Deus Ex had the door thing done well. Every door (and chest and safe) had a selection of:
- A key.
- A pin-number.
- A pin-number hack difficulty.
- A computer-controlled lock (accessed by password).
- A computer-controlled lock hack difficulty.
- A lock-pick difficulty.
- A damage tollerance.
This way, most of the game could be completed by any class. Certain doors could only be opened by more restrictive methods (e.g. Blast doors only by computer, accessed or hacked.), but these were generally key story points.
The damage tollerance wasn't simply a hit-point rating. It only had one hit-point, but you needed a powerful enough weapon to bust the door. Generally, it involved planting charges on the door.