D&D 5E Applying advantage to passive Perception

[Li Shenron]

Just out of curiosity, you apply the same categories for all 3 senses ? Even animals with a great sense of smell can't match the range on visuals especially in daylight, I think, wheras it completely inverts in darkness (although shining a light outside at night can get you seen miles away, etc.). This is why I think 5e was right to just let it drop and let the DM rule based on exact circumstances.

You bring up an interesting question...

Without enough knowledge on biology, I have never understood how do shark smell blood at great distances, but they do, and very likely at much longer range than vision, which is impaired underwater.

I wouldn't want to go down the rabbit hole of realism/simulationism so I'd rather adjudicate something on the spot than shoehorning myself into a house rule, and then cross my finger that I don't get a Biology PhD among my players.

 

[Lyxen]

You bring up an interesting question...

Without enough knowledge on biology, I have never understood how do shark smell blood at great distances, but they do, and very likely at much longer range than vision, which is impaired underwater.

I wouldn't want to go down the rabbit hole of realism/simulationism so I'd rather adjudicate something on the spot than shoehorning myself into a house rule, and then cross my finger that I don't get a Biology PhD among my players.

There is an interesting site here: "Under optimum conditions sharks can smell blood from a quarter of a mile away, but it takes time for the smell to travel to them. However, that distance depends on the species of the shark (some can smell much better than others), and on the direction and speed of the water. So, while it’s still a pretty good distance, it’s probably much less than we expected."

And from the amount of diving I've made, I've certainly never seen a quarter mile away, even in the best conditions. That being said, my vision goes in all directions, whereas smell is born mostly along one direction, that of the current.

Again, all more reason to listen to the players and weave the narrative along the lines of "we approach the sahuagin's lairs from down stream, etc." and make your local rulings from that information.