Naval Combat

On the seas of Aegeon, naval combat is more often than not to come up. So when it does, these are the rules.

Starting Combat

When Naval combat begins the party does a flat roll of initiative. The highest roll becomes the initiative count for the crew. If the party is part of two separate vessels, then the members of one crew can roll initiative for one vessel and the members of the crew can roll for the other.

During combat the party represents the members of the crew. During their initiative the party gets to use one Officer actions. They can use these actions based on the roles either they play, or are able to perform. Only one can be the Pilot, however, and must be decided at the start of combat. It is wise to let those proficient in water vehicles be the pilot as they can use their proficiency score in navigating and moving the ship.


The size and speed of a ship is dependent on the number of sails and the ship’s ability to sail. Each space represents 30 Ft.

A keelboat has one mast and sails at 120’ per turn.

A basic sailing ship has 2 masts and will sail at 150’ per turn.

A caravel will sail has 3 masts and will sail at 180’ feet per turn.

A longship has 4 masts and will sail at 210’ ft per turn.

A Galley has 5 masts and will sail at 240’ ft squares per turn.

Turning requires a piloting check and to turn requires 30’ of movement. Every cardinal direction turn after that requires 30’ more square of movement after the ship has turned.

Catching the wind allows the boats to move an additional 30’ feet. Going against it comes with a penalty of 30’ ft. Same for waves and currents.

Long Range

Before a sea battle, ships are often out of the range of cannons, but there’s still lots strategy and actions for players. When noticing another ship consider the following options.

Scan. Look at the ship with a spyglass or your naked eye. With this they can roll any skill check they think can help them discern anything about a ship (such a alliances, flag’s, ship types, weaponry, etc.)

Stalk. Decide to follow the ship from a distance and maintain that distance. DC is determined by DM.

Hail/Approach: Figure out a way to communicate this with flags or some other form of long range communication

Hide. Clear weather in the open sea would make this impossible, but tough weather or a jagged coastline filled with inlets can make hiding rather easy. DC is determined by DM.

Drop Barrels. If a ship is being chased it can drop fire barrels or other items in its wake, forcing the pursuing ship to risk taking damage or taking another course.

Hoist a Flag. You can hoist any flag you have in your possession. This can be used to fake-out enemies, appear neutral, surrender or call for a parley. When trying to fake out enemies, the opposing ship should make a check similar to when someone is wearing a disguise.

Magic. It might be a good idea to cast protection or other spells for combat before getting into the range of cannons and attack magic.

Officer Actions

During combat every play also has access to an officer action. These roles must be assigned at the start. Some allow switching mid combat. Some do not.

Captain/First Mate

Rally. Player can intimidate/inspire the crew once per battle for an advantage on a roll. Make a Charisma check with a DC of 10 (or higher if crew is disloyal or in real trouble. DM Discretion).

Weak Spot. Allow player to look for a weakness in the defenses of the enemy’s vessel. Make an Intelligence check with a DC of 15 (adjust for conditions, DM Discretion) to spot a weakness and give advantage on the next attack roll that targets that weakness


The pilot can make a Dexterity check to make sure they are controlling the ship well, failure can result in the ship slowing, not turning, etc.

The helm must be controlled by a player or NPC or the ship will be drifting.

For pilot checks you can add the pilot’s DEX modifier and proficiency to the roll if they have proficiency with water vehicles or sailing.

As an optional rule you can add the pilot’s DEX modifier to the AC of the ship if they are a skilled pilot.


At long range, have your players aim the big guns. Three crew are required to operate a full size cannon, as there are three sequences of actions needed to fire it.

At close range: Man the swivel cannons and roll the attacks and damage. Only two crew are required to operate a light cannon.

Have an officer or master gunner can add their Dexterity or Proficiency to all attacks whichever is higher.

If no officer is in charge of the guns, then a cannon’s attack bonus should be only +2

Weak Spot. Allow player to look for a weakness in the defenses of the enemy’s vessel. Make an Intelligence check with a DC of 15 (adjust for conditions, DM Discretion) to spot a weakness and give advantage on the next attack roll that targets that weakness


have them make their own attacks, put out fires, mend the ship, etc.


A ship’s surgeon must have some kind of clerical/healing skill. The surgeon can restore 1 crew member per turn, DC 10 with any related modifiers added on.

Taking Damage

When a ship is hit, they can take damage either at the sails, the rowing oars, or the hull. Each comes with their own HP

Sails and Hulls take damage until they are at zero. If a sail is at zero then the ship’s movement lessens by 50’ for every sail missing. If a Ships hull is at 0, they are stalled and cannot move until repairs can be made. Mending cantrip cannot be used to repair a ship.

When a ship is stalled then another ship can board it with no penalties or checks.

If the rowing oars are down to 0, then they are broken and cannot be used for further movement.

For every damaging hit upon a ship 1 crew member is knocked unconscious. The player playing the role of a surgeon can roll a medicine or wisdom check (DC 12, also changes with DM discretion) to stabilize the crew member. Another successful check can save a crew member. Using a healing spell or healing potion can also save the crew member and get them back up after being hit. Multiple person healing spells can heal multiple downed crew.

The party does not count in the overall crew’s count until all other crew members have deceased. Once they are left they can stay to fight it out and combat proceeds as normal, or they can chose to try and flee.


Making the cannons fire requires three actions: one to load, one to prep, one to fire. Once firing happens the sequence begins again. Once the Loading and Prepping have done, the party can hold off on Firing until they are ready.

All shots use the DEX score to attack. If the attacker has proficiency with heavy fire ranged weapons or siege weapons, then they made add their proficiency modifier. Upon meeting or succeeding the target ship’s armor class, the player who made the shot rolls the damage dice.

Every ship has a Damage Threshold. If the damage dice rolled does not meet or exceed the Damage Threshold, then the targeted ship takes no damage.

Light Cannon:


range 300 feet/600 feet,

hit 4d8 bludgeoning damage.

It takes one action to load and fire a cannon, unless the action is handled by two player characters. Can be manned by one or two crew and it can be turned to attack nearly any target, but it is recommended not to fire across your own boat.

Medium Cannon:


Range 600 feet/900 ft,

Hit 6d10 bludgeoning damage.

Heavy Cannon:


Range 900 feet/1200 feet,

Hit 8d10 bludgeoning damage.

Swivel cannons are positioned on the top deck and can be used to attack from bow and stern. They can also be used to attack crew and sails.

Other siege weapons can be used if the ship has them.


To ram a ship is to simply hit your ship into the enemy ship.

You must be at least 30′ away from the other boat and end your turn reaching the other ship. Attack: 1d20 + proficiency + dexterity versus the AC of the other ship or versus a pilot check (your choice). Damage: Speed of Boat (in feet per round) x 1d4 bludgeoning damage, the ramming ship takes half of the damage to itself Example: 30′ x 1d4 (rolled 3) = 30′ × 3 = 90 hp bludgeoning damage to enemy ship, 45 hp bludgeoning damage to attacking ship. If the attacking ship has a battering ram you can roll a d6 and take a quarter damage instead.


The act of bringing your ship up against/alongside an enemy ship with the goal of capturing or destroying it.

To board an enemy vessel the pilot must first approach the enemy ship. The pilot makes a DC 10 pilot check. If the boat is disabled, this happens without a check. If the ship that’s being boarded has certain effects (such as fleeing or is still in full control) then the DC is 15 or 20.

Other players can use their own actions to aid in the boarding attack by using grappling hooks, employing boarding nets, swinging over on ropes, dropping a bridge, etc.

A ship that has been boarded can attempt to escape. The pilot can make a piloting check at a disadvantage to escape. If the ship is stalled (0 HP) then this option can not happen.

Once a ship is fully boarded then normal melee rules apply.

Naval Combat

An Aegeon Odyssey ManOnFire777