Door

It's an often missed rule that all dungeon doors are quite large, difficult for PCs to open, and easy for the dungeon's denizens to open.1) It's important to read all the dungeon door rules, which are found on DMG 97. All dungeon doors MUST be rolled for in order to open. Up to 3 characters can try to open a standard 8' wide door in one check – each character rolls separately.

Base types:

Type	To Open	Breaking
Wood	1 success	1 turn, 3 WM checks
Stone	1 success, chance reduced by 1	6 turns with tools, 3 WM checks/turn
Metal	1 success, chance halved (rounded down)

Modifiers:

Door State	Open Modifier	Break Modifier
Stuck	Chance reduced by 1	–
Sturdy	–	Takes 2x as long (with 2x WM checks)
Locked (wood)	Two simultaneous 1s required	–
Locked (stone)	Three simultaneous 1s required	–
Locked (metal)	Only possible with STR 18/91+ equivalent or magic	–
Barred	Only possible with STR 18/91+ equivalent or magic	–

Opening

First determine the base chance based on the type of door (above). Then apply any modifiers (also above).

STR 18/91+

For exceptional strength of 18/91 or higher which affords open chances of “1-4 (1)” or “1-5 (2)”,2) PHB 9. treat each of those as “steps” for purposes of reducing chances by 1. For example, “1-5 (2)” reduced by 1 would go to “1-4 (1)”, and “1-4 (1)” reduced by 1 would go to “1-4”.

After opening

Any character who assisted in opening the door is in the room or corridor beyond afterward.Ex3) Without a rule like this, undesirable gameplay arises where fights may happen in doorways, or questions of character position will arise. With this rule, positioning is clear, and encounters can begin inside of the room proper.

Failure

A failure to open the door means anything beyond the door is alerted to the attempt and cannot be surprised by the opening party.

Door checks can be made indefinitely until they succeed, each attempt taking 1 round.

Closing time

Dungeon doors always close at the end of the following round unless a character spends the round holding it open, during which time they cannot fight, cast spells, etc. Dungeon doors will also stay open if a monster wants it to stay open.Ex4) DMG 97 says, “all doors are hard to open and hard to keep closed or open for player characters”, and this rule simply adds a definitive number to it.

Spiking

There are no official rules for this. The following system is suggested:Ex

Spiking doors takes round per spike and makes noise, triggering a wandering monster roll for every spike. Spikes are not recoverable. A monster can remove spikes instantly, effectively ignoring them and operating the door normally, regardless of the monster's size.

Wooden doors: 1 spike holds 2d4+1 rounds, 2 spikes holds 2d4+1 turns.

Stone doors: Double spikes required.

Metal doors: Triple spikes required.

Rolls are made privately by the DM, similar to turning duration rolls.