Making knowledge checks useful...

Getting information about an enemy with the appropriate check, in theme with your character:

• A fighter that encounters a wolf should ask for a knowledge check (DM's discretion but Nature makes sense here) and should ask questions like...
  • Have I ran into one of these creatures before? Would I know something appropriate for my character, like the AC, STR saving throw, Athletic/Acrobatics skill, resistances/immunities, (stretch for) perception?, total hit points?
    • Since a fighter may want to grapple, knowing Athletics and Acrobatics skill is useful...
    • AC matters for all martial characters, sharing that information is even better
  • In this particular case, I wouldn't necessarily give the fighter information about a wolf's INT or WIS because it's not information a fighter would normally care about. If it was in theme for the character (or especially the subclass... looking at you, Knowledge Cleric), they should be given more flexibility in what they want to know

Regardless, don't tell them everything about the creature... just one or two pieces of information is enough. If the enemy is rare/unique, don't allow the check; if it's not appropriate for the character to know, don't allow the check.

As someone who DMs a lot of games, when I play and ask the DM for knowledge checks... I'm asking to know what information I'm allowed to use as a character. I'm actively trying to not metagame here. One recent example of this was the DM put "Basilisk" on the initative tracker. As a player, I can infer some things about a basilisk (like not looking at it) but I didn't know if my character knew that.. so I asked the DM "Does [my character] know anything about basilisks? Can I make some sort of check for this?" He said "Sure, make a Nature check." I rolled an 8 or something close to that, and the DM told me "You haven't seen a basilisk before." "Okay, great." Next turn rolls around, the DM asks if my character is looking at the basilisk and I respond with "I wouldn't know to look away, so I'm looking directly at this creature. What's going to happen?" For what it's worth, the two other players at the table (both experienced) immediately ran behind the creature without asking any questions (it was a barbarian and a monk, so I feel like you could rationalize they wouldn't want to stand in front of a creature... but there's also a tail problem).

https://arcaneeye.com/players/skill-checks-guide-dnd-5e/ https://www.reddit.com/r/DnD/comments/2igb02/5e_knowledgeintelligence_checks/ https://www.enworld.org/threads/how-to-handle-monster-knowledge-checks.442598/