PDA

View Full Version : An invisible trip wire (An adventure in pulling arbitrary numbers out of thin air)



Lilithgow
2011-03-04, 08:13 AM
So, I'm writing some more stuff for my group, and I'm making a vault, and I realize that I'm having numbers quite getting the crunch on the numbers.

I've got a room full of trip wires, and I just cannot, cannot figure out the numbers for a spot check for this.

Originally, I was going for invisible trip wires (If you're making a vault, I doubt you'd skimp on things) but then I found that the spot dc for seeing an invisible unmoving object is epic spot dc40, plus diminutive item, 52, and no one in my level 10 game is seeing that without walking into it.

Now, I'm trying to go for a heist experience for my group, and so that's why there's no simple 'alarm' spell, that would just make things incredibly boring. I could just pick an arbitrary number out of the air and declare that the wires have a spot dc of 22, hard but not impossible. But then, I feel like I've just jumped away from the numbers I have down in my books.

So I was wondering what you fellow DMs have done about the situation when you just don't have the numbers?

Jack_Simth
2011-03-04, 08:22 AM
It's pre-statted in D&D 3.5 (http://www.d20srd.org/srd/traps.htm#cr1RazorWireacrossHallway).

Oh yes, and spot won't work - you need search (DC 22). CR 1 trap, though, individually.

Pink
2011-03-04, 08:30 AM
There's a very easy answer. Do you want them to be possible to find normally, OR does the party need to use special tactics or items to find them, OR should it be realistic and if the party cannot find it, so be it.

Situation 1) Possible to find normally
In this case, check the total search modifiers and set it as what you feel reasonable. If you feel that it should still be difficult to find, then set the DC that the person with the highest search mod would need to roll a nat twenty or take twenty. If you think it should be easier, continue to lower the DC until appropriate.

Situation 2) Special tactics or items
This situation works best if the players know there's invisible trip wires to worry about. Basically, you set the DC so that it reasonably is as difficult as it should be even if it makes it impossible for the party to find with one person searching, and the players must use their minds or mechanics such as Aid Another or spells to increase the search modifier. If the players prepare the right spells, like glitterdust, or are able to think of an item to buy (like a bag of flour) that might make the wires more visible, then they should be able to reasonably get past.

Situation 3) Be realistic, use the high DC
The party has ventured into an area where they don't have someone capable of taking on the challenge. They must deal with this result, even if it leads to retreating and regrouping, or having a jail escape session. This option not recommended if the plot requires them to get into the vault.

Quietus
2011-03-04, 08:39 AM
I assume the players are aware that they're headed into this heist situation, and that security measures will be taken? At level 10, they've got plenty of access to magic, and even something as simple as Detect Magic would be invaluable. Personally, I'd say that if they're ignoring these options, then they're missing out on valuable tools - Detect Magic would show, after several rounds of study, at the VERY least exactly what squares these tripwires are in. Then it's a matter of the above mentioned DC 22 search check to find/disable them, or something as simple as a fireball into the room to wreck all the wires.

Lilithgow
2011-03-04, 10:11 AM
Sounds good everyone! I'll be making sure that they know what they're getting into, and so can bring alternative methods...though knowing my group they may just walk into it anyway.

Thanks again!

Quietus
2011-03-04, 10:14 AM
As long as they know they're stealing something (justified or not), and that it's likely to be protected, it's their own fault if they set off traps meant to protect it. I mean, what, Evil McBaddy is expected to leave his vault containing the MacGuffin o' Doom completely unguarded for any ragtag bunch of rebels to come and steal it away from him?

begooler
2011-03-17, 10:35 AM
Situation 2 in Pink's post I think is the most appropriate challenge, and rewards PCs for thinking and planning.
Even though each trap's search DC is 22, with a room filled with them they are bound to accidentally walk into one they forgot to search for, or fail the check at some point. Provide them with a way to figure out that the room is going to be filled with these traps, and they will realize that they'll have to resort to something more creative than just searching. (Glitterdust, bag of flour...)

You could do this by adding a hallway into the room that has visible trip wires, then invisible trip wires, then open up into the room where they see nothing. PC's will know to be cautious about charging in.

They discover plans or a note about the room, or receive a tip from an NPC as a reward for a good gather information check when they are planning the adventure.

ericgrau
2011-03-17, 10:55 AM
Some caster spent 1,000 xp making that tripwire invisible. Ya it's almost impossible to find by normal means, but the PCs might figure it out and switch to special methods like dusting the air or searching by light touch. Especially if there's more than 1.

faceroll
2011-03-17, 11:20 AM
Some caster spent 1,000 xp making that tripwire invisible. Ya it's almost impossible to find by normal means, but the PCs might figure it out and switch to special methods like dusting the air or searching by light touch. Especially if there's more than 1.

Or smoking Solid Snake style.

jebob
2011-03-17, 04:07 PM
How about a low DC to spot the first, but to make sure that the group has found them all they'd need to roll high, perhaps up to your figure of 52.

Alternatively, don't tell them that they've found them all. Keep some random chance in there :smallbiggrin:

Funkyodor
2011-03-17, 04:21 PM
Another vote for Situation 2 as detailed by Pink. One potion/wand/scroll of See Invisible will make those tripwires stand out like in a movie. And if they don't use something like that then they'll get caught and the game turns into escape the death trap.