D&D 4E Secret Doors in 4E

[Silverwave]

But i let them take 20 when there's time, rather than rolling over every inch of the goblin warren.

It's fine to allow "take 20" in this particular case, but don't forget that RAW, you can't neither "take 20" or retry on a missed perception check.

 

[Nytmare]

It's fine to allow "take 20" in this particular case, but don't forget that RAW, you can't neither "take 20" or retry on a missed perception check.

Learn from my mistakes!

http://www.enworld.org/forum/d-d-4th-edition-rules/251728-detecting-magic-items-2.html#post4700007

 

[TarionzCousin]

Learn from my mistakes!

http://www.enworld.org/forum/d-d-4th-edition-rules/251728-detecting-magic-items-2.html#post4700007

Aha! You must mean this:

The PCs scour the room,
rolling a lot of Perception checks. Unless the characters
are under a time constraint, assume that they’re
going to roll a 20 eventually, and use the best possible
Perception check result for the party.

 

[Silverwave]

Again, they contradict themselves.
PHB p.186 under perception

Failure: You can’t try again unless circumstances
change.

Searching: When actively searching an area or looking
for something specific, assume you’re searching
each adjacent square.

So, you could only make one roll per 9 squares. The take 20 couldn't apply.

Yay to design team that don't speak to each other.