D&D 5E Finding someone by scent in a city

[Tonguez]

Dogs' sense of smell is hard for us humans to really comprehend. They can detect and discriminate scents that humans can't even notice and ten times the potency. It would be quite easy for a dog to pick out a scent from an item and then follow the person's scent through a city. There are some differences between ground and air-based scent dogs, but the most important factors are:

1. How long has it been since the scent was left?
2. What has the weather been like since then?
3. What kind of item are the dogs using to acquire the scent?
4. What kind of handlers do the dogs have?
5. Are the prey trying to hide their scent tracks?

1. Obviously, if the scent is a week old, it's pretty much impossible (years and years ago, the record for a bloodhound successfully tracking a fugitive by scent was something like 4 or 5 days; that record might have been beaten, but probably not by much at all).

2. If it's been raining continuously for 12 hours, that's probably just as bad as dry weather for 4 or 5 days (and in a city, there can be all kind of things that have effects similar to weather).


As for the Rule of Cool, if the PCs are trying something new and creative, I would give them a reasonable chance of success if the scheme isn't too far-fetched.

Its important to remember that dogs following scent trails are Trailing scents and dander in the air NOT Tracking spoor on the ground.

2. the idea that rain is bad is actually not true, scent particles tend to be hydrophillic and the large particles Dander (skin fragments, sweat and saliva) are attracted to dampness. Rain actually helps to settle dander on the ground and that allows the dog to trail it better.

Dry windy weather is worse as it disperses scent over a greater area and thus means the dog needs to take longer to explore the trail. Thats where a skilled handler who understands how scent works helps, as they make judgement calls of patterns of dispersal and can direct the dogs into shaded areas where they are more likely to pick the trail up again.

Time and wind are the issue, but in a medieval city I think trained dogs with a skilled handler could find a recent trail easily enough.

 

[Bawylie]

Give one dog the urchin background.

 

[Oofta]

How long ago was the trail made? How far? Was the person being tracked distinct in any particular way from normal?

Once you get close to the target, the tracking dog could be useful, but there will be a lot of smells to distract the dog along the way. If you're ever in a situation where people are using dogs to track you is to head to the most crowded/smelliest place you can find such as a supermarket or gas station.

So I'd run it at as a series of skill checks, but the dog can't do all the work. They may be able to help here and there, but I would run it that they lead to an area with one or more clues that leads to another area they can track again for a little bit. Make the dog useful, don't let it be an automatic win.

 

[NotAYakk]

So I asked google "can scent hounds track in a city".

I got this:

In a “concrete jungle” like in the city of downtown Vancouver, summer searches can be difficult after more than a few days. We will generally treat it more as a long lost pet search and strike out looking for fresh scent, as often after 48- 72 hours in a busy, hot, sunny area, a trail on cement is rather tough to follow. In a more residential area, with grass, shrubbery and shaded areas, the scent is protected for a greater length of time, and our hounds are much more likely to catch a trail.

From a "use scent hounds to track your lost pet" website:

| How Does Scent Work?

So there we go; a scent that is 2 to 3 days old is probably going to be too old, but a fresher scent is trackable.

Remember, we turn a noisy jumble of electromagnetic energy bouncing around a room into coherent high resolution pictures that lets you determine properties of materials on the other side of the room, or even 10s of km away (I can see the glint of water or metal in the far distance in the desert; I'm detecting the electron-binding properties of molecules by how they interact with photons sent from a star almost a billion km away, then bounced to two small openings in my skull, focused by flexible organic lenses, hitting chemical photoreceptors, processed by neural networks, then delivered to my consciousness. It is ridiculously implausible). Our ability to see is miraculous, and would be implausible if it wasn't commonplace.

Scent hounds are like that, but with scent.

 

[Arvok]

Its important to remember that dogs following scent trails are Trailing scents and dander in the air NOT Tracking spoor on the ground.

2. the idea that rain is bad is actually not true, scent particles tend to be hydrophillic and the large particles Dander (skin fragments, sweat and saliva) are attracted to dampness. Rain actually helps to settle dander on the ground and that allows the dog to trail it better.

Dry windy weather is worse as it disperses scent over a greater area and thus means the dog needs to take longer to explore the trail. Thats where a skilled handler who understands how scent works helps, as they make judgement calls of patterns of dispersal and can direct the dogs into shaded areas where they are more likely to pick the trail up again.

Time and wind are the issue, but in a medieval city I think trained dogs with a skilled handler could find a recent trail easily enough.

You and I might be thinking of different things when I say a 12 hour rain. If it dumps rain for 12 hours straight (like it does from time to time where I live and we can get 4 or 5 inches in that time), it's a lot different than if there are spotty showers or a light drizzle. Medieval cities were designed, in part, to take advantage of rain to wash away all the filth that accumulated, so a good, hard rain would likely make it harder for the dogs to trail.

I think I'm starting to go down a rabbit hole here, though. We seem to agree that under reasonable conditions hunting dogs should have a fairly good chance of finding their quarry.

 

[Shiroiken]

My group (a 1st level party) is searching for a missing person inside a city. They've got a couple of good hunting dogs and an item that belonged to the person that carries her scent. I'd love to hear how you'd run the search. Specifically:

1. Is it even remotely plausible that dogs could track down someone in a city like this based on their scent?
2. Would the dogs track the path the item's traveled, or would it lead them straight to the person?

The party could certainly ask for help from various NPCs, but it's unlikely they'll be able to find anyone willing to cast 4th+ level spells for them at this point. No one in the party has Speak With Animals, so verbally coordinating the search with the dogs isn't possible.

Since the party has the hunting dogs they should be trained enough to do this, provided less than a few days have passed. No coordination is required, as the hounds will simply do what they're trained to do, which is follow the direction of the scent until it inevitably leads to the mark (or it loses the trail). The downside of doing it in a city is distractions: mixed scents (red herrings), crossed paths (where they've gone multiple times), and other animals (especially during mating season!).

I'd suggest throwing a few encounters along the way that might distract the dog or the characters (check out the chase rules for a few ideas). If you don't want the players to succeed in this way, I'd simply have the dog lose the trail fairly early on, allowing the players time to pursue another option. You could also simply say it works and move on to the next part of the adventure.

 

[GSHamster]

I say you let it work. At the very least have the dogs take the PCs to an area where they can find eyewitnesses to keep them going on the trail.

 

[Guest 6801328]

Rule of Cool > Simulationism

 

[Oofta]

Rule of Cool > Simulationism

IMHO, not if "Rule of Cool" means "bypass all challenges without any risk of failure". In some cases, PCs should be able to play the "I win" card, but if they can always pull that card I think the game loses something.

 

[TaranTheWanderer]

I agree with a few of the comments here:

The party was smart enough to use dogs to solve a problem. That should enable them to do a search in the first place when a search might not have been possible. It might enable them to do a search with some kind of advantage if a search without a dog was possible.

If you want to make it exciting and put in challenges, then do so. Giving one or more of the PCs an opportunity to overcome a challenge would be fun.

If you want the story to progress and want to reward the party for using a creative solution and, possibly, using resources to hire tracking dogs, then segue straight to the location of the person.