Changing Core Mechanic to a Dice Pool

[3catcircus]

So I've been kicking around stealing ideas from some other games and one thing that interests me greatly (I've only done a single, limited playtest) is the idea of using a dice pool system.

Instead of the core mechanic being d20 + modifiers >= DC, I'm thinking of going all-in using the Reflex System mechanic from TW:2013.

Basics are as follows:

1. Your DC (aka TN aka Target Number) is the controlling attribute (Str for melee attacks, Dex for ranged attacks, Int for Int-based skills, etc.) with the intent to roll less than the TN.
2. Modifiers will still add or subtract from the d20 roll.
3. Each set number of skill ranks will allow you to roll additional d20 dice when using that skill, picking the lowest of the rolls - combat would also be based upon adding skill ranks instead of using BAB.
4. A modified TN of 0 = instant success, 20 = instant failure.
5. The amount you beat the TN by is a margin of success that adds to the amount of your success. Additional dice in the pool that also beat the TN will add 2 to the margin of success.
6. AC will be just "AC bonus + modifiers" and will lower your TN.
7. Armor will also use DR - half of the base AC bonus and will be multiplied by the amount of your weapon's penetration and subtracted from total damage you cause.
8. Weapons will have a base damage of the average of the current damage and a penetration equivalent to the current critical bonus.
9. Hit points will be based solely on Str, Con, and size, and damage will be compared to multiples of the base hit points to determine wound effects (anything from a flesh wound that causes you to lose one from your dice pool, to shock, blood loss/instability, and even one shot-one kill effects).
10. A hit location system will be used (head, torso, 2 arms, 2 legs for bipeds).
11. Whole-body magic damage (fireball, etc.) will be half of what it currently is (e.g. a 6d6 fireball will now be 3d6).

Other than the obvious (completely changing the base mechanic), what issues does anyone see with implementing this system (my intent is that combat should be deadly and not entered into lightly).

I can provide an example of implementation after receiving initial feedback.

[BloodyManticore]

Why not just play shadowrun or steal their system. This just seems like it would wasre a lot of time with rules and complicate the game a lot more

[3catcircus]

BloodyManticore wrote:

Why not just play shadowrun or steal their system. This just seems like it would wasre a lot of time with rules and complicate the game a lot more

I specifically chose to not use Shadowrun for two reasons:

1. I don't have the Shadowrun books.
2. The Reflex System uses a d20 as opposed to a d6, so it is less complication rolling a pool of d20s and comparing the result to a TN (aka DC) than trying to convert to a d6 system.

An example of this system in play would be a bog-standard orc vs. a 1st level Fighter.

The orc would have the following stats (as relevant to this example):

base hp: 13
hit location hp thresh-holds: head 1, 7, 13, 20
torso 1, 13, 26, 39
limbs 1, 13, 20, 26
AC: 3, DR 2
Base to-hit TN: 18 (Str + Weapon Focus)
Base weapon stats (falchion): dmg 4, pen 1
dice pool for melee: 1d20
Initiative: 4 (1/2 Int)
Encumbrance Initiative Base: 12 (lightly encumbered)
Morale: 4 (1/2 Wis)

Using the NPC 1st-level fighter (Pirate/Buccaneer), his relevant stats would be:

base hp: 14
hit location hp thresh-holds: head 1, 7, 14, 21
torso 1, 14, 28, 42
limbs 1, 14, 21, 28
AC: 5, DR 1
Base to-hit TN: 16 (Str + Weapon Focus)
Base weapon stats (cutlass): dmg 3, pen 1
dice pool for melee: 1d20
Initiative: 5
Encumbrance Initiative Base: 12 (lightly encumbered)
Morale: 6

So - at the beginning of the round, each rolls initiative.

The orc rolls a 16 vs. his Init (failing), so his Init is 12 (just has Encumbranced Initiative Base). The NPC rolls a 3 (success), so his Init is 12 + 2 x his margin of success (5-3) = 16 - so the NPC can attack first.

Using his cutlass, he wildly flails at the orc. His DC is 16 - the orc's AC (3) = 13. He rolls an 11 (success). His damage = 3 + 2 (margin of success = 13 - 11) + 2 (Str bonus) = 7. The Orc's armor reduces this to 5 (DR 2 x pen 1). Hit location (1d6, 1d6) results in a hit to the upper abdomen. We see that his 5 points of damage to the torso exceeds the 1st wound threshold, so the orc will have a -1 dice pool penalty to all physical actions (meaning instead of 1d20, he has to roll 2 d20s and pick the highest instead of the lowest except for passive resistance checks).

The orc attempts a called attack to the NPC's head (-4 penalty), so his DC is 16 - 4 (called attack penalty) - 5 (NPC's AC) = 7. He rolls a 6 and a 3, succeeding. His damage is 4 + 2 (called attack) + 1 (due to having to pick the higher of the two rolls) + 3 (Str bonus) = 10, reduced by 1 (DR 1 x pen 1) = 9. Looking at the thresh-hold for the head, we see it exceeded the 2nd wound threshold, so the NPC has the following effects:

1. He has to roll a Con check. His DC is his CON score (15). He rolls an 8 (success) and does not go into shock.
2. He is at - 2 dice pool for all actions of any kind except passive resistance checks - instead of rolling 1d20, now he has to roll 3d20 but pick the highest of the rolls.

Round 2:

The NPC has to roll a Con check and gets an 11 - he passes and can act this round.

Each rolls initiative. The orc gets 4 and 14 (has to pick the highest) - so his Init is a 12. The NPC rolls 20, 16, 19 (has to pick the highest) and also goes on a 12, but after the orc since his result fails worse.

The orc rolls and gets 9, 11 and hits (18 - 5 = 13), hitting the NPC's right shoulder/upper arm, doing 8 points of damage - just enough to cause the NPC to have to roll 4d20H now when swinging his cutlass.

The NPC rolls 2, 6, 19, 6 and fails since he has to pick the highest of the 4 rolls.

Round 3: The NPC's Con check is an 18 - he fails due to shock - he is semi-conscious and can take no actions.

The Orc decides to press his attack, rolling a 5 and a 10. He gets lucky and hits the head/neck area. He does 9 points of damage. A second wound at the 2nd threshold which bumps it to the 3rd wound level. The NPC rolls a Con check and fails. Since he is already in shock, he immediately becomes unstable and becomes unconscious.

Round 4: The orc rifles through the now-unconscious NPC's pockets. The NPC's slight arm wound becomes a moderate arm wound and his serious head wound becomes a critical head wound.

Round 5: The orc gets a few silver pieces and a shiny ring off of the NPC. The NPC's critical head wound is now deadly as the two hits to his head/neck area have resulted in such grievous wounds that he bleeds to death.

[Tormsskull]

I think once you start to change the core mechanics of the system, you're better off just creating a new system from scratch. And that's not a bad thing.

My custom system in the works uses something similar to Target Numbers, but is based on the skill with the weapon or spell as opposed to just the attribute.

Whenever you're going to create a mechanic (or modify an existing one) be sure you know exactly what your purpose for doing so is. There's far too many mechanics in your example to be able to know how exactly they're all going to interact.

[Mythic Evil Lincoln]

You're clearly creative enough to start from scratch, I highly recommend it.

If I understand the intent of your rules, there's nothing in Pathfinder that's so mechanically wonderful that makes it worth hanging on to.

Take what you need from it, but present it as a complete, separate system. It will reveal more design flaws that way.

[3catcircus]

I'd like to keep some of the core to Pathfinder unless I can whole-sale implement a class-less system since a lot of the changes would be minor (i.e. core statistics like BAB turn into a number of dice in your pool rather than a bonus to-hit, Fort/Ref/Will mod becomes a number of dice in your pool rather than a bonus to saves, the Barbarian's rage will boost Str and Con just like always does - except now it ends up being more hp due to the fact that base hp = [10 + Str + 2 x Con] / 4, A Paladin with Cha 18 now gets to add an additional dice to the pool when smiting, etc.)

The Reflex System I am trying to adapt core mechanics from also uses a class-less life-path system, but uses 8 attributes instead of 6 (it includes the equivalent of Perception as an attribute called Awareness, and an Education attribute) - it is for a "modern real-world" as opposed to "medieval fantasy" game.

For example - the "Religion" occupation (requiring minimum attributes in their equivalent of Int, Wis, Cha) Provides 16 skill points to distribute (no more than 6 in any one skill) amongst Command, Instruction, Intimidate, Language, Medicine, Performance, Persuasion/Psychiatry, or to increase attributes at the rate of 4 skill points per 1 attribute point, as well as 6 personal skill points that can be spent on a bunch of other skills (or an attribute at a 5:1 ratio of skill points to attribute points).

I could easily see converting this for Clerics and stating that they can get 16 skill points to distribute amongst the class skills for clerics under Pathfinder and turning each spell school into a skill that you could add ranks to.

In any case - my intent (regardless of whether I go whole-hog or institute a minimally-invasive dice pool system) is that combat should be a lot more likely to end in the losing side being smart and running away (or just not killing everything they come across) unless they want combat to rapidly go from "its just a flesh wound" to an avalanche of shocky and bleeding-out combatants.

I think this also solves the wizard vs. house cat sample problem...

House Cat:

7 base hp
AC 4, DR 0
Base melee to-hit: 15 (Dex due to Weapon Finesse), dice pool 1d20
Base claw damage: -3, pen 1
Base bit damage: -2, pen 1

That's right - the cat has to have a significant margin of success in order to inflict significant enough damage

NPC Wizard (1st level):

12 base hp
AC 5, DR 2
Base melee to-hit: 10, dice pool 1d20
Base melee damage: 3, pen 1
Base ranged to-hit: 17, dice pool 1d20L
Base ranged damage: 3, pen 1