My answer is generally “no”, but it depends. An adventure that requires PCs to take certain actions but doesn’t make them discoverable is a crappy adventure. In this case, I would apply the three clue rule to make sure the PCs had a chance of finding out what they needed to know.The constraints of the adventure make it very hard to telegraph information. Like all of the adventure locations are in the middle of nowhere, no one has been there before. For example, no one knew that an evil caster was behind the trouble in the village, let alone to know "you have to use a knock spell" to get into her safe room.
Sending visions or other psychic phenomena just seems too heavy-handed.
That's true, but there are clear degrees here.Overcoming the obstacle is part of the adventure. Figure out what key is necessary for the door then go get that key.
Pretty standard for d&d, I think.
If werewolves could (hypothetically) only be damaged by silver weapons, and the players did not have any silver weapons in a confrontation with werewolves, what would we reasonably expect them to do? Go get some.
Pretty standard for the fantasy genre, too. In the Hobbit, there’s writing that can only be read under the light of the moon (and sometimes only during a specific phase of the moon), doors whose key holes are only accessible at certain dates, and a dragon who has exactly ONE vulnerable spot. Figure it out and do the thing.
It's definitely the kind of thing you'd encounter in adventure/puzzle games ranging from the old text adventure games like the Zork series or Adventure to the graphical oriented ones like Indiana Jones and the Fate of Atlantis. Encounter areas may be treated as puzzles that need a bit of thinking and, in many cases, further investigation and adventuring to find what is needed before they can be solved. Some players really dig that.That's true, but there are clear degrees here.
For example, the PCs need a magic key for the sole door to the next level.
The key is at the bottom of a pool in a remote corner of the dungeon and is only accessible if 1) a PC decides to dive into and search the pool and then 2) rolls a 25 investigation check (why 25, because that's what the adventure designer thought was "appropriate").
The above is way too much gatekeeping for my tastes - but it's not unheard of in published (or homebrew) stuff.
It's definitely the kind of thing you'd encounter in adventure/puzzle games ranging from the old text adventure games like the Zork series or Adventure to the graphical oriented ones like Indiana Jones and the Fate of Atlantis. Encounter areas may be treated as puzzles that need a bit of thinking and, in many cases, further investigation and adventuring to find what is needed before they can be solved. Some players really dig that.
Others are more into the World of Warcraft/Diablo types of quests where the challenge may involve fighting or finding something but the solution is relatively straight-forward and not puzzle-like.
Neither is right or wrong. Either may require you to adjust because of the nature of your players and what they like to play.