Metagaming

>The lumbering giant roars and reattaches his arm to his shoulder, it growing back almost instantly. With eyes full of hatred he-
>Oh, it's a troll, we must hit him with fire!

How the fuck do you stop players from using out-of-game knowledge in-game? I tried not telling them monster names, they still deduce them. I tried making monsters look different, they guess it by abilities they use.

Should i just make trolls HEALED by fire damage?

yes

i'm not even kidding, if this is a legitimate problem in your groups, do this. destroy everything they thought they knew about fantasy settings and make your own shit up

>use cliches
>get mad when players recognise and exploit them

>ha the players will never know how to beat the tree-demon
>fuck they set it on fire, meta-gaming shits

This on every level.

Oh hey, it's this thread again.

this wouldn't happen if you were less shit at your job as dm op

>Metagaming thread
>Fucking trolls
Every single time. Isn't there a single other example you could use?

How about you make a troll with a fire protection amulet he stole from some mage which absorbs sources of flame?

come on OP, step it up.

Oh, that's a good idea.

Look, i wouldn't have been miffed as much if they even made a lore check.

But noooo, every character is an instant monster expert.