wait... like sword damage is force? or they get an eldritch blast like ability instead of a sword attack? or they get an extra attack added on?
Ooooh boy: Stay awhile and listen.
So originally, before Monsters of the Multiverse, there were a number of Monsters/Stat Blocks where they had the trait called
Magic Weapon. The idea is, according to the trait, was that the attacks/weapon used by the monster, were magical in nature. This would allow things, such as Demogorgon for example, to not have to worry about silly things like not being able to damage, say, ANOTHER Demon Lord, like Baphomet or Zuggtmoy if they were all like put in one big Royal Rumble showdown, like in Out of The Abyss. (I've heard/read some posters on here insisting that was a legit thing simply because Demon Lord attacks did S/B/P damage.) So, because Demogorgon had the trait
Magic Weapon in his stat block, when he punched somebody like Orcus/another Demon Lord, they would feel the full force of his blow and not have to worry about Orcus having damage immunity because Demogorgon's attacks, like his fist, are considered
Magical.
But let's say suppose, one day, Demogorgon meets a Barbarian. A barbarian named, mmm, let's call him Gorg, who is a member of an adventuring company called the
Vocal Machine. Now Gorg doesn't like demons very much and Demogorgon is having that moment where he doesn't like any Barbarian he sees. So he straight up punches Gorg, who has already entered into Rage by then. Now unlike Orcus, when Demogorgon punches Gorg, his magical demon fist does Bludgeon damage. It's magical Bludgeon damage, but still Bludgeon damage nonetheless. So Gorg just smiles with a bloody lip, proceeds to spit the blood back in his demonic opponents face, and only suffers half damage because Barbarians, when Raging, have Resistance to Slashing/Piercing/Bludgeoning damage.
Now, the
ONLY damage type in 5E, that doesn't have to worry about getting blocked/resisted, most of the time out side of DM fiat/rare things, is
Force Damage. Which is explained in 5E as being pure, raw, arcane/magic power. Lets circle back round to our buddy Demogorgon. He, post Monsters of the Multiverse, has been "updated/buffed" because of the trait
Magical Weapon being removed from stat blocks. Instead, to emphasize the fact that Demogorgon's demon fist/attacks are magical, they were changed from doing
Bludgeoning Damage to Force Damage. Meaning that poor ol Gorg the Barbarian can not only feel the full blunt of Demogorgon's wrath, but also the look of horror on his player's face when the Prince of Demons just straight up murders Gorg on the spot.
It's no laser beam or anything, unless the attack is made as that. Orcus, devils, demons, Demogorgon, and a buncha others were updated to do Force Damage with their attacks. Any reprints of prior stat blocks that had the trait
Magic Weapon will probably be retroactively updated to now do Force Damage. So unless your a Shadar-Kai or something that has Necrotic Resistance, your going to be feeling
ALL of Orcus's attacks when he's swinging his Wand around.