"Pool Party" (PoPa) is an exploration of a pool-based TTRPG mechanic that encourages more interaction between players and interesting choices.
- Combats are fast, easy to track, and dramatic, with variety by combatant type, including dangerous hordes and tricky boss battles.
- Encourage party interaction.
- Create action variety without analysis paralysis.
- Attack types matter and may be needed in combination.
- Scale combat in meaningful ways from single minor combatants to hordes and boss battles.
- Avoid buckets of dice. A fistful is good. Occasionally, an epic chain might top out at a dozen dice in a pool. Shadowrun (28+) is too much.
The base mechanic used in PoPa is a D6 dice pool. D6 pools formed from a combination of a base attribute, skills, and/or equipment will be familiar to many TTRPG players from games like Mutant Year Zero and Shadowrun.
Few, if any, of the individual mechanics are new, but they are combined in PoPa to create a different TTPRG action experience.
PoPa uses dice of different colors to represent different kinds of actions or effects. These might include physical, mental, magical, and diabolic, for example. Three to five colors is probably the right range for a system like this, especially if one type/color is more rare. This allows for multiple types of effects from a single pool.
PoPa assumes that multiple dice pools may be active at once and that they resolve either when a character declares an action to be the final one in a chain (see below) or at the end of the round in which the pool was created.
Many dice pool systems include ideas like requiring a number of successes when the pool is rolled and varying success numbers. PoPa goes one step further. Task difficulty is expressed in patterns. The base pattern is a single '5' on any die in the task color. A basic physical test might call for one Red 5+, for example. The key attribute of target patterns in PoPa is that each pattern must be satisfied from a single pool.
More complicated patterns are used to create unique challenges and to incentivize player cooperation in many instances. Patterns can require more successes than one player is likely to roll in an action or combinations of successes in different colors. Patterns can also simulate dramatic ideas, like the need to get a single high success to unlock other successes or to use lower success numbers to favor larger pools, even if tasks are relatively easy. Patterns can also mix types of dice to require more than a single effect to succeed and allow wildcard/any dice to be used for some successes.
- Simple Patterns
- Physical: 5, 5
- Mental: 6
- Magical: 4, 4, 4
- Varied Success Numbers
- Mental: 5, 4
- Magical: 6, 4, 4
- Physical: 5, 2, 2, 2
- Combining Types
- Physical: 5; Magical: 5
- Mental: 5; Magical: 6, 4, 4
- Magical: 5; any: 4
Spillover patterns are the key to combat and damage in PoPa, although they can be used to determine level of success for some other kinds of actions. In combat, some part of the target pattern is treated as a consistent threshold, representing concepts like armor and toughness. The character must first meet the threshold pattern. Then any other successes are applied as spillover successes, which may permanently reduce wounds or determine a level of success for an action.
Some opponents may have multiple thresholds patterns, to allow for different combinations of attacks to do damage and may have wounds that support any successes. Some may also have thresholds that use any successes. Thoughtful construction of target patterns for opponents can make any encounter more interesting.
PoPa supports using alternate polyhedral dice and or custome D6s with different numbers on them.
Pool manipulation in PoPa assumes some means of determining initiative, whether precomputed (e.g. Soulbound), rolled (e.g. D&D), action based (e.g. Doctor Who), or narrative initiative called out by the characters, with NPC initiative—when they can step in—serving as another way to differentiate between opponents. A narrative model with priority for chaining and combos over starting new pools would be interesting. In that way, players are encouraged to work together to beat some opponents before they can act.
When acting, characters can take actions that effect existing pools and/or start one or more new pools. There's a lot of narrative potential on top of these mechanics. Actions and abilities can have cool names and characters can describe how their combining or chaining actions to create new effects.
Melee Attack: The character forms a pool of dice for attacking with a sword.
Magical Melee Attack: The character forms a pool of dice for attacking with a sword.
Cast a Direct Spell: The character forms a pool of dice that is their magical ability plus dice described by the spell.
Cast a Combo Spell: The character manipulates a pool with magic dice in it, perhaps adding dice or converting dice types or sizes.
Throw a Teammate: One character creates a new pool by throwing their teammate who then immediately uses that pool as the base for further action.
Magical Lens: A character combines two pools with magic dice in them or "refracts" one or more existing pools into pools of the same types.
Fight the Horde: A character adds their own dice to a pool or starts a new pool, and then is able to resolve it against multiple target patterns at once.
Pool Alchemy: A character can use an action to adjust the results after the dice in a pool are rolled.
Ace Hero attacks a kobold, forming a pool of 2 strength + 1 sword skill -> 3 physical dice. The kobold has a defense patterns of Physical: 4 OR Magical: 2 and Wounds of Any: 3, so the characters always need one physical 4 to start wounding it, but after that a single 3 is enough to defeat it.
Ace Hero's player rolls 5, 3, and 2. The 5 clears the 4 toughness. The 3 spillover is enough to end the unlucky kobold.
Ace Hero attacks a ghoul, forming a pool of 2 strength + 1 sword skill -> 3 physical dice+ 1 magical die for their magical sword -> 3 physical dice and 1 magical die. The ghoul has a one defense pattern Magical: 2; Physical: 5 and wounds pattern of 2, 2, so the characters always need one magical 2 and one physical 5 to start wounding it, but after that physical 2s wound the ghoul.
Ace Hero's player rolls Physical 5, 3, and 1 and Magical 3. That's enough for one spillover for a single wound on the ghoul. The ghoul is now degraded in some way. Any new attacks on the ghoul must still clear the Magical: 2 and Physical: 5 successes to have a chance at spilling over another wound.
Ace Hero attacks a ghoul (see Magical Attack above), forming a pool of 2 strength + 1 sword skill -> 3 physical dice+ 1 magical die for their magical sword -> 3 physical dice and 1 magical die. Ace Hero's player rolls Physical 5, 3, and 1 and Magical 3. That's enough for one spillover for a single wound on the ghoul. The ghoul is now degraded in some way.
Bex Rogue steps in with a sneak attack, allowing them to chain their attack onto Ace's. Bex forms a pool using just their 2 stealth skill -> 2 physical dice, as described in their Sneack Attack action, but it will all be resolved as spillover damage. Bex's player rolls 4 and 3, easily finishing off the ghoul.
Carp Mageberry casts a fireball at a cockatrice, hoping that the physical component of the spell is more likely to get through the cockatrice's defenses, versus just magic alone. Being a powerful mage, Carp forms a pool of + 3 Magical dice for their Magic attribute and 1 Magical dice and 1 Physical dice for the fireball spell. Carp's player rolls 6, 4, 2, and 1 on the Magical dice and 5 on the Physical die, spilling over one Magical wound to the cockatrice.
Cockatrice Defense thresholds (read as OR between bullets)
- Magical: 6, 6
- Magical: 5; Physical: 4 Wounds
- Magical: 4, 4, 4
Carp Mageberry casts a fireball at a cockatrice (see above), hoping that the physical component of the spell is more likely to get through the cockatrice's defenses, versus just magic alone. Being a powerful mage, Carp forms a pool of + 3 Magical dice for their Magic attribute and 1 Magical dice and 1 Physical dice for the fireball spell. Carp does not resolve the action.
Bren Buffs-a-lot claims the next action to party in the pool, Channeling their own magical ability into Carp's fireball. Bren adds 2 Magical dice for their Magic attribute plus one for the Channel spell into the pool and then resolves it, hoping to defeat the cockatrice before it can act. Bren's player rolls 6, 5, 4, 4, 3, 2, and 1 on the Magical dice and 4 on the Physical die. The three spillover on the Magical dice are enough to remove the cockatrice from action.
Tan Titan picks up Brobarian and hurls them at a group of Froggos. Tan starts a pool with 3 Physical dice for their strength and 2 more for Brobarian's size. Brobarian claims initiative next and uses their Defeat the Hordes action to add their attack to an existing pool—this is a prerequisite of the action—and to then resolve the pool against multiple Froggos, instead of applying it to a single one. Brobarian adds 2 Physical dice for their strength and another 2 for their big axe. That's a whopping 9 Physical dice. Froggos have no target threshold, just a wound pattern, so any roll of four or over removes a Froggo from the group. We'd expect 5 Froggos to fall to Tan bowling with Bro.
Froggo Defense thresholds (some creatures have no defense) Wounds
- Any: 4
The remaining Froggos pile into Brobarian. They have the Horde* keyword, so any Froggos that can attack Brobarian, can combine their attacks into a single pool. 9 Froggos each add 2 Physical dice to the pool, for Body 1 and a small spear with 1 Physical attack die. That's 18 physical dice. Hordes must meet the target's threshold for each wound they score, but combining their attackes makes that possible.
Brobarian's physical defense is 5 for their armor, shield, and shield skill and 3 for their body. And Brobarian has 3 wounds that are the standard 4.
Defense thresholds
- Any: 5, 3 Wounds
- Any: 4, 4, 4
The GM role odds for the Froggos dice pool, three each of 1 to 6. Matching the patterns, the weight of the Froggos does just enough to bring down the Brobarian with 3 wounds.
- 6, 3, 4 -> 1 wound
- 6, 3, 4 -> 1 wound
- 6, 3, 4 -> 1 wound
- 5, ... (can't match the threshold pattern)
Enough small combatants can bring down the biggest fighters, without tedious rounds of missing attacks.
TODO: epic script of combo-ing to beat the threshold(s) a couple of times. Bosses could require different thresholds as they degrade, a la video game bosses changing modes as combats go on.
TODO: apply system to fixing something or riding a horse
TODO: multiple players working together to get through a non-combat obstacle in the game