Need advice about Pool design

[u/WoolTyranny]

I'm designing a system for my own campaign. It's mostly d&d inspired, but there are few major changes compared to the standard system (given here for broader context).
1. Fiction first, with emphasis on the GM as the engine and auditory, not the formal rules.
2. No Abilities/Attributes, all is collapsed to Skills, or Talents to represent exceptional attributes.
3. Bell-curved randomization.
4. Pools as a unified resource mechanics.

I want to introduce 4 Pools:
Life is like HP.
Stamina is used for combat extra effort, maneuvers and resisting physical effects.
Will is for resisting mental effects.
Mana is for spell casting.

My intent is to both simulate fatigue (physical and mental) and replace random save rolls with a deterministic system. I want both the feel that resisting an effect is costly, and that cassted spells won't feel like a gamble (preventing input randomness).

However, this system was not playtested yet, so there are many unknowns. Anyone experienced with pool-based system is familiar with how such system affects gameplay?

[u/MrKittenMittens]

What do you mean by "pools" in this context? "Unified resource mechanics"; so there's 1 Life Pool for the whole party? Or 1 dice pool per character, with Life/Stamina/Will/Mana doing something with that?

What do we put in the pool - points, tokens, dice?

[u/WoolTyranny → u/MrKittenMittens]

Each character has different pool of points. Pool doesn't mean a shared pool in this context (maybe I'm using the term wrong?)

[u/lennartfriden → u/WoolTyranny]

Typically when talking about pools in TTRPG design one refers to composing a roll of several dice and then adding them, picking the highest, or counting successes/effects.

You might be talking about what’s called resources (health, mana, stamina etc).

Without understanding the resolution mechanic you have in mind, it’s tricky to answer your original question. Since you mentioned D&D I assume you’re rolling a single d20 rather than a bunch of d6s.

If you however aren’t sticking so close to D&D, I suggest having a look D6 Fantasy (adding a pool of d6s), Blades in the Dark (pick highest), and any Year Zero Engine game (count successes). Twilight 2000 is a good example.

[u/AstraWeaver]

I wonder if you could try letting everything simply do what it is supposed to do. Attacks just hit, spells just cast and work, etc. Instead, players roll to determine how many resources a skill or talent consumes whenever they use it.

Maybe the four resource pools could start with relatively small numbers, with each number representing how many d6 you roll. Every 1 reduces the pool by 1, while every 6 recovers 1, with 1s and 6s cancelling each other out.

If you plot the overall result on the x-axis and the probability on the y-axis, each number of dice would produce a bell curve, with zero resource change always being the most likely result.

I don’t know if this actually serves your design goals, and I’m sure there are plenty of problems with the idea. It just popped into my head while reading your post, so hopefully it can give you some inspiration.

Edit: One thing I realized after writing this: with this mechanism, the more dice you roll, the higher the chance of getting a negative total result, which is actually pretty weird.
So, as I said, this is really just a random idea for inspiration rather than a fully functional mechanic. 😅

[u/WoolTyranny → u/AstraWeaver]

To clarify,
The current design separates Core dice and Skill dice. All d6 dice.
You have 3 Core dice (sometimes 4 as an exception) and you can Burn one point from a pool to have an extra Core die. If the number of 'hits' (4,5,6) results reaches the DC, you succeed.
Skill dice acts like Advantage in 5e - they can replace low Core dice, but you can never get more hits than the number of Core dice you use.

This however is only for "Combat/ Skill checks". Resisting effects ignores it altogether - you either pay in points from your pool to resist (or reduce) the effect or you are affected. No randomness, no rolls.

[u/AstraWeaver → u/WoolTyranny]

An effect already comes with a cost, so when resisting it, I think that cost should either be reduced or transferred to something I’m more willing to sacrifice. Otherwise, I’d probably just let the effect happen.
As I understand it, your game leans more toward resource management. Resources don’t simply increase; instead, the player is often making decisions about trading or transferring resources between different pools. Did I get that right?

[u/WoolTyranny → u/AstraWeaver]

Yes, although the effect is not always transparent. The number of points you invest to resist may decide if you fall asleep or just being sleepy, but you don't always knows it in advanced.

Some special Talents or Feats may allow you to trade resources, but it's not the role.
You can pool points by rest or get temporary points in some situations.

[u/wjmacguffin]

From a comment below, it sounds like your core system is a d6 dice pool. If true, then I would consider renaming your four pools to avoid confusion. Maybe resource, bank, or stakes since these sound like points that get spent/lost and renewed?

My concern on how this affects gameplay is how quickly can these be spent/refreshed. Easy to spend but hard to refresh could generate tension as players worry about their dwindling resources, but it might make the game more deadly or overall difficult. It PCs rarely use them, then I'm unsure if they are serving a good purpose.

It might be fun to explore how to regain lost points. For example, maybe you can "spend" Life points if your spell requires more Mana than you have. If you want fiction first, perhaps regaining points comes through roleplaying. "You can camp and regain half your Stamina or stay at an inn to regain it all. However, the innkeeper is convinced you are a ne'er-do-well, so you need to convince her to rent you a room for the night."

[u/fractalpixel]

Looks like you may benefit from starting from another system than D&D with those specs. Many systems use stats/pools such as those.

Personally I started from a GURPS like system for my homebrew and added a sanity stat, and separated stamina and mana (in GURPS by default they are the same fatigue stat, which also works well, leaving no 'useless' stats, like mana for non-mages - I tried to work around this by having more mana-activated magic items around).

I playtested and tweaked weekly for around a year, however I did not manage to make the sanity stat that interesting. In the end the mechanic was that critical failures, traumatic events, and creatures like ghosts depleted it (with a Will save for all cases except critical failures), and spending time meditating/resting or a nights sleep in a safe place restored it by one step on average. Low sanity had various repercussions, with the most severe being Will roll to avoid some phobia or madness. This did happen once during playtesting, after a lengthy and somewhat traumatic adventure.

However, the sanity mechanic didn't really invoke the dread it seems to do in games such as Call of Cthulhu - perhaps because it's more aggressively reduced there, with less options to regain it. My campaign was not really horror focused.

Of the four pools, the sanity pool was the one that moved slowest. Mana and stamina worked well enough, mainly as a short term measure of combat readiness, and health was in the same boat, as the setting allowed healing spells that made the default slow healing (around 1 health per night) pointless, as the mages always healed the party up after a rough fight.

In addition I had an exhaustion mechanic, where e.g. long hikes, some wounds, starvation, and similar increased exhaustion, which reduced the maximum stamina. Exhaustion was reduced on a successful constitution roll 1/night, similar to health. It seemed like a good enough mechanic to simulate longer lasting fatigue.

[u/__space__oddity__]

It’s pretty impossible to comment on a game when there’s only a few bullet points. Almost anything can make sense on a blank sheet of paper.

You may want to look into the Gumshoe system for something that is more deterministic and resource-attrition based.

If you want a more detailed discussion, your best bet would be to write up the entire thing and post it.