View Full Version : How to track an invisible creature?!?!?!

07-22-2010, 05:54 PM
Okay, I'm a GM working on a scenario for my group (who will be about level 12 or so when I run this particular scenario). I would like them to be able to follow an imp (which can turn invisible and fly) back to the villains lair. But, in 4E there doesn't seem to be a way to detect invisibiltiy. I think I saw a True Seeing ritual somewhere but I think it was fairly high level. Even the Detect Object ritual only lasts 5 minutes (the imp is carrying something, or course).

Anyone have any suggestions/ideas to help my poor players?

07-22-2010, 06:47 PM
Detect Magic, Arcana skill trapping: use as mystical Perception, or for tracking the imp once discovered. If you want, turn the chase into a skill challenge; failure could mean boosted defenses, or the party walking into a trap. (Handwave the range limits if it becomes an issue.)

If you don't want to get mechanically involved, write off the invis as temporary, or provide a means of (semi-)permanently neutralizing the power (McGuffin of imp detection, or very specific "ritual"), or give tells of an invisible creature (like leaf rustling, obvious noises, etc.) that can be tracked as normal. Unless you have another means of the PCs finding the evil lair, don't keep the imp 'invisible' longer than necessary, regardless of method. Provide the players with the information to act, and let them act.

07-22-2010, 08:33 PM
I would echo the suggestions Sascha made. I'd probably avoid setting a precedent for using specific rules to track invisible creatures; this solution just begs to come back and bite you when a similar situation arises in the future. I like the idea that the players can track the imp by the subtle signs he leaves behind, like rustling leaves or placards which spontaneously start swinging, etc. Perhaps the imp simply isn't being all that careful because he doesn't know he is being followed. The challenge becomes reversed. The party uses a combination of stealth, bluff and perception to avoid being detected by the imp and to follow in the imp's wake of mischievousness -- as the imp occasionally stops and plays a prank on some hapless soul along the way.

07-22-2010, 10:09 PM
Detecting creatures is Perception vs. Stealth. The reason there are no rules for detecting invisibility is because there are also no rules that say, in essence, "Invisibility prevents detection of creatures by Perception vs. Stealth." If this sounds weird or counter-intuitive, let me put it another way: if there was some careless invisible person in my house, who was just hanging out and doing stuff, I expect I'd notice in a matter of seconds. From a mechanical point of view, there are plenty of situations where a character isn't allowed to use Stealth to become hidden. Invisibility provides, in the first place, a sufficient condition to allow a character to make Stealth checks and become hidden.

So, putting this into action, if the imp was visible, and was flying back to its lair, chasing after it would be as easy as running after a balloon. The fact that the imp is invisible lets it make Stealth checks when it otherwise wouldn't be allowed to. Furthermore, the imp is going to be taking penalties to those Stealth checks based on its movement: -5 if it moves more than 10' per move action; -10 if it's running. The party gets to make Perception checks to beat those Stealth checks and follow the imp. Considering the party's twelfth level with a base Perception of +6, and the typical imp has +9 Stealth, this shouldn't be difficult at all.

None of this is in opposition to the suggestions posted above. Sascha's idea of a skill challenge seems perfect for the sort of situation you seem to be intending. I'd also pay special attention to her penultimate sentence which I take to mean: does the party have to find the lair, or are there other options available if they fail?

Also, I particularly like Farcaster's idea for the nature of the skill challenge: it's not about the party being able to follow the imp; it's about them being able to follow it undetected. Also, his various ideas about the disturbances the imp causes on its trip back to its master are precisely the sort of details that a successful Perception vs. Stealth check would reveal.

I'd like to make a few tangential comments, too. Following an invisible creature, all other things being the same, isn't as much of a problem as tracking a flying creature after it's already passed through an area. To my thinking, evil, sneaky spell casters employ imps precisely because they don't want nosy adventurers to track their servants back to their lair. The party should appreciate its good fortune in finding themselves in the proper circumstances to be able to do so. This also presents an idea for a possible consequence of failing the skill challenge that Farcaster described: if the imp realizes that it's being followed, rather than lead the party to the villain's lair, it leads the party into an ambush. After the party resolves the ambush, perhaps there's some clue left there that will eventually allow the party to find the lair.

PS: Shouldn't this be in the 4th edition sub-forum?

07-23-2010, 04:05 AM
Thanks a bunch for the ideas/suggestions/help everybody. I haven't had to deal with invisibility much in 4E and I still tend to think of things in regards to how 3.5 did them. Heck, I still ask the party for Spot checks sometimes.

Yea, I suppose this should be in the 4E sub-section. I didn't even notice there was a sub-section to this sub-section until after I had made my post. My bad.


07-24-2010, 06:14 PM
invisibility in 4e works pretty much as in 3.5, in that it provides total concealment. Total concealment allows you to make a stealth check to avoid being detected--but you are not automatically hidden. You simply have the condition of total concealment. Where it digresses is the penalties and advantages associated with total concealment. No more 20%-50% miss, +20 hide, etc. Instead you Gain combat advantage, have a -5 to be hit, and allowed stealth checks to be and remain hidden.

A skill challenge can utilize many skills to allow the tracking of the Imp, including insight to think about where the imp might be headed, arcane to detect any magical trail, nature to notice a trail, etc. The imp could also leave traces of his escape by being wounded and leaving blood, evidence it came across another creature, etc. Many ways you can make this work the way you want. ;)

08-25-2010, 09:52 AM
I've used several mechanical means over the years. Any cloud of dust, like a bag of flour. They will get covered i the dust, or at least u can follow the outline or disturbances in the cloud. They will also leave footprints.Also used a Decanter of Endless Water, in geyser mode. Just had it rain down. Same principle as the dust. the thief in question also left behind wet footprints.

Glitterdust works well too

It might not be enough to accurately fire a bow or magic missle, but it will give the general area to target a fireball or other area effect device or spell.