Innovation on a trap idea

[Doomboy911]

I saw this one trap in one of the books it was a bridge across a chasm and once you get so far crossbow bolts fire down. I thought of how to make it more dangerous have it so the first bolts that fire down contain oil so when they hit, they cover the bridge slowing everyone down. So as they progress across it the arrows fly down and it takes longer to get across. Now if you wanted to be particularly mean you could have the last bolt in the set be a flaming bolt to light the oil burning the bridge entirely. This is just an idea what do you think?

[drengnikrafe]

What do the PCs do when/if the bridge burns down, they are on the first side of it, and are unable/unwilling to jump, and have no means to fly?

Or, if the bridge hasn't yet burned down... nonmagical fire is only 1d6, IIRC. What level would this trap be at?

As for the idea itself... Yes, that's quite clever, and I like it. I'm just a little worried about reprocussions if things go poorly.

[TruorTupnm]

Instead of aiming for the PC's, it aims for the planks, gradually cutting people off from each other or one side or the other.

In addition to being fired upon, the entire bridge lowers, requiring jumping and climbing skills to get to the other side?

[Doomboy911]

You could make it seem like a straight and clear path to whatever the party's goal is ex: a sword or castle. Than should they fail to check out the bridge they fall a good couple of feet and get injured and I have the idea that the bridge burning leads to both walls getting caught on fire than they have to go around to reach their goal.

[Reaper_Monkey]

Why would this sort of trap exist though? The practicalities of it seem minimal and its generally overly complicated.
If you didn't need the bridge in the first place why is it there? If the bridge is designed to be there simply as an elaborate trap then why rely on hoping that they will be in the danger zone if the oil gets ignited? Why have the destruction of the bridge so uncertain and slow? Why have the arrows deal less damage just to try cover them and the bridge in oil rather than using a more straight forward method of doing the same thing?

You could just have a vat full of oil which is triggered half way down the bridge which pours from directly above (soaking the players and the bridge) and have all the arrows be flaming, or easier just have fire bolts/balls targeting anyone on the bridge mounted up high.

This trap assumes the bridge is made of stone (and so doesn't burn down) and the person who owns said bridge is immune to fire (and would avoid the oil trap in the middle merely to save the effort of refilling it). It's simpler and makes sense story wise.

The best traps make sense, both in how they work and why they are there, as it allows the players to gain some insight into the traps before they are encountered. For instance a villain that can breath underwater wont think twice about having an unavoidable trap flood a section of corridor if it stops some intruders disturbing them as it doesn't cause them any real inconvenience.

[Doomboy911]

Well its one of those old rickety bridges not stone its made to burn through it. You could make it so the enemy has some form of flying ability so he can just dodge the bridge all together and any intruders trying to invade have to cross the bridge when it goes off the enemy has time to attack from above or run away since it will take time for them to get to you.