How to handle Invis Creature stalking the party

[werk]

Here's the situation. A creature is invisibly walking with the party about 60 feet from their location for over an hour.

Not to avoid the question, but...Invisibility is 1min/lvl. greater invis is 1rd/lvl.

How is he invisibly stalking them for over an hour?

 

[Artoomis]

Not to avoid the question, but...Invisibility is 1min/lvl. greater invis is 1rd/lvl.

How is he invisibly stalking them for over an hour?

A "creature." Lot's of creatures have some sort of supernatural invisibility not bound by spell durations.

 

[Nim]

Not to avoid the question, but...Invisibility is 1min/lvl. greater invis is 1rd/lvl.

How is he invisibly stalking them for over an hour?

A "creature." Lot's of creatures have some sort of supernatural invisibility not bound by spell durations.

For instance, they might be stalked invisibly by...an invisible stalker?

 

[Slobber Monster]

I favor opposed checks each round, because I think that is what the rules include, and also because it seems like a good system. It will make following a group that close for an hour quite improbable, but I think that it IS quite improbable unless the follower is extremely stealthy. The follower cant’s take 10, in my view, while the followed should not want to, so I think the DM should just keep rolling until the stalker is heard, and then proceed from there with the rest of the encounter.
If the timing is not crucial, then I agree that the DM could simply accept that someone’s check will eventually detect the stalker, and just pick a person and time for it to occur.

I agree that stalking someone closely for an extended period of time should be pretty hard without an overwhelming stealth advantage. However, the one problem with rolling every round is that you run into problems with the granularity of the d20 system. For any combination of skills and circumstances, there's going to be a distance at which it's completely impossible to hear the opponent. If the opponent follows 10' closer than this distance, then the listener will hear them on a 20 if the stalker rolls a 1. That's a 0.25% chance per round of detection, which over the course of an hour makes detection (guesstimating here) about 70-80% likely. Over two hours it's well over 90% likely. The odds of detection go up pretty quickly from there. So you go from guaranteed success to almost certain failure with little space in between.

That behavior might be OK in many cases. If so the DM might as well simply choose whether the detection occurs at all, and if so where it occurs. This can still be done randomly, but skill checks aren't really the most effecient way to do it. If detection occurs then skill modifiers can still be used to establish how far away the opponent is.

The other way to handle it, and this is what I would usually do, is after the initial opposed skill check only make a new roll whenever circumstances change. A check would be made every time the group stops and listens, or if the stalker speeds up to shorten the distance, or a new ground surface is encountered, the wind dies down, after combat, etc.

 

[Infiniti2000]

I agree with Slobber Monster. I'll also point out that the use of the term "DC" is incorrect for opposed checks. The creature makes a Move Silently check, but this is not a DC for the Listen check. DC's and opposed checks have different rules on ties.