Nail said:Search: Take 20. No roll necessary. Either you fail, or you succeed.
That doesn't really work for traps, since there is a penalty for failure (you set off the trap). Besides, Taking 20 isn't really the same thing as being unable to fail. One is taking the time to do it right, the other is automatically succeeding every time you try. I see what you're saying, in that Taking 10/20 are non-roll situations, but they're still fairly limited in the situations you can use them. I don't consider that the same thing as character being unable to fail at something.