Is there a good guidleline for "Assumed Character Actions" vs Necessary Descriptions?

Question

It should go without saying that to some extent in any given role playing setting there needs to be a general set of assumptions made about the actions of the characters. Some of these are naturally built in, for instance in current editions of D&D passive perception exists to make it clear that your characters are always at least partially aware of the world around them. Generally it helps avoid the players having to state with repetition that they are not walking through a dungeon with their eye's and ears closed, and are wary that such places can contain monsters and booby traps.

However a number of GM's and even written material for the same system will omit this benefit of the doubt for specific circumstances. For instance in Hoard of The Dragon Queen a hidden door is located beneath the rug in a specific room. The text instructs that unless the characters specifically look beneath the carpet no level of success on search roll will turn up the door.

So what is the best method for setting the cut-off point to make it so that players don't feel cheated:

"Of course I would look behind the tapestry during a search! I looked under the table as well as on top of it if that wasn't made clear by my effort to take time searching the room."

But the GM can still reasonably direct towards interacting with the world via means separate from skill checks.

"I make an intelligence check to develop a plan to get across the raging river with our allotted resources"

Obviously to some level this needs to be a group agreement with minor concessions in the general social contract of the group, but I am looking for a method that can keep gameplay both efficient and engaging. The goal being to make players WANT to interact with items and rooms that are relevant and quick to pass by fluff.

Answer 1

The best guideline I can offer to this question has to do with how much description you provide to your players about the room/setting that they encounter.

The less description you provide, the fewer "things" there are available to search and the more easily you (or they) can roll a passive sort of detection/search check. You can choose to roll it yourself or delegate the rolling to the players.

The more description you give them of the setting, in terms of detail, the more likely it is that they need to make choices and declare what it is that they are looking at or for.

If you have particular triggers to the plot that keep the story moving, for example, you can call for or trigger a passive check when it best fits.

Pages and pages of suggestions can be written on this topic, but that basic guideline, which is what you asked for, is what I arrived at after a number of years of designing and describing dungeons/environments to players in various campaigns.

TLDR version: More detail provided calls for more detail is what they check or look for.

As you noted (great example by the way) when you write a module or a pre-plotted adventure, you can put whatever limits or trigger you want to into it for competitive or story reasons.

Answer 2

IMHO, passive perception is for things that an ordinary person would notice under ordinary circumstances. In other words, the players are going to notice a dead horse laying in the road, but unless they're specifically on "high alert" they aren't going to notice the shadows moving in the trees. Checks for Passive Perception is to see if they in fact notices things that they might otherwise miss. As the DM, I like to have characters either roll before starting down a trail or at random intervals (it keeps them on their toes).

When a player specifically says, "While the other PCs are checking the dead horse, I'm looking around at the tree line", it's safe to use his Perception modifier. In general, for most RPGs that I've played, it is never safe to assume that a player is doing anything without him telling you that he's doing it. In fact, until he changes his action, he's still doing it. This can be a very hard point to get across to new players, but sometimes you should speak to them about this outside of the scope of the game.

I've had players (in fact, last weekend) who have commented that they appreciate that I don't assume that they are doing anything in particular because it forces them to participate. One of my players commented that he preferred D&D (over another RPG that he's playing) because he feels that his character is important to the success or failure of the party. The other players told him that it's the explicit style of DMing that does that. As the DM, it makes your job easier and your players will have more fun as a result.