D&D 5E Introducing the COUNTDOWN DICE Mechanic!

[Dausuul]

Umm... shouldn't for 1 die it be less than 6? I think of it if I roll 5 times, by that fifth roll I should more often than not have gotten a 6. Which means the average would be less than that. But... I'm very uncertain...

Looking at your question again, I realized that the median is more appropriate than the mean here. I just added it to my original table:

DICE	MEAN (AVG) TIME	MEDIAN TIME	STD DEV
1	6.00	4.00	5.46
2	8.73	7.00	6.13
3	10.56	9.00	6.39
4	11.93	11.00	6.54
5	13.02	12.00	6.63
6	13.94	13.00	6.69
7	14.72	13.00	6.74
8	15.41	14.00	6.77
9	16.02	15.00	6.80
10	16.56	15.00	6.82

 

[Weiley31]

So basically:
Roll a number of D6's.
If you roll a 1, remove it from the Clock Pool of D6's.
When you run out of D6's, TIME IS UP!

 

[UngeheuerLich]

Looking at your question again, I realized that the median is more appropriate than the mean here. I just added it to my original table:

DICE	MEAN (AVG) TIME	MEDIAN TIME	STD DEV
1	6.00	4.00	5.46
2	8.73	7.00	6.13
3	10.56	9.00	6.39
4	11.93	11.00	6.54
5	13.02	12.00	6.63
6	13.94	13.00	6.69
7	14.72	13.00	6.74
8	15.41	14.00	6.77
9	16.02	15.00	6.80
10	16.56	15.00	6.82

That is a very interesting point. I know the geometrical distribution has an average number of rounds until rolling the first 6 of 1/p = 6.
But i never had the idea to look at the mean here, which indeed has its merits.

 

[Atomoctba]

I use a different, but slightly similar mechanics on my games. Everything the players do anything that takes time (search the room for secret doors, loot a treasure, stop to first-aid themselves, &c), I roll a d6. If I did not roll 1, it just take the time nothing more. But next time they delay to do something, I roll 2d6. No "ones", the game proceeds. Next time, I will roll 3d6 and so on. So, in a sense, I "build" a pool rather than countdown it. If I roll any "one", something occurs and the pool resets again to 1d6 on the next time I roll it.

But what is the "something"? It depends. It can be a random encounter, the bomb explodes, the ceiling of that unstable ruin colapses, and so on. Or the "one" can also build something else that takes time. For example, first 1 rolled, the volcano erupts. Second 1, the lava reaches the dungeon where players are. Third 1, all the exits are sealed by lava now. Or: the bad guys are doing a five step ritual in the heart of dungeon. Each time I roll 1, one of the steps is completed. And I always roll all dice in plain view of the players. Why? To show them that each delay can have a consequence. They are taking time when time is at the stake.

Credits to original idea to the Angry GM blog.

 

[Nine Hands]

Countdown dice pools are a mechanic which I initially used in my game What's OLD is NEW, and later included in Level Up: Advanced 5E. It's a mechanic which can be used in any game system as long as that system uses (a) dice and (b) turns or rounds. With a heist-themed anthology on the horizon, countdown dice pools could be a useful trick to add tension to encounters or scenes. I've used these in most every game I've run in the last decade or so.

A countdown dice pool is used when there is a time limit on an event, but you (including the DM/GM!) don't know when that time will run out. A ticking bomb, the time until the guard rounds the corner, a dungeon collapsing as you try to escape it--anything where the expiry time is unknown.

Here's how it works: you form a dice pool of d6s. The size of the dice pool can vary. Each round you roll the dice pool, and remove any 6s. When the dice pool is depleted, the countdown ends -- the bomb goes off, the guard comes round the corner, the dungeon collapses.

It's super simple and is great at adding tension to the game. You can even mess with the pool: change the time interval to minutes, hours, even days or more; or certain actions might add dice or remove dice, speeding up or slowing down the timer. Maybe you're trying to disable a trap before it goes off, and you fail a check, cutting the wrong wire, which removes a die from the pool immediately! Or perhaps your pool represents a disease, rolling daily rather than each round, with dire outcomes when the pool reaches zero dice, and an excellent medicine check adds dice to the pool while time depletes it.

WOIN Rules Reference Document - Countdowns

A countdown takes place when there is an unknown time limit before something occurs. It is used in the following situations: Death. An unconscious character uses the countdown mechanic as he slips towards death. Illness. Disease and illness use the countdown mechanic as symptoms worsen. Drowning

www.woinrules.com

Countdowns | Level Up

a5e.tools

I use these in my mecha game, we call them ammo dice. Depending on how much ammo you fire, you discard rolls of 1, 2, or 3. Once you are out of ammo, that weapon can't be used anymore. Time to switch to another weapon.

 

[Kannik]

Ever since I saw this concept in the WOIN ruleset my interest has been piqued! Don't know if I have the statistical chops to work it, but it'd be grand to get the median/expected length for pools for die sizes 4 through 10... would make it easy to find the right one for the desired tension and outcome in a game.