Fundamentally, it is going to be a matter of perception more than actual power. My players have certainly noticed the spell, and find it 'cheap' -- they tend not to use it and dislike it being used against them. It is the
Force Cage of low-level spells (or maybe a
Sleep spell, but without the steep drop off in effectiveness after the first level or two of play) . I think it is a symmetry-seeking part of the brain that objects to it more than anything.
Fireballs have a regular defense -- the Dex save.
Eldritch Blast has a defense, it is AC.
Hypnotic Pattern has a defense, it is a Wis save, your friends taking an action to awaken you, the enemies doing damage to you,
Dispel Magic, or the party engaging the caster and dropping them to 0/forcing them to fail a concentration save.
Heat Metal has a defense: the last two option
Hypnotic Pattern has, or not having been wearing metal armor in the first place. It seems like it is breaking an established pattern by not having another check/constraint/counter for a (potentially lethal or crippling) ongoing effect.
My NPC usually get this spell cast on them.
Most humanoids and some undead wear metallic armor. Meaning easy damage. Cast on a non armored foes, the spell will effectively disarm foes. A fire giant might not mind the spell, but a frost giant will hate it.
Hobgoblins from the get go have chain mails.
Even a gladiator will be vulnerable as studded leather has... studs. Metallic ones at that.
The spell specifies medium or heavy metal armor, so studded leather is safe. I will point out one quirk, though -- No where in the description of studded leather ("Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.") does it mention metal. Rivets would be hard to imagine as non-metal, but spikes certainly could be (especially if maybe this was crafted in Chult or something, where the spikes might come off a dinosaur or giant armadillo or something). Ring mail has the same issue, although I'd find myself significantly less persuaded that someone arguing this was doing so in good faith.
As for the "running away" strategy, the issue that's massively sub-optimal, tactically. You're abandoning all your buddies to get killed, in the hopes that maybe you do enough damage to kill a PC. If you stuck around, you could still do damage, still cause a distraction, and so on. Your side's overall performance would be much, much higher. It's essentially a 1:1 sacrifice at best.
Agreed. It is middling at best unless you do some schlocky exploit like ducking into an un-reachable hole or other DM-placed impunity-spot, don't care that your buddies (should you have any) are getting trounced, and basically exist as a way to gank a single opponent.
One response would be 'so it isn't really a problem,' and I generally agree. Excepting that the problems is that a less gimmicky version of this spell (with broader applicability but not this gimmicky option souring people to the thing) could be in the game instead of this.
There's also other issues I have with it. If you're wearing metal armor you are not in direct contact with it, you are wearing a gambeson underneath. It's also not like armor is one solid chunk of metal.
Logic would certainly suggest that -- I guess sometime chain shirts were worn with just normal clothes underneath (because 'I can have this on at a moment's notice' was a primary value of the thing), but in general armor would have had arming jackets underneath. I guess it could be argued that, since it isn't a separate item on the equipment list, that the gambeson is part of the metal armor, and thus the creature is in contact with it. That's where sensible DMing helps, but then the devs probably could have specified that in the spell description as well (and I think it doing 2d8/rnd to the person who won't let go of their hot weapon but only 1d8/rnd or something to the person who can't drop their plate but are protected by their padding would make the spell more interesting in terms of choosing your target).
That's some nice rule of cool. I always hated the rules for donning/doffing armor, realistic or no. Especially with all the times you find yourself treading water unexpectedly in D&D.
There's a lot of ways that the game can be realistic that just reinforce that no one in their right mind would actually do what PCs regularly do. If dank holes in the ground full of monsters, treasure, and environmental hazards like sudden deep water existed, people would have developed armor specific to that situation (but kinda like the weapons which would have been developed if Giants and Dragon Turtles existed, is it ones' power fantasy to play with those?).
However, this was not something we'd see in combat. This was a well executed use of the spell as an assassination technique. In combat, that druid either would have been out of the fight (and as they could cast 5th level spells, tthey'd have been a significant percentage of the firepower in the battle), or they'd have been targets for breaking concentration.
I think that's my main dislike for this -- it isn't great when used in combat, but it can be devastating in a targeted assassination plan, and I don't need a lot of page space (much less an iconic spell) dedicated to a niche like that.
