You did get that I originally said "in a setting where they are rare" right? Settings can make them common, uncommon, rare, very rare, unique or gone entirely.
And if they are rare... they are still potentially a playable race. They would still be, for OD&D, in the player's handbook.
And still, they are just people. Normal humanoids. Why would I go into battle with an orc and assume they are resistant to acid damage? They are just people.
Goblins are only a playable race if the DM allows it, and are only common in settings where the DM determines that they are common. This includes official settings like the Forgotten Realms where the DM has changed goblins to be rare.
And still doesn't explain why I must assume they are resistant to fire. Why can't I assume they have no vulnerabilities? Why is assuming the baseline metagaming? Just because you don't like it?
Winter Wolves who are immune to cold exist, so why not a fire version?
Then, just like Winter Wolves aren't Wolves (they are two different things) these would be Fire Wolves. And, yeah, I'd assume wolves with embers falling from their fur and breathing fire are immune to fire. Why is this a bad thing?
Owlbears were created by magic. Who knows what magic might have done to them?
It could have... combined an owl and a bear, neither of which are resistant to fire. Are you saying that I should be forced to roll some sort of arcana check before I cast a fire spell, because my character would of course choose to use their action trying to figure out if a normal looking animal (because while they are monstrisities created by magic, they are also common forest dwellers) is immune to fire first?
Again, why is my assumption of null a problem? Why is it so hard to believe that DMs how constantly claim they foreshadow traps will foreshadow things like monsters being immune to fire.
It is entirely about what your characters know.
Well, my character knows that smashing a fluid with a mace isn't effective, so they can figure out that smashing a magmin with a mace isn't effective. Entirely in-character.
That's false. It isn't about different logic and is entirely about what their characters know.
And every time I've presented what the characters know, you swoop in and say "But what if they are wrong? What if it isn't that? What if magma can be SCOOPED!"
This isn't about what my character's can justify, this is you harping on about how I'm a terrible metagamer, because I don't waste time wondering if creatures made of flame are immune to fire.
There's no reason to think that animated armor would be resistant to weapons. PCs wearing armor do not gain resistance when enemies hit their armor, so why would walking armor be any different. Undead created through negative energy(necrotic) are opposite to positive energy(radiant). That was a shifted goal post.
So... poison not working on animated armor is a goal shift because weapons will? Well, someone is certainly shifting goal posts to go from discussing poison to discussing weapons. Also, animated armor ISN'T resistant to weapons, FYI.
And undead being created from negative energy which is opposed to radiant energy... also has nothing to do with poison. Second goalpost shifted. Are you trying to make a triangle?
No. It's a good thing for me that's a false equivalence. Demons have a variety of resistances and immunities. They are not all resistant to exactly the same things. Same with devils. Not sure about elementals, but after the first two I'm not going to look and see.
The ability proposed would continue to be useful against demons, devils, etc.
Hey, it's the triangle!
Because, no, they don't. See, now I'm going to ACTUALLY meta-game and read the Demon statblocks. Tell me if you notice something
Balor: Resistant - cold, lightning, nonmagical weapon damage. Immune - fire, poison
Barlgure: Resistant - Cold, fire, lighting. Immune - Poison
Chasme - Resistant - Cold, Fire, Lightning. Immune - Poison
Dretch - Resistant - Cold, Fire, Lightning Immune - Poison
Glabrezu - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Goristro - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Hezrou - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Mane - Resistant - Cold, Fire, Lightning. Immune - Poison
Marilith - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Nalfeshnee - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Quasit - Resistant - Cold, Fire, Lightning. Immune - Poison
Shadow Demon - Resistant - Acid, Fire, Necrotic, Thunder, nonmagical weapon damage. Immune - Poison, Cold, Lightning. Vulnerable - Radiant
Vrock - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Yochlol - Resistant - Cold, Fire, Lightning, nonmagical weapon damage. Immune - Poison
Now, I'm sure you've noticed how these are... basically identical? The only difference is whether or not they are strong enough to be resistant to mundane weapons. And, I know, you are about to pee yourself with excitement, because fool that I am, how could I not notice the Shadow Demon? Doesn't that disprove my entire point, this single monster?
Actually no. Because Shadow demons are incorporeal. And incorporeal foes share a lot of those same exact traits. So, you just need to know that it is an incorporeal demon... which is kind of in the description? So, after the first time you fight a Mane or a Dretch, you basically know all the resistance and immunities of every demon.
So, once you have used your Hunter's Lore, or Lore Bard's Lore on the dretch, what do you gain by using it on the Glabrezu? Literally only that the more powerful demon is resistant to nonmagical weapons, which is only useful if you HAVE magical weapons that are worse than your non-magical weapons. Otherwise, it is useless information.
So, no, it isn't a false equivalence. Once you learn what one demon's R's, V's and I's are, you basically know all of them. Because they are standardized.
How do you know he cast no spell? Not all spells use components. And I can flavor my wizard PC to have his eyes blaze with lightning when I cast electrical spells.
Every spell uses at least one components. Verbal is the most common, and I can't think of a single evocation spell that doesn't use it. And you are sure welcome to have your wizard do that, but since your wizard isn't a giant with an elemental theme, it probably won't lead to the same conclusion. You can't just scream "but he might be a wizard!" and expect me to ignore what giant's are, and how they work, ESPECIALLY when you brought up frost giants in comparison. So, I've encountered elementally themed giants once before. Why would I suddenly act like I have no idea what I'm seeing here? Why do you insist my character must be too stupid to use basic logic?
That's an objectively false statement. Alignment is not the only difference between those planes.
For someone who isn't metagaming? There is no other difference.
So you assume that the creature is immune to fire and use lightning, which is what it really is immune to. You've wasted a spell, done no damage for the round, and could end up dead because of it. In a tough fight one round of doing no damage could mean all the difference.
Assumption can bite you in the rear. Not will. Can.
Well, if I ever encounter a creature made of fire that is actually not resistant or immune to fire, but immune to lightning, I'll be sure to send you a PM and tell you how right you are.
However, in the world where DMs aren't purposefully making gotcha monsters to punish players who use logic, that is never going to happen.
I'm not sure why it's so important for you to make a troll's vulnerability to fire and acid not a vulnerability. It's not the same kind of vulnerability as taking extra damage, but when you can come back from anything, including death unless fire or acid are used, those are vulnerabilities.
Because it isn't a vulnerability. Vulnerabilities are called "Vulnerabilities". The troll ability is under "special abilities" and called "regeneration"
You want to talk about things that bite you in the rear? Writing rules and assuming people won't follow the RAW. That WILL bite you in the rear, consistently, because DMs are far more likely to follow RAW than whatever psychic signal you were trying to send them. Right the rules for the ability you want, if you want them to know a monster's special abilities, put it in the rules. Don't just assume it is obvious and of course everyone will agree with you.
Because half damage can still be effective. I was talking about assuming immunity. You don't know whether something that uses cold and/or lives in the cold is immune or not. Resistance is just as likely an option.
Uh huh. So, if I have a choice between dealing half damage, and dealing full damage by not gambling on that... why in the world would I choose the half damage? Also, what you were talking about seems to not be what I was talking about. You have this bad habit of shifting the goalposts mid-stream without telling anyone you are doing it.
So you walk into a bar and ask the paladin what his armor class is? No. You don't, because while armor and being harder to hit/damage are things in the fiction, armor class numbers are not. Hit point numbers are also not a thing in the fiction.
Why in the world would I ask? If he is wearing full plate is armor is 18. That information is right there in the PHB. It isn't metagaming to know what AC's armors give. If it were, then when the player is trying to buy better armor, the DM would just not tell them what the armor does and make them guess. Maybe they would even hide their AC from the player.
But that doesn't happen. Because AC is not a metagame construct. It is something the player is fully allowed to know, in world.