Ship Combat

Homebrew Mechanics for Epic Ship Battles in D&D 5e

*Indicates a reference to another homebrewed mechanic not included in this document,

Initiative
Refer to the *Travel Pace in the stat block of each ship involved in combat. The ship(s)
with faster Travel Pace take their turn in initiative before ships with a slower Travel
Pace. If two or more ships have an equal Travel Pace, roll for initiative normally, adding
each ship’s DEX modifier to the roll. Individual players and NPCs do not roll for Initiative
separate from the ship they are aboard, unless or until hand to hand combat on deck is
initiated either through a Board action, or if individual enemies appear on the players’
ship. When battling Huge or Gargantuan sea monsters, the ship(s) and monster(s) each
roll initiative normally.

Combat Basics
When a ship is engaged in combat with another ship, its crew can carry out any of its
available actions as described in the ship’s *stat block. By default, a ship’s weapons are
manned by its crew, and each weapon makes their attacks separately. Player
Characters may decide to man any of the ship’s weapons in place of a crew mate; in
that case, the player will need to use the Disengage action in order to stop manning the
weapon. The captain of a ship (either the DM or a player character with the *Captain
background), may also call out a number of Orders equal to the number of Player
Characters aboard the ship at the start of the ship’s turn. These Orders are then carried
out by the Player Characters, with each player enacting a single Order during the ship’s
turn. Typically, carrying out an Order consumes the player’s action for that round of
combat. See Orders for a complete list of actions players may take during ship to ship
combat.
A ship sinks if its Hull drops to 0 hit points, OR if the Hull sustains damage and takes on
too much water. Any time the Hull is damaged for the first time during a round, water
begins flooding in. For each round the ship is taking on water, it loses 5 feet of
movement. If the ship’s speed reaches 0 feet in this way, the ship sinks. Bailing through
the Repair order removes enough water to restore 5 feet of movement to the ship.
Orders
The captain of a ship on which player characters are crew members or passengers may
call out a number of Orders equal to the number of player characters at the start of the
ship’s turn in combat. The same Order may be called out multiple times on the same
turn unless otherwise stated. NPC ships may replace either of their normal actions for
one Order on their turn.
● Take Aim- The captain issues this order when they want an attack to target a
specific part of another ship other than the hull. These parts include
*sails(movement), the *rudder(control), the *helm(control), and weapons
● Fire-. One ship attack gains advantage for its turn. One Player manning a ship
weapon will roll their attack with advantage.
● Repair- one area of the ship gains 2d10 HP. A player will roll the dice to make
the repair. The captain may call out a specific area to be repaired, but if they do
not it is up to the player’s discretion. If the player has the *Bosun background,
they repair a total of 4d10 HP. Alternatively, the captain may give this order to bail
water from the hull, removing enough water to restore 5 feet of movement per
Repair order given.
● Drop/Raise Anchor- The ship stops moving. The ship can begin moving again
only after the anchor has been raised. Dropping or Raising the anchor is one
player’s main action for the round. If the anchor is dropped, it cannot be raised
again until the ship’s next turn. If the anchor is raised, it cannot be dropped again
until the ship’s next turn. Dropping the anchor in the *Open Ocean environment
has no effect.
● Ram- The bow of the ship must be perpendicular to the hull of another ship, and
be at least 120ft. Away from the target. The ship collides with another ship. A
player makes an attack roll and damage roll. The attack and damage modifier is
1 + the ship’s STR modifier. A successful ram attack deals 22 (3d8+2)
bludgeoning damage.
● Brace- NPC crew members cannot be killed from enemy ship attacks until the
start of the ship’s next turn. All players gain +5 bonus to AC, under 3 ⁄ 4 cover
until the start of the ship’s next turn as long as they remain on the deck of the
bracing ship.
● Board- The bow or either broadside of the ship must be within 30ft. Of the bow
or either broadside of another ship. All players given this order are dispatched to
the deck of the other ship. Player Characters can choose which space they land
on as long as it is no further than their movement speed, beginning from the
closest space to them on the ship they are boarding. Usually, hand to hand
combat is initiated. Boarding consumes the player’s movement for that turn, but
not their action.
 ● Act Freely- Player Characters may take their turn normally, to cast a spell for
example.

Crew Casualties
As a ship takes significant damage, its crew will suffer casualties. If one movement or
control part is destroyed, 1d6+1 crew members perish. When the hull of a ship drops to
or below 25% of its total hit points, 1d8+2 crew members perish. Once a day, if a crew
suffers casualties, their *Morale will decrease by -1. If the hull of a ship drops to 0 hit
points, the ship is destroyed, and 50% of all remaining crew members perish. This
constitutes severe casualties, and the morale of the surviving crew members drops to -1
if it was not already below -1. A typical crew member uses the commoner stat block in
the fifth edition Monster Manual, and as such is vulnerable to monsters during a
boarding/hand to hand combat situation.

Special Scenarios
Pirates at sea are known to capture enemy ships, and will often take prisoners if
they think they would be useful or fetch a handsome ransom. Likewise, military vessels
are always on the lookout for pirates, and will seize the opportunity to capture any
pirates they come across. Player characters, especially those with suitable
*backgrounds, may find themselves prisoners aboard an enemy ship. While at sea, they
will be confined to the brig until they are set free or escape on their own. The players
will not be directly involved with any combat the ship they are imprisoned on becomes
engaged with. If they escape the brig during a battle, combat encounters below and on
decks should be handled just like any other combat encounter. If the players manage to
commandeer the vessel, they may engage in Ship Combat, provided they can somehow
convince the crew of the ship to cooperate.

Combat Objectives
Combat aboard a ship still presents many possible objectives beyond just hack
and slash. These objectives are different based on what the larger objective of the battle
is: Are the PCs wanting to destroy the ship, or board and capture it? Do they want to
secure the treasure it has aboard, which sinking the ship would make very difficult to
accomplish? Are they trying to escape an enemy ship? Whatever the case, here are a
few examples of common objectives PCs might have, and whether or not it constitutes
combat, or perhaps a series of skill checks in the midst of the larger battle.
● Slay the enemy Captain/Officers, Slay a certain number of crew members.
When PCs want to board and capture a ship, at least two from a combination of
these objectives will be effective in rendering the ship disabled and ripe for
 capture. The objectives themselves are quite straightforward: fight until the
enemy is slain or surrenders.
● Destroy the ship’s flag, destroy powder reserves, poison provisions,
plunder the hold. These objectives are excellent for sabotaging enemy ships,
either by decreasing the crew’s morale, or damaging the ship internally,
effectively crippling it. These objectives may be better suited to a sort of
exploration encounter under the cover of a heated battle. There would be intense
skill checks involved, the failure of which would have predetermined
consequences. For example, the ship’s flag is aloft its highest mast, and one PC
attempts to destroy it to deal a devastating blow to the enemy crew’s morale. The
character would need to make either an Athletics (Climbing) check, or a DEX
check for every 10 feet they move vertically, up to about 30 or 40 feet, depending
on how tall the mast is. The DC can increase in difficulty as they get higher where
there are less handholds, and the mast sways as the ship endures the pitch and
toss of battle. A series of successful checks allows the PC to complete their
objective, but a single failure will see the player plummet to the deck below,
suffering fall damage, and possibly a lingering injury.