant when in dim light or darkness(perfect for parties that all rely on darkvision).
•     Demilich(Monster Manual) is resistant to b/p/s from magical weapons, immune to b/p/s from nonmagical weapons, but not b/p/s in general. And as I just found out, it lacks the (hover) trait, so you could grapple it for fall damage.(possibly an error on Roll20)
• Most Swarms(probably all of them, but I dont have every book) are resistant to b/p/s
• Treant(Basic Rules) and Wood Woad(Volo's Guide to Monsters) are resistant to bludgeoning and piercing, but not slashing, seem to be the only monsters resistant to 2 out of 3.
• Dndbeyond shows a "Priest of Osybus (Spectral)" from Van Richten's Guide to Ravenloft under the filter Resistance: All damage but force, radiant and psychic, But I dont own that, so Im not sure if there are any other qualifiers to that.   
• OTHER DUDE
• let's tab to left again... 
• <---

     Humanoid Barbarian using Rage (just slap it on any humanoid creature from MM/Volo). Your players are going against any Church/God? Raging zealots (not a barbarian archetype), maybe even army of raging commoners. Underdark? Berserks on mushrooms. Nine Hells? Raging devils of rage. Abyss? Demons are just angry all the time.

From MM/Volo I personally dont remember anyone resistant against flat piercing/slashing damage, sorry.   

AND

     MM:

Awakened Shrub (only flat piercing)
Awakened Tree (bludgeoning, piercing)
Flameskull (piercing)
Swarm of Bats/Beetles/Centipedes/Insects/Poisonous Snakes/Rats/Ravens/Spiders/Wasps
Treant

Volo:

Swarm of Cranium Rats/Rot Grubs
Thorny
Vegepygmy and Chief (piercing)
Wood Woad

There could be more setting specific, but generally thats all   

Funny thing, Demiliches resist B/P/S only from magical weapons specifically, technically they can still take B/P/S damage from the following spells;

Arcane/Bigby's Hand

Black Tentacles

Blade Barrier

Catapult

Cloud of Daggers

Control Water (Whirlpool option)

Cordon of Arrows

Dust Devil

Earth Tremor

Earthquake

Ensnaring Strike

Erupting Earth

Hail of Thorns

Ice Knife

Insect Plague

Investiture of Wind

Maelstrom

Maximilian's Earthen Grasp

Meteor Swarm

Storm Sphere

Thorn Whip

Tidal Wave

Transmute Rock

Tsunami

Wall of Thorns

Whirlwind

Wind Wall

Wrath of Nature (Trees or Rock options)   

 Rakshasa stuff:

     A Rakshasa can be dealt with by:

A high level caster putting holy weapon on a martial piercing weapon

A high level casater putting elemental weapon on a martial piercing weapon

A high level caster putting magic weapon on a martial piercing weapon

A high level Bladesinger with ShadowBlade

A Kensai Monk

A Sun Soul Monk

A couple classless Monks

A Hexblade Warlock

A pact of the blade warlock

A couple paladins smiting

An Arcane Archer

A Soulknife

An Oath of Devotion Paladin

A Forge Cleric making a martial's weapon magical

An Artificer making a magic weapon

If a party has none of those then yeah they're SoL but that is a lot of options. The only classes not there are Barbarians and Rangers, every other class has the ability to deal with it or allow someone else to deal with it.