# What are the mechanics for monsters trying to force a door shut when PCs are in the way?

I'm going to be hosting an encounter where the PCs will enter a room. Behind the fully opened door in a hidden niche are three monsters that will attempt to close the door when the big bad gives the sign. My question is what is a simple way to handle the mechanics around the forcing of the door. The door itself is hinged on one side. By closing the door the three monsters are hoping to seal whoever is in the room in and whoever is out of the room out. The following things are what I am concerned with:

• What if one or more PCs is in the way of the door?
• If the PCs have not perceived the monster then there will be a surprise round where the door closing will occur. How does this affect the scenario?
• What's a fair way to include one of more PCs getting injured if the door closes on them (i.e. like getting an arm stuck in the door).

Thanks,

• Firstly I'd like to hear more about the door. Is it hinged, or does it just slide to one side. Is it set withing the wall or does it stick out from it. Basically, what is the intended result of closing the door? Jul 14, 2013 at 3:23
• @Mitharlic, I've updated the question with the details that you were looking for. The door is hinged on one side and the monster are trying to seal the PCs in the room in the room and out of the room out of the room. Jul 14, 2013 at 12:37

I’d just rule it as a bull rush; moving people who don’t want to be moved is what Bull Rush is for. That there is a door in between them during the pushing only means the monsters cannot follow the players to push them further once the door is shut.

If it’s a big, wide door (i.e. 10 ft. or longer so multiple creatures could push it together, and multiple players could block it), I would modify the check slightly: I’d make it 1d20 + the sum of all the pushing monster’s CMBs, against a DC of 10 + the sum of the CMDs (minus 10) of the players in the way. That way all of the monsters’ and players’ stats come into play. In order to act together like that, though, the monsters should be required to have their turns all in a row.

This is where catching the players unawares helps: during a Surprise Round, those surprised don’t get a turn. If the players are not surprised, the monsters with higher Initiative have to Delay so they can act as one. That can give the players a chance to act. Also, flat-footed players (i.e. before they get a turn) cannot make attacks of opportunity (unless they have Combat Reflexes) that the monsters may provoke for this maneuver, and also lose their Dex bonus to CMD if they have one (and Combat Reflexes doesn’t improve that one).

For the damage, I probably wouldn’t bother; seems below 3.x’s abstraction level to me. If you want, though, you could probably stat the door as a trap that makes an attack roll when slammed shut on someone.

Note: if there isn’t anyone in the way of the door, closing it is typically a Move action.

If the PCs are spaced such that no one's in the square "just inside", in the path of the door, then seems like it's an automatic close unless some PC has initiative and detects this via Perception or whatnot.

If there is someone in the path of the door, then it's a bull rush attack on that person. It seems pretty unlikely they'd get a body part stuck in the door (given that's not what the monsters are trying for), so that's mainly on a natural 1 on the PCs' part (or if they say specifically they want to stick a foot in the door or whatever), in which case I'd make it do door-plus-all-three-monsters'-strength-bonus improvised weapon damage - I'd rate it 1d6 for crappy internal wood door, 2d6 for stout wooden door, 3d6 stone, 4d6 iron or something.

Now you could always stat it up as a trap if you were wanting to be super anal (which you may, since you're asking this question instead of just ruling on the fly in the game). In which case you'd just set the DC and damage according to the CR rules - for example, CR10 Massive Crushing Door Trap.

• The damage seems high; a stone door doesn't seem like it should be a better weapon than a greatsword... Jul 14, 2013 at 16:19
• It's all about the mass. It's not "better" in that it's super hard to hit someone that isn't looking to get hit, but it is certainly going to convey more impact to the subject. It'll easily sever a limb. Jul 14, 2013 at 17:22
• I thought bull rush might be the way to go. I think I'll work with that. I'm not particularly strict, I just want to make sure that I have a fair mechanic lined up to keep my PCs happy. :) I went with @KRyan answer because he detailed it the way I will end up running it. Jul 15, 2013 at 1:13
• "Easily sever a limb" sure but so will a 1d8 longsword - peasants only have 1d4 HP anyway. If I have somebody hogtied and chop their head off w/ a greatsword, I only deal 2d6+STR x 2 damage, which seems to me should be more damage than a door deals. Jul 15, 2013 at 8:00
• @medvih Chopping off someones head obviously should not abide any hp rules - it should be a kill, unless the guy is some kind of hydra. I agree with mxyzplk, the door can have big damage. The energy of the hit is defined by mass and speed. If the monsters swing the door as fast as you can swing a sword, youre into a world of pain if you get your foot in the way, as a longsword should weigh at most 2kg, and solid door can beat that 10x.
– K.L.
Jul 15, 2013 at 11:00