Atm writing on a Version with a bigger Tutorial.
When approaching a new room you Always Roll 4D6.
The First die decides what is on the other door: 1-3 corridor, 4-6 Chamber.
In Addition to that, the exact number determines the Type of door.
1: Locked door into corridor
2: door into corridor
3: No/Missing door Leading into corridor
4: No/Missing door Leading into Chamber
5: door into Chamber
6: locked door into chamber