Ships and Airships
There is nothing like the freedom of sailing the world on your own vessel with your trusted crew. These are rules to let own, upgrade and crew a ship. These rules apply to airships as much as water based ships; if a rule applies differently to an airship, it will be stated. These rules try to be as general as possible so that they can apply to any setting, any ship and any design you may desire.
Owning a Ship
The first step to being able to sail the world is getting hold of a ship in the first place. Purchasing a ship is a fairly simply affair, provided you have the coin, favours or bargaining power. However, there are more costs required to keep the ship is good condition.
Renting and Salvaging
You may only need a ship for a short time, in which case, you can rent a ship instead of buying one. The price for renting a ship for a week is 10% of its total cost however this does not necessarily include the cost of the crew members.
You may find a wrecked ship and want to salvage it and restore it to it's former glory. the cost to restore a ship depends on the state of the wreck. For example, if roughly half of the ship needs to be replaced or repaired, the cost of repairing the ship would be 50% of the total purchase price.
Repairs
You ship is likely to become damaged through combat, harsh weather and other means and so it needs to be repaired. While the ship is docked at a port, you may 1% of the ship's purchase price to increase a durability die by 1.
You may try to repair the ship while docked in a place without a port or facilities that can perform repairs. You may still try to repair the ship if the DM allows it, although it may cost more or require time spent finding materials and carrying out the repairs yourself.
Crew
Crew members are unskilled hirelings that are in your service; the cost for food, drink and other basic supplies is included in the cost for hiring them. Every ship type has a required number of crew members that are needed for it to operate properly, although you can have more crew members on the ship in case crew members are incapacitated.
If the number of crew members is below the required crew count but above half the required crew, the ship moves at half speed and can only fire one weapon as an action. If the number of crew members is below half of the required crew count, the ship is effectively unable to move.
Crew members can be incapacitated through disease or injury. At the end of a long rest, make a recovery check by rolling 1d20 for each incapacitated crew member. If the result is 14 or higher, the crew member is back to normal. If the result is 7 or lower, the crew member dies. Otherwise the crew member remains incapacitated and can make the check again the next day.
Roles
There are certain roles on a ship which allow a ship to run smoothly and effectively. There a necessary roles and optional roles; necessary roles need to be filled or the ship will not be able to function; optional roles can improve the operation of the ship. Roles can be filled by a PC or a skilled NPC hireling and one person can fill multiple roles if the DM believes that it is reasonable that they should be able to. A person filling a role counts towards the required crew count.
Necessary Roles
Pilot
Pilots the ship and orders crew to enable the ship to move. The pilot makes Wisdom (Sea Vehicles) checks to maneuver the ship to prevent damage or other effects during dangerous scenarios such as storms or landing. The ship cannot move of there is no pilot.
First Mate
A first mate's job is to keep the crew in line and ensure that order is maintained. They must make Charisma (Morale) ability checks (using the morale modifier of the ship) to keep crew under control and maintain order after a hard hits or during gruelling circumstances. If there is no first mate, the crew automatically fail at Charisma (Morale) checks.
Gunner
A gunner manages and orders the use of weapons, declaring when to fire and teaching the crew how to effectively use the weapons. They make attack rolls where the bonus to the roll is equal to the firepower of the ship + the gunner's proficiency in sea vehicles. If there is no gunner, no weapons can be used.
Optional Roles
Boatswain
A boatswain oversees the repairing of the ship and can keep it afloat in dire circumstances. They make checks to repair aspects of the ship (see the repair action). When the ship is being repaired at a dock, the boatswain can make an appropriate ability check to reduce the cost of repairs by half.
Surgeon
A surgeon looks after the health of the crew and prevents deaths at sea. They can make DC 15 Wisdom (Medicine) checks to aid an incapacitated crew member, with the crew member returning to normal on a success. Additionally at the end of a long rest, a surgeon can make a DC 15 Wisdom (Medicine) check to give all incapacitated crew members advantage on the recovery check.
Cook
A cook prepares food and drink for sailors to improve morale. At the end of a long rest, the cook may make a DC 15 Wisdom (Cook's Utensils) check. On a success, the morale modifier of the crew is increased by 2.
Sailing
The rules for travelling in chapter 8 of the PHB mostly apply the same way to sailing. Travelling for longer than 8 hours can cause exhaustion, the ship moves at half speed in difficult terrain, the ship can move at different paces with the corresponding effects, threats are detected in the same way and other activities can be done during travel. However, the ship can only move stealthily at a slow pace and is obscured by something such as fog, terrain or night. Additionally, marching order only applies when there are multiple ships moving together.
Travel Pace
Distance travelled in a hour with different ship speeds at different paces
| Ship Speed | Slow Pace | Medium Pace | Fast Pace |
|---|---|---|---|
| 30 ft. | 2 miles | 3 miles | 4 miles |
| 40 ft. | 3 miles | 4 miles | 6 miles |
| 60 ft. | 4 miles | 6 miles | 8 miles |
| 80 ft. | 6 miles | 8 miles | 10 miles |
| 100 ft. | 8 miles | 10 miles | 12 miles |
| 120 ft. | 9 miles | 12 miles | 15 miles |
Health and Damage
The state of the hull and propulsion of a ship is measured by a durability die (1d4, 1d6, 1d12, etc). When the ship is fully repaired, the durability die is at the maximum value. The hull and the propulsion have separate durability dice and ACs.
Whenever the hull or the propulsion take damage, the durability die is reduced. If the hull's durability is reduced to 0, the ship sinks and cannot be repaired. If the propulsion's durability die is reduced to half its maximum value, the ship moves at half speed. If it is reduced to 0, the ship cannot move at all.
Combat Rules
Initiative is rolled with the modifier equal to the pilot's dexterity modifier + their proficiency in sea vehicles.
On your turn, you may have the ship move up to it's speed, turn a up to 90 degrees and have the crew perform an action. Turning further than 90 degrees in one turn and other advanced maneuvers require a Wisdom (Sea Vehicles) ability check by the pilot.
Actions
Full speed: the crew focuses on moving quickly which doubles the movement speed of the ship until the start of your next turn.
Attack: you may use any number of weapons, making a separate roll for each. If you are below the required crew count, you may only fire one weapon.
Board: if the ships are within close range, your crew may use grappling hooks and planks to board the ship. The pilot must make a Dexterity (Sea Vehicles) check against the pilot of the other ship's own Dexterity (Sea Vehicles) check, winning ties. On a success, any number of people may move to the opponents ship.
Hunker down: The crew take defensive positions and try to keep the ship out of harm's way. Until the start of your next turn, attack rolls using grape shot and boarding checks against you have disadvantage.
Temporary Repair: If the ship has a boatswain, they can make a Wisdom (Carpenter's tools) check to repair the hull or a Wisdom (Weaver's Tool) to repair the propulsion. The DC for the check is equal to the AC of the hull or propulsion. On a success, the durability die is increased by 1. These repairs last until after combat has finished at which point the durability die returns to what it would have been without the repairs unless the durability die would be reduced to 0 without them, causing the durability die to be set to 1. Different tools may be need to repair different propulsion systems. Additionally if hull or propulsion is attempted to be repaired and is on fire, the fire is extinguished regardless of success.
Attacking
To use a weapon, the gunner chooses whether to make an attack against the hull or the propulsion. Then they make an attack roll using the firepower of the weapon and their proficiency with sea vehicles as the modifier. If the attack roll is equal to or higher than the target's AC, the target reduces it's durability die by 1 and any additional effects of the weapon are applied.
If the number rolled on the die is a 20, the attack is a critical hit. The first mate of attacked ship must make a Charisma (Morale) check. On a failure, the ship behaves as if it is below the required crew count until the end of it's next turn, as crew panic or recover from the impact.
Ranges are either short, medium or long. These are rough approximations as the distances in naval warfare are too large to be measured accurately. Short is boarding distance, up to about 30 metres or 100 feet away. Medium is between 30 metres and 100 meters or 100 feet and 300 feet. Long is between 100 meters and 200 meters or 300 feet and 650 feet.
A ship can move between short and medium range as part of the movement on its turn but has to take the full speed action to move between long and medium range unless your ship's speed is 80 ft. or greater.
Ship combat during a fight
If the party are in combat, they may still order the ship to perform actions and move as so long as there are people to crew the ship and the necessary roles. On a character's turn as an action, they can order the ship to take a course of action such as "Fire at will", "Retreat" or "Hold fire". The ship and crew will then take actions to fulfill this on the ship's initiative.
Weapons
Ballistas
| Name | Firepower | Range | Additional Effects | Cost |
|---|---|---|---|---|
| Ballista | +2 | Short | 200 gp | |
| Long range ballista | +2 | Medium | 300 gp | |
| Improved Ballista | +3 | Short | Critical hits are scored on a 19-20 | 350 gp |
Cannons
Once fired, cannons require one turn to reload. This can be done as part of the attack action
| Name | Firepower | Range | Additional Effects | Cost |
|---|---|---|---|---|
| Cannon | +4 | Medium | 400 gp | |
| Long Range Cannon | +3 | Long | 600 gp | |
| Large Calibre Cannon | +6 | Short | 600 gp | |
| Arcane Cannon | +5 | Medium | Does not need to be reloaded | 1000 gp |
| Charged Arcane Cannon | +6 | Short | Decrements the durability die by 2; if the attack roll is below 15, decrement the durability die of your own hull by 1 | 1200 gp |
Other Weapons
| Name | Firepower | Range | Additional Effects | Cost |
|---|---|---|---|---|
| Flamethrower | +3 | Short | On hit, does no damage to ship but decrement the durability die every turn until extinguished | 600 gp |
| Ram | +3 | Short | On hit, you may take the board action with advantage next turn | 500 gp |
Shot
| Name | Effect | Cost |
|---|---|---|
| Grape Shot | Can only be used to attack the hull; On hit, deal no damage but incapacitate a crew member plus one additional crew member for every 3 above the attack roll is above the hull AC. | 20 gp per round of shot |
| Incendiary Shot | On hit, does no damage to ship but decrements the durability die every turn until extinguished | 15 gp per round of shot |
Armour Upgrades
These can be applied to either the hull or the propulsion and act separately.
| Name | Effect | Cost |
|---|---|---|
| Reinforcing Boards | Increase AC by 1 | 200 gp |
| Metal Reinforcement | Increases AC by 2 and incendiary attacks have disadvantage | 500 gp |
| Metal Plating | Increase AC by 4, incendiary attacks have disadvantage and the ship's speed is reduced by 20 ft. | 750 gp |
Other Upgrades
| Name | Effect | Cost |
|---|---|---|
| Improved Rudder | You have advantage on Wisdom (Sea Vehicles) checks made to turn more than 90 degrees | 100 gp |
| Improved Propulsion | The ship's speed increases by 20 ft. | 400 gp |
| Arcane Propulsion | Your ship's speed is no longer halved by being below the required crew count but above half the required crew count | 500 gp |
Types of Ship
A ship is determined by it's speed, required crew, the AC and durability die of the hull and propulsion, the number of weapons it can hold and its cost. The cost of the ship doesn't include any weapons or other upgrades.
| Ship Type | Speed | Required Crew | Hull AC | Hull Die | Propulsion AC | Propulsion Die | Weapons Capacity | Cost |
|---|---|---|---|---|---|---|---|---|
| Cog | 40 ft. | 3 | 10 | 1d6 | 12 | 1d4 | 0 | 2,000 gp |
| Caravel | 100 ft. | 5 | 11 | 1d6 | 13 | 1d4 | 1 | 5,000 gp |
| Carrack | 60 ft. | 10 | 15 | 1d8 | 16 | 1d6 | 2 | 10,000 gp |
| Voyager | 80 ft. | 10 | 14 | 1d8 | 14 | 1d4 | 1 | 10,000 gp |
| Barge | 30 ft. | 20 | 16 | 1d12 | 17 | 1d8 | 2 | 15,000 gp |
| Galley | 40 ft. | 15 | 15 | 1d10 | 15 | 1d8 | 2 | 20,000 gp |
| Balinger | 100 ft. | 15 | 12 | 1d8 | 14 | 1d6 | 2 | 20,000 gp |
| Galleon | 60 ft. | 30 | 16 | 1d12 | 17 | 1d8 | 3 | 30,000 gp |
Design Thoughts
These rules originally started out as rules for airships before I quickly realised that they could just as easily be used for normal water-based ships. This explains the somewhat vague language like "propulsion" instead of "sails".
I wanted to make the ships simple enough to be usable but detailed enough for the ships to feel personal and precious so that people enjoy using them and owning them and so they're not forgotten.
Also things like the durability dice were inspired by Matt Colville's Strongholds and Followers and the way it handles the health of military units.