Observant Feat

Well, there's a few ways to go about this. Let's start with this tweet from Jeremy Crawford, the one we all go to for Sage Advice:

(Pulled from

Investigation is pretty much the same way, only doubly so. You can't investigate something you haven't seen yet. So, if it's something hidden, your Investigation skill won't help you any; you'll have to Perception perceive it first. Or have someone else point it out to you.

Next, Crawford also has this advice on passive investigation:

(Pulled from

And the PHB has this to say about the investigation skill itself:

And in the 27 Apr 2017 episode of Dragon Talk, in Sage Advice, Crawford describes passive perception as follows:

(27 Apr 2017 Dragon Talk: dnd.wizards.com/articles/features/james-haeck-dd-writing)

(Excerpted quote pulled from www.dndbeyond.com/forums/dungeons-dragons-discussion/rules-game-mechanics/2793-stealth-advice-from-jeremy-crawford on 25 Apr 2019)

So, what should we take away from all this? Your passive investigation score may give you clues for free, without you, as the player, having to roll the die to see if you piece them together, if the DC for the investigation check is equal to or lower than your passive investigation. However, from the DM's side, this doesn't mean they are compelled to give you any and all clues that are available to you without you having to roll a check. It's a tool for the DM to use if they want to.

But that's just a meaning. My advice to your DM is to make use of your character in the same way that you might use NPCs: on occasion, your character has some bit of information that is necessary for the party to proceed, or to proceed more effectively. Especially when the players are having a rough time figuring something out. Players have been spending the last hour trying to piece together this puzzle? Your character gives them a hint. ("I think we should start by rotating the wheel to the left. That seems to have done something each time we've tried.") Your party is trying to get to the bottom of a murder mystery? Your character understands something the players don't. ("Y'know, if the lord's nephew was killed in the garderobe, if something was dropped down the chute during the murder, it might have washed downstream. Maybe we should check there.")

Making use of the Observant feat in this way does a couple of things for the table: first, it makes the PCs more important. They are the ones figuring things out, not the random NPCs giving them information. Second, it makes the player feel like they didn't make a bad choice with that feat. If a feature never has the opportunity to be used in an adventure (like having a ranger with a favored terrain of "arctic" when you're playing Waterdeep: Dragon Heist), it feels like a bad choice. Without making good use of the passive boost to both perception and investigation, all you get is the ability to read lips and a +1 to intelligence. Might as well just do a +1 to int and a +1 to some other ability score.

Ultimately, though, you already said the right answer: "in the end, its his call to adjudicate this ability." As Crawford said of passive perception, your passive investigation "is an option that a DM chooses to use or not." While I may think it's a bad call to not make use of it on occasion, as long as the game is still fun, that's what matters.