Notable System Changes

Skills:

There are some slight modifications to the available skills in One Piece 5e. Arcana has been changed to Artifact Knowledge and three new skills have been added Navigation (Intelligence), Culture (Intelligence), and Endurance (Constitution).

Culture (Intelligence):

Culture represents a character's understanding of various societies, traditions, and practices across the seas. A character proficient in Culture might understand local festivals, laws, or the significance of different symbols, all of which can be critical for diplomacy or gaining favor in unfamiliar lands.

Artifact Knowledge (Intelligence):

Artifact Knowledge is the study of ancient relics, powerful treasures, and the historical significance of lost technologies. This skill represents a character's ability to recognize and understand the origins, uses, and importance of artifacts found across the world.

Navigation (Intelligence): 

While Survival is frequently used to find your way on land and track creatures. Navigation is used to know the sea. It is the knowledge of Sea Charts, ocean patterns, and weather phenomenon. It is mainly used when traveling between islands or regions, but can also be used in situations like avoiding dangerous reefers.

Endurance (Constitution): 

Endurance is a measure of fortitude and the ability to well, endure. Many things that normally would have been a Con Save in the past (besides technique saves etc) are part of Endurance. Trying to outdrink some rowdy pirates? Hang onto an object for an extended period of time? Endurance is also used to maintain concentration on techniques when you take damage.

This makes the skills available as follows:

Acrobatics (DEX)

Animal Handling (WIS)

Artifact Knowledge (INT)

Athletics (STR)

Culture (INT)

Deception (CHA)

Endurance (CON)

History (INT)

Insight (WIS)

Intimidation (CHA)

Investigation (INT)

Medicine (WIS)

Nature (INT)

Navigation (INT)

Perception (WIS)

Performance (CHA)

Persuasion (CHA)

Sleight of Hand (DEX)

Stealth (DEX)

Survival (WIS)

Tools:

Many tool kits have been added or reworked for this system a more detailed explanation on each of their uses can be found in the Equipment section, but proficiency with a Tool is a requirement to use its associated tool kit. 

Here is a full list of available Tool Proficiencies along with their associated stats when making a check with them:

Armorsmith's Tools (STR or INT)

Alchemist’s Tools (WIS or INT)

Botanist's Tools (DEX or INT)

Cartographer's Tools (WIS or INT)

Chef's Tools (WIS or DEX)

Disguise Tools(Disguise Kit) (DEX or CHA)

Angler's Tools (STR or DEX)

Lock Picking Tools(Lock Picking Kit) (DEX)

Medical Tool(Medicine Kit)(WIS or INT)

Poisoner's Tools (WIS or INT)

Carpenter's Tools(Ship Wrights) (STR or INT)

Weaver's Tools (DEX or INT)

Weaponsmith's Tools (STR or INT)

Vehicles:

One main vehicle type stands out in the world of One Piece, ships, but there are a few others as well. 

A full list of available Vehicle Proficiencies:

Ships

Submersibles

Wavers

Ground Vehicles

Airships

Mounted Weapons

Short Rests

A short rest is a period of downtime, at least 1 hour long, during which a character does nothing more strenuous than eating, drinking, reading, and tending to wounds. A character can spend one or more Hit & Energy dice at the end of a short rest, up to half the character’s maximum number of Hit and/or Energy Dice. For each Hit Die spent in this way, the player rolls the die and adds the character’s Constitution modifier to it. For each Energy Die spent in this way, the player rolls the die and adds the character's Constitution modifier to it. The character regains hit points and/or Energy points equal to the total. The player can decide to spend an additional Hit or Energy Die after each roll. A character regains some spent Hit and Energy Dice upon finishing a long or full rest, as explained below.

Long Rests

A long rest is a longer period of downtime, at least 8 hours long, during which a character sleeps or performs light activity: reading, talking, eating, or standing watch for no more than 2 hours. If the rest is interrupted by a period of strenuous activity-at least 1 hour of walking, fighting, using a Technique, or similar adventuring activity- the characters must begin the rest again to gain any benefit from it. At the end of a long rest, a character regains half of their Maximum hit and energy points. The character also regains half of their spent Hit and Energy Dice. For example, if a character has eight hit & energy Dice, he or she can regain four spent Hit and energy Dice upon finishing a long rest. This does not Heal Conditions that may last into the Long Rest. Characters cannot gain the benefit of a long rest if they are diseased. A character can’t benefit from more than one long rest in a 24-hour period, and a character must have at least 1 hit point at the start of the rest to gain its benefits.

Full Rests

A full rest is a period of extended downtime, at least 24 hours long, during which a character sleeps or performs light activity: reading, talking, eating, or standing watch for no more than 8-12 hours. If the rest is interrupted by a period of strenuous activity-at least 1 hour of walking, fighting, using a technique, or similar adventuring activity- the characters must begin the rest again to gain any benefit from it. At the end of a full rest, a character regains their Maximum hit and energy points. The character also regains all of their spent Hit and Energy Dice. This Heals Conditions that may last into the full Rest, such as the Diseased condition. A character can’t benefit from more than one full rest in a 96-hour period, and a character must have at least 1 hit point at the start of the rest to gain its benefits.

WILL OF D

Will of D is a rule the game master can use to reward you for playing your character in a way that’s true to his or her personality traits, ideal, bond, and flaws. By using the Will of D, you can draw on your personality trait of compassion for the downtrodden to give you an edge in negotiating with the Beggar Prince. Or inspiration can let you call on your bond to the defense of your home village to push past the effect of a power that has been laid on you.

GAINING THE WILL OF D

All players begin any mission they undertake with a Will of D. They can also give you the Will of D for a variety of reasons. Typically, GMs award it when you play out your Ambitions, Drive, Goals or Fears and otherwise portray your character in a compelling way. Alternatively, you gain a Will of D when you roll a Natural 20 on an ability or skill Check (that are not a part of a class or race feature) or Saving throw. A player can have up to 3 Will of D at any given time and they reset at the end of a mission.

USING THE WILL OF D

If you have the Will of D, you can expend it for the following:

• Advantage or +5 on an attack roll.

• Advantage or +5 on a saving throw.

• Advantage or +5 on an ability or skill check.

• To slightly alter the scene to your benefit.

• Gain an immediate Reaction, even with an ability or technique that is an action.

• Gain immediate insight or clue into the current situation or mystery.

• Automatically succeed a Death saving throw.

Additionally, if you have a Will of D, you can reward another player for good roleplaying, clever thinking, or simply doing something exciting in the game by transferring your Will of D to them, for them to use.

Curse of Hatred

Sometimes, the Will of D is snuffed out by tragedy and darkness. However, from the ashes of the Will of D, a different flame arises. The Flames of Hatred.

Using the Curse of Hatred

If you have Curse of Hatred, you can expend it for the following:

Grant the enemy disadvantage or -5 on an attack roll.

Grant the enemy disadvantage or -5 on a saving throw.

Grant the enemy disadvantage or -5 on an ability check.

Grant the enemy vulnerability to your damage.

Mark an enemy. For the next minute, you gain a bonus to attack and damage rolls against that single enemy equal to half your proficiency modifier. Furthermore, all your DCs against that enemy increase by 1/3 your proficiency modifier.

Critical Limits

The critical limit for attack rolls is 16, unless a subclass ability states otherwise. Any reduction to the critical range beyond this limit (e.g., reducing it to 15, 14, or lower) is considered excess and does not further extend your critical range. If an ability eliminates critical range entirely, the excess is removed starting from the highest critical number.

Overcoming AC for Critical Hits

Critical hits require precision and power. Even if your critical range is extended (e.g., 19 or lower), you must first overcome the target's AC to confirm the critical hit. If your attack roll does not meet or exceed the AC, the attack does not land, and the critical is negated. A natural 20 is the only automatic success for landing an attack. If you cannot score a critical hit on a 20 due to specific restrictions, it is not considered an automatic critical.

Critical Hits: Maximize, Then Roll

When a critical hit is confirmed, the damage is calculated as follows:

Roll your damage dice as normal.

Add the maximum possible value of the damage dice as a bonus.

For example, if you score a critical hit with a weapon that deals 1d6 damage and has a +4 modifier, the total damage would be:

1d6 + 4 (rolled normally) + 6 (maximum of the damage die).

Additional Damage for Extended Critical Ranges

If your critical range exceeds the limit of 16 (e.g., 15, 14, 13, etc.), you gain additional damage dice when scoring a critical hit. For each number beyond 16 in your critical range, add one extra damage die to the critical damage calculation.

EX.

If your critical range is extended to 15 and you roll a critical hit, you gain one additional damage die.

If your critical range is extended to 14, you gain two additional damage dice, and so on.

This rule incentivizes powerful builds that extend critical ranges, ensuring your precision is rewarded with explosive damage.

Fire Affinity: Burn

The target suffers lingering flames, taking damage over time and suffering from impaired actions due to the heat.

Fire can also cause Scorched, leaving severe marks that weaken the target’s resilience.

Cold Affinity: Chilled or Frozen

The target is slowed and weakened by the icy cold, with Frozen rendering them immobilized under ice.

Lightning Affinity: Shocked , Electrocuted

The target is struck with electrical energy, disrupting their reactions and coordination.

Poison Affinity: Poisoned , Envenomed 

The target is afflicted with toxins, weakening their body and causing ongoing damage.

Acid Affinity: Corroded or Melted

The target’s defenses degrade as armor and flesh are dissolved, leaving them vulnerable to attacks.

Necrotic Affinity: Decayed or Rotted

The target’s vitality is drained, with flesh wasting away and their overall health deteriorating.

Radiant Affinity: Dazzled  or Burned

The target is overwhelmed by intense light, impairing their vision and focus.

Radiant can also cause Scorched, leaving severe marks that weaken the target’s resilience.

Psychic Affinity: Confused,  Berserk, Charmed, Concussed, Fear, Slowed

The target’s mind is scrambled, impairing decision-making and leaving them vulnerable to mental attacks.

Thunder Affinity: Deafened

The target’s hearing is disrupted, disorienting them and hindering their perception.

Wind Affinity: Bleeding, Lacerated 

The target suffers deep, slicing wounds as wind energy tears through their body.

Earth Affinity: Bruised, Staggered, Dazed, Stunned

The target suffers heavy, blunt damage, leaving them battered and slowed.

Weight Categories

Light (0-10 lbs): Small items like basic weapons, tools, and personal belongings.

Medium (10-50 lbs): Heavier weapons, gear, and moderate-sized cargo.

Heavy (50-200 lbs): Large equipment, treasure chests, or heavy crates.

Very Heavy (200+ lbs): Extremely large objects, ship parts, or boulders.

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Carrying Capacity Rules

Base Carrying Capacity: 

A character can carry weight in pounds equal to 15 x Strength score.

Example: A character with 14 Strength can carry up to 210 lbs.

Encumbrance Penalties:

Light Load (0-50% capacity): No penalty.

Medium Load (51-100% capacity): -10 ft speed, disadvantage on Stealth checks.

Heavy Load (101-150% capacity): -20 ft speed, disadvantage on Stealth, Acrobatics, and Athletics checks.

Overburdened (151%+ capacity): Cannot move or perform agile actions.

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Special Rules for Devil Fruit Users

Zoan Users:

Hybrid or animal form increases carrying capacity by 50%.

Advantage on lifting or moving checks.

Logia & Paramecia Users:

No changes unless specific abilities affect lifting.

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Group & Ship Weight Limits

Group Capacity: Total weight is the sum of all individual capacities.

Ship Capacity:

Small Ship (Sloop): 5,000 lbs capacity.

Medium Ship (Frigate): 10,000 lbs capacity.

Large Ship (Galleon): 20,000 lbs capacity.

Exceeding cargo limits halves the ship's speed and imposes disadvantage on Maneuvering checks.

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Equipment Weights

Weapons:

Light weapons: 1-5 lbs

Heavy weapons: 6-20 lbs

Armor:

Light armor: 5-10 lbs

Medium armor: 11-25 lbs

Heavy armor: 26-50 lbs

General Goods:

Backpack: 5 lbs

Rope (50 feet): 10 lbs

Treasure Chest (full): 100 lbs

Power Scaling

The ranking system determines what your character is ready for at each level:

Blues: Levels 1 to 4

Paradise: Levels  5 to 9

Ocean Floor: Levels 10 to 12

New World: Levels 13 to 16

Laugh Tale: Levels 17 to 20

Every mission will have a level cap determined by the GM upon mission posting.

You will not earn the title for the region until the first time you get there, e.g., Paradiser, Ocean Dweller, New Worlder, and Laugh Tale.

Core mechanics such as critical and items like Raw Metals may change in the future.

Even though the level cap is high, there are advantages to staying at a lower level and really working out your character, such as:

Gaining more experience with your abilities.

Mastering specific skills and techniques.

Building stronger relationships with other characters.

Exploring the world at a manageable pace.

Damage Reduction (DR):

Damage Reduction is a form of damage mitigation that applies to specific types of damage, such as physical damage from slashing, piercing, or bludgeoning attacks. DR reduces the amount of damage taken from those particular sources. For example, a character with DR 5/slashing would reduce the damage taken from slashing attacks by 5 points, but DR might not apply to other types of damage like bludgeoning or piercing.

Universal Damage Reduction (UDR):

Universal Damage Reduction is a broader form of protection that applies to all types of damage, whether from slashing, bludgeoning, piercing, or other physical sources. Nothing bypasses Universal DR unless it specifically states that it does, making it a more versatile and powerful form of damage mitigation compared to regular DR.

In summary, DR applies only to certain damage types, while UDR applies to all damage types and cannot be bypassed unless explicitly stated.

Force Damage and its Effects on Defenses

In the system, force damage represents a concentrated manifestation of raw power, capable of piercing through most forms of defense. This unique damage type is designed to overcome both temporary hit points and standard forms of Damage Reduction (DR). However, it does not bypass Universal Damage Reduction (Universal DR), which remains the highest form of defense.

Interactions with Temporary Hit Points:

Overcoming Temporary Hit Points: When force damage is dealt to a target, it bypasses any temporary hit points the target might have. This means that the damage is applied directly to the target's actual hit points, ignoring any buffer that temporary hit points might provide. This makes force damage particularly effective against opponents relying on temporary defenses.

Interactions with Normal Damage Reduction:

Bypassing Normal DR: Force damage completely ignores normal Damage Reduction (DR). Whether the DR is based on physical resilience, elemental affinity, or other standard forms of protection, force damage cuts through these defenses, dealing its full damage directly to the target's hit points.

Interactions with Universal Damage Reduction:

Respecting Universal DR: Despite its potency, force damage does not bypass Universal Damage Reduction. Universal DR represents the pinnacle of defense, an impenetrable barrier that even the most potent attacks must contend with. When force damage is applied to a target with Universal DR, the DR is calculated as normal, reducing the damage accordingly.

Occasionally, a character's journey traverses multiple classes, and this is where multiclassing plays a vital role. These prerequisites outline the minimum statistics required for multiclassing into or back into any class within the system. Please be aware that the path of the Haki Master includes a specific feat requirement, designed to prevent early or unearned access to this class.

Meeting the level requirement is just the beginning; you must submit your character for evaluation. Your character sheet should reflect the dedicated effort you've invested in adhering to these guidelines. Remember, multiclassing is a optional rule and not an automatic entitlement.

Class Requirements:

Brawler: 16 STR or DEX, 14 CON

Craftsman: 16 INT, 14 CON 

Doctor: 16 INT or WIS, 14 in the other

Haki Master: 16 INT or WIS, 14 CON or CHA, 15 STR or DEX, Armament or Observation Attunement, depending on your chosen subclass

Leader: 16 CHA, 14 INT

Marksman: 16 DEX, 14 WIS or CHA

Thief: 16 DEX, 14 INT or CHA

Weapon Wielder: 16 STR or DEX, 14 CON

Monster: 16 STR, 14 CON

Scholar: 16 INT, 14 DEX

Maestro: 16 CHA, 14 CON

Rage Bearer: 16 CON, 14 STR

Primalist: 16 WIS, 14 STR

(Note: There are no Proficiencies Gained from Multiclassing and techniques known total is added together. Max Technique rank known is also decided by class level. For example a level 2 Maestro/Level 3 Primalist would only have access to blues techniques.)

There are powerful artifacts, Devil Fruits, and other supernatural forces that grant extraordinary abilities. The system uses 3 Soul Slots, and each one can be filled with an item, power, or ability that grants the creature a significant advantage.

Attunement Rules:

Maximum Slots: Every creature can attune to a maximum of 3 Soul Slots unless otherwise stated.

Soul Slot Types: These slots represent powerful abilities or items. Examples include Devil Fruits, Devil Fruit Weapons, Powerful Artifacts, or Cursed weapons.

Attunement: Characters can attune to a Soul Slot in various ways, during a long rest, spending time with the object, Eating a Devil Fruit or training the power (POI). not everything attunes right away but in certain instances such as eating a devil fruit, your character instantly attunes the abilities of the fruit to their soul.

Slot Restrictions: A creature cannot attune to the same type of item (e.g., two Devil Fruits or two artifacts) unless otherwise stated.

Soul Slot Benefits: When attuned, a creature gains the abilities or benefits of the item/power in that slot. The more powerful the item or power, the more taxing it may be to manage. (E.g costs more than one slot)