Destroying a stone bridge?


Pathfinder Second Edition General Discussion

Silver Crusade

About how long do you think it would take someone to do enough damage to cause a stone bridge to collapse? Running a game involving a battle throughout the city, and was thinking that one encounter would be them defending someone/trying to stop someone from dropping a bridge, to cut off one of the possible avenues of attack.


3 people marked this as a favorite.

That should happen at the speed of plot.

Probably using some sort of Victory Point system to mark time.


Pathfinder Rulebook Subscriber
breithauptclan wrote:

That should happen at the speed of plot.

Probably using some sort of Victory Point system to mark time.

Agreed. If you did look at it mechanically it becomes tricky. There's a line in damaging objects that a GM can rule you simply don't have the weapons or tools needed to damage an object. So what's the right tool? A striking long sword? A great pick? A monk's fist? By sheer damage numbers most striking weapons could break through a stone structure eventually. So how do you feel about a bow and arrow doing it at high levels?


1 person marked this as a favorite.
Pathfinder Roleplaying Game Superscriber

Stone structures are listed as having 14 hardness and 56 HP per 5-foot cube of material, so depending on the attacker/width of the bridge it might take a while. If the bridge is supported by something it might be easier to just take out the support and let gravity pull down the bridge.

Using downtime to just mine the bridge using appropriate tools like a pickaxe would probably still take quite a while, maybe a day per 5-foot cube being removed with a few people working on it.

Carving through stone isn't easy in the slightest, even with reasonable strength and determination, but smaller or already vulnerable bridges could be broken faster if you want to justify a particular timing. Or they could have magical/otherwise specialized tools to destroy the bridge beyond brute strength.

EDIT: Also worth noting that the bridge would be broken at half-HP, so they wouldn't need to completely destroy the thing if they just wanted to stop folks from using it. Particularly with breaking the supports, as that'd be enough to prevent the supports from working and might collapse the bridge.


Let assume that whomever is trying to destroy the bridge is smart enough to know you shouldn't use weapons to do so.

The best solution is probably a number of acid flasks to dissolve away the stone. I would probably rule the stone hardness doesn't apply against the acid.

If you secure enough flasks of acid you could probably rapidly destroy a bridge.

The contest though could be stopping the flasks from reaching the site.

Silver Crusade

Didn't even think about acid, this was going to be a couple guys with pickaxes at work on the stone supports, might try and doing the acid instead. Or some sort of acid elemental


Transmute Rock and Mud, level 5 on arcane and primal lists.

Liberty's Edge

That one probably won't work, since it needs to be unworked stone (and non-magical, and unattended). Most bridges that are sturdy enough to need more than the aforementioned "two guys whacking at it with pickaxes" are likely made up of more than a bunch of rocks stacked on top of each other. If it's a natural arch, of course, you're golden, though you may get a disapproving look from your local druid.

Silver Crusade

1 person marked this as a favorite.

Well, to be fair, the guys whacking it with pickaxes is mostly to cause enough damage to make it crumble under its own weight, or to take out a central pillar if it's made of wood.


2 people marked this as a favorite.

Disintegrate.

Silver Crusade

Okay, maybe i should have been a little more clear, but this is low levels (and, strictly speaking, D&D 5E). The characters are 3rd level, so no, we aren't throwing 5th level and up spells. Some of us play low level.


1 person marked this as a favorite.

Well, I don't know what D&D 5E has for options similar to Victory Points. But I would still recommend something like that for determining how long it takes and if the players succeed at their task or not. Rather than poring through detailed minutia to try and determine what how many seconds, minutes, or hours it will take to destroy a stone bridge given any number of creative and inventive solutions that the players or NPCs have available and manage to come up with.

Abstract that. This is a storytelling game. Not a reality simulator.

Liberty's Edge

That does clear things up a bit. That said, you did post this in the forum for Pathfinder 2e, whereas you might get more useful answers in one of the D&D5e subforums. As general advice, without regards to any particular system, I agree that it should take these saboteurs exactly as long as the plot requires, ideally with the party arriving at a critical moment (giving them to opportunity to prevent the bridge from being severely damaged or totally destroyed, something along those lines).


Earthquake

Silver Crusade

Losonti wrote:
That does clear things up a bit. That said, you did post this in the forum for Pathfinder 2e, whereas you might get more useful answers in one of the D&D5e subforums. As general advice, without regards to any particular system, I agree that it should take these saboteurs exactly as long as the plot requires, ideally with the party arriving at a critical moment (giving them to opportunity to prevent the bridge from being severely damaged or totally destroyed, something along those lines).

Yeah, sorry about that, far more familiar with the Paizo forums, haven't been on the Wizard forums since the final days of D&D 3.5. Don't even know they had one on here, if they do. I'll probably have this done more in waves than anything else, or just see what works out in game


Val'bryn2 wrote:
About how long do you think it would take someone to do enough damage to cause a stone bridge to collapse? Running a game involving a battle throughout the city, and was thinking that one encounter would be them defending someone/trying to stop someone from dropping a bridge, to cut off one of the possible avenues of attack.

Depends on thickness, location, and area it covers. To collapse a bridge, you would have to target its upholding structures, and destroy those, causing the bridge to collapse due to lack of support. A great way to sabotage an invading army by doing this without them knowing as they invade.


What about using passwall or disintegrate to put holes in all of the support columns?


Yqatuba wrote:
What about using passwall or disintegrate to put holes in all of the support columns?

Would be more effective than trying to beat or pick away at it, assuming the support columns aren't somehow like 50-100 feet in diameter or something (such as a Colossus Bridge).


2 people marked this as a favorite.
Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Roleplaying Game Subscriber
Losonti wrote:
That one probably won't work, since it needs to be unworked stone (and non-magical, and unattended). Most bridges that are sturdy enough to need more than the aforementioned "two guys whacking at it with pickaxes" are likely made up of more than a bunch of rocks stacked on top of each other. If it's a natural arch, of course, you're golden, though you may get a disapproving look from your local druid.

You don't cast it on the bridge. You cast it on the earth supporting the bridge. Strip the foundations away in a mudslide and most things won't remain standing.

Liberty's Edge

Oh, duh!

Silver Crusade

Yqatuba wrote:
What about using passwall or disintegrate to put holes in all of the support columns?

Yes, but again, low magic, at this point talking high level people in this town might reach level 6.

I mean, I AM running in the Forgotten Realms, but not every town has 10 wizards in their teen levels


You could also make it so that the players have to defend the saboteur team from enemy troops while the saboteurs desperately try to install explosives at the base of the pillar.

How much damage do the explosives do? A plot amount !


Pathfinder Adventure Path, Lost Omens, Rulebook Subscriber

Depending on the type of bridge, you may be able to target a smaller component like removing a keystone. Some bridges have multiple keystones.

Using Engineering knowledge, mauls and wedges to make a gap, then placing acid or alchemical items.

If the players are defending the sappers, maybe the sappers started beforehand and the heroes just need to hold out for 5 rounds. Then there can be Dex saves to clear out before the rubble takes them or risking being caught on the wrong side of the bridge.

If they are trying to stop them, give a similar timeframe. The guard comes running to tell the heroes that people are going to destroy the bridge, and the heroes have 10 rounds to get over there and stop it. Do they stay and fight the current bad guys or retreat to save the bridge?

Community / Forums / Pathfinder / Pathfinder Second Edition / General Discussion / Destroying a stone bridge? All Messageboards

Want to post a reply? Sign in.