ZEITGEIST How to make an Eschatologist Bomb

I've been meaning to post this for a while, but I have been dragging my feet. I finally decided to post this (incomplete) as a lot of people appear to be reaching chapter 5. So here it is:

How to build an Eschatologist bomb:

I was looking at the finale to the Eschatological Terrorist Thread and really liked the bomb game. I like the incorporation of puzzles into my campaigns as it breaks up the monotony of exploring dungeons. The game was simple enough, diffuse the bomb using your wit and skill checks so that you do not kill yourself and all the hostages. But I thought it was a bit...anticlimactic. Just roll a few skill checks and BAM it is diffused.

But what if you had to diffuse the bomb manually...and you had a way to build the game...
Could my real life players accomplish what their fantasy counterparts would do?

Well, I had a bit extra time on my hand and decided to BUILD the game
(Disclaimer: I am not an electrical engineer nor a coder...just a dude with too much free time on his hand
There are probably much better ways of accomplishing this, but this way worked for me)

I took only these descriptions into account when building it:

Inside, twenty-nine rune-inscribed steelwires criss-cross an amberglass drum that holds forty gallons of alchemicals. The drum is divided into eight sections, each filled with a differentsubstance.The runes on each wire are in Dwarven, and describe the connection,such as “Frayed Chronosomia to Phlogiston.”

One wire is engraved sim-ply “Black,” and it runs from the top of the barrel to the floor.
(I ommited this one as I did not want to actually shock my players, so no need for the "Ground")

Every few seconds one of the twenty-nine wires starts to glow, andthen the two chambers it connects admix some of their contents. Thewires glow in no discernible pattern over the course of four minutes, andtouching one of the wires while it is live will deal 1d6 electricity damageto the character. The wire labeled “Black” never glows. It acts as a magical ground, and a character holding it can touch any of the wires withoutconcern for taking damage.

The mixing can be stopped simply by cuttingall the wires. However if you cut a wire while a chamber on either endhas any of its wires active, the whole thing will detonate. For instance,if you want to cut a wire that leads from Witchoil to Aether, and whileyou’re cutting it any other wire that connects with either Witchoil orAether activates, you’ll set off the bomb. Figuring this out requires a minute of examination (Disable Device or Knowledge [arcana] DC 28). Technologist PCs gain a +5 bonus to thischeck. Examination at the safe house might have previously determinedthis. Actually pulling off the feat requires seven consecutive Disable Devicechecks that get progressively harder since you have fewer safe windows.The first check is DC 15, and they increase by 1 each, to a maximum ofDC 21. Being able to detect magic at will grants a +2 bonus because youhave more warning of which wire is about to activate. Technologist PCsgain a +5 bonus to these checks; if a technologist is just directing anotherPC, the bonus is only +2. An early detonation is less destructive, perhaps only collapsing thesubrail tunnel, but it certainly kills any PCs nearby. The danger getsprogressively worse, and by the time the train reaches Golden Point thebomb is primed enough that a detonation would create a thirty-foot widecrater. If the party manages to successfully cut all seven wires to phlogiston, they can keep the bomb from getting any more dangerous, but it willeventually go off unless they can deactivate the whole thing. The choiceis up to the party.

So I have 28 "wires" connecting the 8 barrels (check)
Every few seconds, a random "wire" glows indicating a mixing event (check - The system randomly chooses a wire to glow (LED))
You cannot pull a wire that is "connected" to a "mixing" barrel (check- The system checks which wire is pulled every clock cycle)
You win when all the wires are "cut" (all but one in my case, as it will always try to mix one wire that is not currently pulled)

(Extra flair, have a piezo speaker to make the typical "BEEP" bomb noise to cause tension)

What you will need:
Arduino Uno Board
Computer (with MATLAB 2018a or Python installed)
~100 wires
28 LEDs
4 74HC595 Chips (for LED control)
29 ~500 Ohm resistors
1 Piezo Speaker

When you hook everything up, it should look like this:
View attachment EschotologistBombGame.pdf

And you can run it in MATLAB 2018a or later using the attached code (you can obtain a 1-month free trial at MATLAB's website and will need to install the Arduino controls). I am slowly working on the Python code so this will be more accessible.
Now briefly to talk about the code.
(Note, when I talk about wires, I am talking about the "Glowing Wires" or LEDs).

How it works is that the system has a Master Table that knows what wires are currently connected. This Master Table is generated on startup so if a piece is loose (not working properly) or you want to restart where you left off (false explosion or want to give your players another chance), this Master Table will be generated from the current working wires upon start-up.

Next, the system will choose a wire from this Master Table (as this is wires currently connected) and will "Mix the barrels." (LED will glow)
This mixing will be displayed on the computer screen indicating which wire is being mixed and what barrels that corresponds to (it will be obvious as the Wire (LED) will glow). I recommending labeling the tops of the LEDs 1-28 and giving the players a master sheet to indicate which wire is connected to which barrel.

Then, about every second, the system will randomly cycle through the remaining wires to check to see if they have been pulled (disarmed). It will compare this to the master table to make sure this does not violate the "connected to mixing barrel" criteria.

If a wire violates the "connected to mixing barrel" criterion, then the game stops signaled by the piezo speaker making a "flat-line noise". A debugging message will appear on the screen indicating which wire has been pulled and how it violates the "mixing criterion" (to double check it was a true explosion). If there is no violation, the game continues.

When testing this game, it was found that the fantasy counterparts are much quicker thinkers than our real life counterparts. In the book, the wires change every ~6 seconds which was WAAAY too fast for the players. I changed it to 10 seconds but my players still think it may be too fast. You can change it to longer times pretty easily in the code if you'd like.

In order to make the game more interesting, I added three stages. In the first stage, the wire changes every 10 seconds and the system checks the "mixing criterion" every 2 seconds (indicated by a "beep").

After ~1/3 of the wires have been pulled, a warning message appears (with a warning beep from the piezo) saying "Sabotage Detected. Speeding up Mixing Rate!". (just to give a sense of tension). The wire then changes every 6 seconds and checks the "mixing criterion" every 1 second. (so faster beeps).

Finally, if ~2/3 of the wires have been pulled, the system shows "Alert! Failsafe triggered!". The wire changes every 6 seconds (no change), but the "mixing criterion" is checked every 0.5 seconds (so faster beeping again).

If diffused, an error message appears saying "Unable to mix to prime explosion. Cooldown Process Initiated" followed by a "shutdown" sound from the piezo.

Well...did my players succeed?
Unfortunately no...turns out diffusing a bomb is still pretty darn hard under duress. They got to the beginning of phase 3 and panicked. Luckily I had a back-up plan where Miller's alter ego pulled them into the Bleak Gate at the last second to stop his other half's plan (I know it was early...but I had to save my players somehow...)

If you want your players to succeed, I would recommend having the wires change more slowly, and to stress to your players that the have ~30 mins to figure the system out so they have PLENTY of time (my players panicked).

Here are pictures of the final product. (Note: my LEDs run in the opposite direction than the picture above as I wired my system backwards. Also, there are a bunch of other random chips/electronics plugged in. Those are just decoration.)


I'll try to upload a video of the system working once I finish the Python code to show how it all plays out.



This is the coolest prop I've ever seen for a game, and I'm effin' flattered to pieces to see it!

Sorry I killed your party!

Next time, see if you can get some actual phlogiston, though, to really heighten the realism.


That is awesome, having spare time on your hands can lead to acts of creative genius.
How to make an Eschatologist bomb:
Fasten a Necklace of Fireballs around his neck (like a necktie) and install a dead-man switch such that they will explode if he stops talking.
If you found him excessively annoying, give him a countdown timer that measures when he takes a breath, drinks water, &c until enough 'silent time' has passed.

Extra flair: digital display attached to the timer, which flashes after it gets past "0 0 7"

- This suggestion courtesy of Heath Ledger's Joker. (and a famous Demon Lord)