Can you take 20 in 4th edition?

[UngeheuerLich]

Take 20 was the Short Rest of 3E. Unless there was substantial time pressure or a dangerous environment, you could expect players to do it constantly.

-- 77IM

and it was perfectly fine

I laso like the skill challenge idea as well as the stacking +x bonus, if you want to create tension...

but if there is no time preasure, assume a 20 if there is enough time... rolling makes no sense here...

or allow a single roll and determine the time needed to open the lock by calculating/guessing the dfference between number needed (20 or lower) and number rolled...