Ship to Ship Combat

Ship to Ship combat will follow nearly all the rules in the Skulls and Shackles Player’s guide, with exceptions as follows. These changes are due to much testing from various DM’s, and my own theorycrafting. More rules may be added as we delve deeper into ship to ship combat play.

Ship Roles

There are 5 main roles aboard the ship that the PC’s can take part in, listed below. Each role has specific tasks that they can perform. The Captain does not have specific actions, but they can choose any action that has (Captain) in the title.


Much as in the basic rules, the pilot’s initiative determines when that ship acts. The pilot rolls against all other pilots in the combat to determine who has the Upper Hand each round. The upper hand bonus works exactly the same (1 square of reposition per 5 beaten, or 90 degrees of turn per 5 beaten.)

Pilot Actions:

Tack or Jibe: The pilot turns the ship or moves diagonally forward on the battlemat. Make a Profession (sailor) check DC10 with the following difficulty modifiers:

Current Speed
0xAcceleration = +0
2xAcceleration = +5
3xAcceleration = +10
4xAcceleration = +15

Diagonally Forward = +5
Hard to Port/Starboard (90 degree turn) = +10

For example a pilot on a ship moving twice it’s acceleration trying to execute a 90degree turn to Port would need to succeed on a DC25 Profession (sailor) check. This will be the action pilots will need to take every round they want to do anything but move the ship straight forward. When the ship is just moving straight forward the pilot may do these other actions.

Evasive Maneuvers: The pilot makes an opposed Profession (Sailor) check against the other pilots in the combat. A success grants the ship a +4 to its AC and saves for the next round, but a -8 to the Master at Arms for any siege weapon attacks. For each 5 that the pilot beats her highest opponent she may increase this bonus by +2.

Make Way: The pilot makes an opposed Profession (sailor) check against the other pilots in the combats. Success allows them one of the following effects:

Chosen Enemy Pilot is -4 on Profession (Sailor) checks for a round
Chosen Enemy Ship is -4 on AC and saves for a round
Chosen Enemy Siege Gunners are -4 on attacks for a round

Full Ahead/Heave To (Captain): The Pilot is in charge of determining the speed of the vessel by ordering the crew to lay on more sail or draw the sails in. This changes the ship’s speed by its acceleration up or down a step not exceeding maximum speed. It requires a sailing check with the same modifiers listed in the Tack or Jibe action.


This role is for someone on the deck of the ship shouting orders to the crew, relaying info from the lookout to the pilot and so on. Imagine them standing in the bow or on the sterncastle with a spyglass.

Bosun Actions:

Look Alive (Captain): the Bosun drives the crew to pay close attention to their jobs making the ship sail smoothly and well. With a successful DC10 Profession (sailor) check you grant the Pilot a +2 on Profession (sailor) checks to pilot the ship. This is basically an Aid Another, a good default for when the other actions don’t apply.

Take Cover: the Bosun orders the crew protect themselves from incoming siege weapon fire, magical attacks, or to brace for the impact of a ram etc… the Pilot receives a -4 penalty to Profession (sailor) checks to pilot the ship, and the Master at Arms receives -4 to attacks with siege weapons, but the crew gets +8 cover bonus to AC and +4 to reflex saves (replacing their normal cover bonuses as occupants of a ship).

Fix It: the Bosun uses this command whenever there is a mishap or problem on the ship either due to siege weapon damage or any other reason: a spar breaks, a sail flies loose, something catches fire, a siege engine misfires etc… This gives the Pilot and Master at Arms the same penalties as “Take Cover”, but with a successful Craft (ships) check (DC 15 + Toughness Lost) the problem can be jury-rigged sufficiently to remove any penalties or prevent further damage. This is also used to allow the ship a reflex save to put out a fire from one section of the ship.

Grapple (Captain): the Bosun calls for the grapple when the time comes. This gives the Pilot and the Master at Arms the same penalties as “Take Cover”, and then the person calling the command makes a combat maneuver check using the base CMB of the ship plus their Profession (sailor) modifier as the total CMB of the grappling maneuver against the CMD of the target ship. This command can also be used to break a grapple in the same way, but with a -4 penalty.


A role for a bard or First Mate. This person is leading the crew in songs, or cheering them on, and generally trying to raise their morale. They should be someone with a high Charisma since they will mainly use Diplomacy, Intimidate, or Perform.

Shantyman Actions:

Boost Morale (Captain): the Shantyman makes a Diplomacy or Perform check DC 15 + 2x(current Morale +1). See how to calculate Morale in Boarding Rules below. A success raises the Morale of the crew by 1 for the remainder of the encounter. Alternately Intimidate can be used in place of Diplomacy or Perform, but after the encounter the crew’s Morale drops by an additional 1. This caps at double the starting Morale of the crew.

Mock Enemies (Captain): the Shantyman can make an Intimidate of Perform check DC 15 + 2x(enemy’s current morale) to lower the Morale of an enemy crew by 1 for the remainder of the encounter. Alternately Diplomacy can be used if the Shantyman offers bribes (which must be given in the event of victory). This cannot be used to lower Morale below 0.

Sea Chanty: the Shantyman can sing songs which aid timing and cooperation among the crew resulting in +2 to all other roles in any of their skill checks.

Bloodthirsty Ballad: the Shantyman can get the crew riled up for battle with a successful Perform check DC 15 + 2x (enemy’s current morale), providing a +1 bonus to their attack and defense stats. This bonus caps at +5.

Master at Arms

Or Master Gunner, or Siege Engineer etc… This is a role for the person in charge of the all the siege engines on a ship. They typically do not actually fire the weapons (they have crew for that), but they rely on the Profession (siege engineer) skill to be successful.

Master at Arms Actions:

Load/Aim/Fire (Captain): the basic job of the Master at Arms is to decide where and when to fire all the weapons on the ship, and at what. For the most part this just involves following the rules of Siege Engines as in the Skull & Shackles Guide and below. How many crew are on each engine? How many rounds does it take to load, to aim etc…? The Master at Arms can coach all the weapon crews simultaneously assuming there are enough crew to man each weapon. The Master at Arms then rolls a Profession (siege engineer) or Knowledge (Engineer) check DC10 to give each weapon crew a +2 bonus on their attack (as Aid Another). You can increase the bonus granted by 2 for each 5 points you exceed DC10.

Calculate a basic crew’s attack with the following modifiers:
Untrained with Siege Weapon = -4
Range increments = -2 per increment beyond first
Pilot’s “Evasive Maneuvers” Action = -8
Enemy Pilot’s “Make Way” Action = -4
Bosun’s “Take Cover”, “Fix It”, or “Grapple” Actions = -4
Direct Fire Only:
Base Attack = +2

Indirect Fire Only:
Knowledge (Engineer) = +0
No line of sight (Indirect Fire Only) = -6
Successive Shots = +2 (Max 10), Half if no line of sight
Successive Shots after a hit = +10

Steady…Steady: The Master at Arms may spend an extra round coaching her weapon crews on their aim. With a successful Profession (siege engineer) or Knowledge (Engineer), adding his base attack opposed by the Sailing Check of the Pilot, the Master at Arms may have a siege weapon that fires in that next round deal +1 damage per damage dice on it’s roll.

Make Her Bleed: The Master at Arms has his crews target a part of the ship that they previously damaged and may make a Profession (siege engineer) or Knowledge (Engineer) adding his base attack opposed by the Sailing Check of the Pilot to have each siege weapon that fires in that round deal +1 damage per damage dice on it’s roll. This stacks with “Steady…Steady” so it is possible to deal up to +2 damage per dice against structures with an extra round of aiming and two successful Profession (siege engineer) checks against a previously damaged part of an enemy ship.

Ship Damage and Hit Points

When in Ship to Ship Combat Ships will use a Damage Roll vs Toughness DC mechanic.
The Toughness DC for a section of the ship is equal to 5 + Hardness + 1 for every 100 HP the part has (round down).

For example: A Galley has Hp of 1,560 hp, its oars have 1,400 hp, and its sails have 320 hp. It has a hardness of 5.

  • The DC for Each section of the hull is therefore 5 (Base) + 5 (hardness) +15 (1,560/100 rounding down) = 25
  • The DC for each side of the Oars is 5 (Base) + 5 (Hardness) + 14 (1,400/100 round down) = 24
  • The DC for each section of the Sails is 5 (base) + 3 (320/100 round down) = 8

Determining The Damage Roll

The Damage Roll is determined by the dice used in either the Siege Weapon, Spell or Ramming attack. For each dice used in an attack add a bonus to your Damage Roll.

d4 = +0.5
d6 = +1
d8 = +2
d10 = +3
d12 = +4

Bonuses gained from feats, class features, special abilities, magical enchantments or special ammunition get added as normal.

This can also be used to determine spell-damage. A fireball dealing 10d6 damage for example has a damage bonus of +10, a 5th level burning hands has a damage bonus of +2 (5 × 0.5) (always round down). Static Bonuses from spells add 1 to the damage roll per 3 points of additional damage.

  • Fail to beat Toughness DC: You deal a glancing blow, your shot, cannonfire or spell does only superficial damage not effecting the performance in any meaningful way.
  • Beat Toughness DC: The section is damaged, reducing the Toughness DC by 1.
  • Beat Toughness DC by 5: The section is dashed, reducing the Toughness DC by another 1.
  • Beat Toughness DC by 10: The section is broken.
  • Beat Toughness DC by 15: The section is destroyed.

These effects are cumulative. i.e. beating the toughness by 10 will result in the Broken conditions, and reduce the toughness by 2.

Ships of Gargantuan or larger size have 4 hull areas: Bow, Stern, Port, and Starboard. Any single area that receives the broken condition gives a -2 penalty to it’s AC, CMB, CMD, and Profession (sailor) checks to pilot the ship. Any area reduced to 0 is taking on water and the ship’s maximum speed is halved. Any two areas reduced to 0 means the ship is sinking.

Ships of Gargantuan or larger size have 1 sail area per 30 feet of sailing speed: Any single sail area that receives the broken condition gives a -4 to Profession (sailor) checks to pilot the ship. Any area reduced to 0 is reduces the ship’s maximum sailing speed by 30 until repaired.

Ships of Gargantuan or larger size have 2 oar areas if capable of rowing speed: Any single oar area that receives the broken condition gives a -4 to Profession (sailor) checks to pilot the ship. Any area reduced to 0 is reduces the ship’s maximum rowing speed by half until repaired. A successful shearing action destroys that section of oars.

A ship has arcs of fire that correspond to each “area” of the ship. A siege weapon may only hit targets within the arc of fire of that part of the ship. When attacking a ship with a siege engine you may choose Sails, Oars, or one section of Hull you have line of sight to. Indirect fire weapons like catapults may target any section of a ship within its arc of fire. Spells may target more than one area if they are sufficiently large.

A sinking ship cannot move or attack, and it sinks completely after 10 rounds of gaining the Sinking condition. Each additional hit that beats the ship’s Toughness DC reduces the remaining time for it to sink by 1 round. A ship that sinks completely drops to the bottom of the body of water and is considered destroyed. A destroyed ship generally can not be repaired without powerful magic – it is so significantly damaged it cannot even be used for scrap material. Generally non-magical repairs take too long to save a ship from sinking once it begins to go down.

Siege Engine Rules:

Indirect Fire Weapons: Ships receive reflex saves against indirect fire weapons, with the DC equal to the total knowledge (Engineering) check. Successful saves halve the damage bonus on the damage roll.

Scoring a Critical Hit: If you roll a Critical Hit on your Attack Roll with a Siege Weapon that Weapon gains a +5 bonus to its Damage score.

Firing Broadsides: Broadsides can only be fired within the first range increment of the siege weapon. Rather than creating absurdly high damage numbers firing Broadsides adds 2 to the Damage bonus for each similar siege weapon used. Firing 3 cannons for example grants a +10 damage bonus (6 base, and then +2 for each additional cannon after the first).


When an area of the ship takes fire damage (such as from Alchemist’s fire, flaming arrows, certain spells, and other effects at the GM’s discretion), it must immediately make a Fortitude save (DC 10 + damage dealt) or catch fire.

Once an area has caught fire, it automatically takes an attack at +2 damage at the start of it’s round (ignoring hardness) as the fire spreads. This damage roll increases by 1 for each round that passes. Using the Bosun’s “Fix It” action allows the ship to make a Reflex save (DC 15 + the number of rounds the ship has been on fire). A successful saving throw means the fire has been put out in that section of the ship.

Repairs and Magic

Ships toughness can be repaired at a rate of 1 toughness per 100HP. A piece of the ship keeps the “Broken” condition until it is fully repaired. A piece of the ship keeps the “Destroyed” condition until it is completely replaced or rebuilt; a process that requires the ship to be docked and the full price paid for the section of the ship (1gp per HP of the section), or some seriously powerful magic.

Magic can repair a sinking ship with a DC 20 check (using the same bonus dice as damage), with a penalty equal to the amount of Toughness the ship’s hull has lost (totaling all 4 sections). The more damage a ship has received the harder it is for an emergency magical repair. Spells do not repair any toughness if used in this way, but can bring a piece of the hull back to the “Broken” condition for purposes of sinking. The section of the ship is still treated as destroyed for future repairs.

Make Whole can be used as a full round action (instead of it’s usual 10 minute cast time) to attempt to stop a ship from sinking using the rules above.

Boarding Action Rules:

A crew has three stats: Attack, Defense & Morale.

Attack is equal to the captain’s Profession (sailor) skill.

Defense is equal to the captain’s Profession (sailor) skill + 10.

The following modifiers apply to both Attack and Defense:

  • Every 5 crew below minimum = -1
  • Every 10 crew over minimum = +1
  • Masterwork Arms = +1
  • Won previous round(s) = +2(cumulative)
  • Lost previous rounds(s) = -2(cumulative)

Morale a crew’s starting Morale score is equal to their side’s Infamy score divided by 10(round down), with a minimum Morale score of 1 and a maximum score of 10. Morale can be modified by the Shantyman prior to boarding, or by purchasing the “Well Paid” upgrade below, or by circumstantial bonuses or penalties the GM applies.

Once starting Morale has been determined the attacking crew rolls a D20 + Attack and compares it with the defending crew’s Defense stat. Whichever side is higher deals 1 point of Morale damage to the other side. The victor of that round has a +2 to attacks and defense in the next round (cumulative). Keep track of the total amount of Morale Damage each side receives during the Boarding Action. This continues till one crew reaches 0 Morale.

A crew that reaches 0 Morale stops fighting and either surrenders or retreats to their own ship or tries to escape. This ends the Boarding Action. The victorious side receives an immediate +1 to their Morale.

Roll 1d4 per point of Morale Damage each side received during the Boarding Action. This represents the number of fatalities that side suffered. For example if a crew started with 4 Morale and was defeated, then roll 4d4 to determine the number of deaths they suffered. If a crew started with 4 Morale and was victorious ending with 2 Morale, they still suffered 2d4 fatalities during the Boarding Action. Casualties (serious non-fatal injuries) are always double the number of fatalities.

Disregard any obviously ridiculous results such as a crew suffering more fatalities and casualties than they have members of their crew.

Ultimately, the success or failure of the battle will be determined by the “Officer’s Battle” using the PC’s. But with this system it is possible for the PC’s to win the battle, but for their crew to have been routed (or vice versa). In this case, have the losing crew come storming back when they see the success of their officers. The battle is won, but with a heavy cost.

Crew Upgrades:

Each of these upgrades can be purchased for a ship once unless otherwise specified. Once purchased, the upgrades are permanent for the ship and do not transfer to another ship unless the entire crew moves as well.

Got Your Back: this upgrade represents a crew that looks out for each other in combat (or a skilled surgeon), resulting in 1d4 fewer casualties per combat. 2,500gp

Landlubbers Need Not Apply: this upgrade represents a crew of more highly skilled sailors than normal providing a +1 on any of the Pilot’s or Captain’s skill checks. 1,000gp

Masterwork Arms: this upgrade grants +1 to the crew’s Attack & Defense stats. 10,000gp

Siege Weapon Training: this upgrade removes the -4 penalty crew normally has for operating siege weapons. 1,000gp per weapon type

Vicious Fighters: this upgrade represents a crew that fights in a particularly bloodthirsty manner dealing 1 extra damage to their enemy’s morale per successful round in a Boarding Action. 10,000gp

Well Paid: this upgrade gives a +1 to the crew’s Morale stat. This upgrade can be purchased multiple times. 10,000gp

Ship to Ship Combat

Sinking Ships Cidwin Cidwin