Knifespeaks asked:
Consider this example (really, this is about the only issue I have with taking 20):
There is a secret door, on the first level of a dungeon. It leads to the treasure room on the lowest level of the dungeon. How do you make it POSSIBLE that a player of skill 0 to find, yet prevent them from taking 20?
That's actually a really, really good question, and I'm glad you asked it.
To start off with, you have two choices regarding how difficult to find the door really is:
1. Anyone with a Search skill of 0 will be able to find the door given enough time. In this case, the Search DC of the door must be exactly 20. Note that this does not prevent the character from finding the door on his or her quick once-over, as a 20 could still be rolled.
2. Anyone with a Search skill of 0 won't be able to find the door given enough time, but will with enough information. In this case, you may set the DC higher, so long as you provide a chance to "earn" an appropriate Circumstance modifier (the DM's friend). For instance, when it comes to a DC 24 secret door, a character with a Search modifier of +0 will never, ever find it. However, should they find the Necromancer's journal, which luckily includes a quick diagram of the doorway, they recieve a +4 Circumstance bonus on Search checks when looking for that particular door. Now, the +0 person can find the door while taking 20, since he's got the clues.
We'll assume, for purposes of east, that you choose the 1st option. It's possible for a non-Search focused person to find the door if they are lucky. The next part of your problem is the ability to Take 20. There are actually quite a few ways to work around something like this.
1. Enforce time limits. "Taking 20" on a search check allows you to check exactly *1* 5' by 5' square. This will take a single character two minutes to do. A fairly standard 30' by 30' room, then, is made up of 36 5' x 5' squares. Thus, it'll take a single searching character more than an hour to search the whole room, or 40 minutes just to search the walls. After 40 minutes of searching, most of your party's spells will have worn out, you'll have burned through a couple torches, and any intelligent enemies in your area will have prepared at least a makeshift barricade. These are entirely separate from other, more difficult time considerations - perhaps the princess will be sacrificed at midnight, so you don't have time to waste checking every square foot of floor space for secret doors.
2. Make the door easy to find but hard to open. Finding the door, in this case, is only half of the problem, since you still need to get the darned thing open. Maybe there's a hidden lever (harder to find), or a secret phrase or password that needs to be spoken, that causes the 2' thick stone door to swing open. Perhaps the lever is actually located inside a nearby pit trap, or in the ceiling.
The real question, however, is why the bad guy is designing such lousy secret doors. After all, if any fool off the street (+0 Search bonus) can find it given enough time, then any reasonably-trained individual will find it almost without effort. For instance, an Elven Rogue 2 who's trained himself to find hidden things (Search +5 ranks, Int +2, Racial bonus +2, Skill Focus (Search) +3,
TOTAL: +12) will probably find it just by walking past it.
In other words, if want to keep people out of your secret rooms, a DC 20 door isn't going to accomplish much.
EDIT:
As Scion, said, above. The problem is that you think a DC 20 secret door should be hard to find.
It isn't.
In fact, a standard camoflauged *pit trap* has a standard Search DC of 24.
