Jacen said:
I have already answered to this. Because the players desided to surprise the NPCs.
This is not a rules answer.
There are two requirements here. The players decide to surprise and the DM allows for surprise. The players do not get to decide on their own.
You claim that opening the door results in auto-surprise, but so far the only reason you have given is because the players decide to surprise the NPCs.
Err, so what? Players decide to do things all of the time, but we have dice rolls to determine success.
Jacen said:
It is more likely that PC does something that results door being opened fast. Before that is opened the combat starts. If it is opened normaly there are spot checks before combat starts.
Fast, slow, doesn't really matter.
It just comes down to:
1) Is the door opened before initiatives are rolled?
a) Yes. Combat has not yet started. NPCs get checks to see if they notice the door being open (if it is opened fast, the DC should be low; if slow, the DC should be higher).
b) No. Combat has started. In order to open the door, the PCs have to use up a Standard Action.
The speed of the door opening is not relevant to the discussion except for how high of a DC is required to notice that door opening. There are no rules that opening a door quickly gives auto-surprise whereas opening it slowly gives checks to notice it being opened.
You are adding:
c) Yes. Combat has not yet started. NPCs do not get checks to see if they notice the door being open because of DM fiat (rule zero).
The rules in the DMG (that I quoted earlier) suggest that DMs give characters a chance (i.e. checks) to notice stuff like this. Your solution c) here ignores that suggestion in the DMG.
The reason a) is more RAW correct than c) is due to the fact that combat has not yet started. Bottom line.
If combat has not yet started, there is no rules reason for not giving the NPCs a check, but there is a rules reason to do so. What is your rule reason for not doing so? So far, you have only stated it is because the PCs want to surprise the NPCs. That is not a rule reason.
It still comes down to "Why is opening a door an action that automatically surprises when other actions do not?". You might think you have answered that question, but you have not. At least not that I could understand your answer.
"Because the players desided to surprise the NPCs."
WHAT???
