Each ship takes up one square on a battle mat. The battle area is defined as a square approximately one mile on a side, consisting of a 20x20 grid where each square is 250 feet on a side. If multiple ships in different vectors are involved, a larger 40x40 grid may be used. Generally speaking, ships cannot engage outside of 5000 feet without resorting to non-combat rules.

The point of view is always from the PCs' ship. If they have more than one, they may choose which is the primary ship. Unless the PCs' primary ship is surrounded and being approached from all angles, combat generally begins with the PCs' ships on one edge of the square, and the enemy ships on the other edge.

Initiative is rolled as normal, with one roll per ship. Any number of methods may be used to subdivide the PCs' round, such as handling actions in a clockwise or counter-clockwise direction around the table, or simply allowing the PCs to go in arbitrary order.

Combat takes place in rounds, the same 6-second rounds used in normal combat. This allows for normal combat rules to apply where necessary. For instance, a wizard can cast fireball on an enemy ship once per round.

Rounds are divided into 2 phases; the action phase and the movement phase. The action phase always comes first.

In the action phase, all PCs and enemies take their actions, in initiative order. Those actions can affect the movement phase; for instance, each helmsman decides what course to follow each round.

In the movement phase, all ships move, in initiative order, according to the actions taken in the previous action phase by the helmsmen and sailors, and the conditions of the ship prior to the current round.

In various circumstances, two ships must vie for advantage. For instance, an advantaged ship can place itself outside of a given gun arc while keeping the target ship inside its ideal gun arc.

In a case requiring a check for advantage, each captain rolls a Profession (sailor) check; the same modifiers apply to this check that would apply to any helmsman maneuver.

Every creature involved in the battle can serve at a given task. Multiple creatures can have the same task, as defined below. A creature's task determines his options in each round.

To change task, a creature must first select no task as a standard action. A creature with no task is simply standing around on deck. He can take normal actions in this position. As a standard action, a creature with no task can take up any available task.

The captain of a ship may be a leader, but there is no specific task for him. He can take any available task.

Helmsman

The helmsman controls the rudder, and issues instructions to the sailors. Helmsmen can take the following actions:

• Course change
• Evasive maneuvers
• Ram

Only one creature may be the helmsman on any given ship. This position grants improved cover (+8 cover bonus to AC, +4 cover bonus against area-effect spells, half damage from area-effect spells).

Sailor

Sailors play a vital role, modifying the sailing plan as needed to support the actions of the helmsman. The minimum number of sailors on a given ship is given in that ship's description.

If a ship has between 50-99% of the minimum number of sailors, then all actions of the helmsman are delayed 1 round, and all Profession (sailor) checks she makes suffer a -5 penalty.

If a ship has between 25-49% of the minimum number of sailors, then all actions of the helmsman are delayed 2 rounds, and all Profession (sailor) checks she makes suffer a -10 penalty.

Sailors take no actions by themselves. Generally, henchman or hirelings are expected to fill this role. This position grants cover and concealment.

Spotter

A spotter, mounted in a crow's nest or other advantageous position, can help the rest of the crew determine the layout of the battlefield. With at least 1 spotter in position, a ship's crew is aware of the battle mat. With no spotter, the following penalties apply:

• 20% miss chance on all ranged attacks outside the first range increment
• No ability to see beyond the battle mat for any possible newcomers to the battle
• No advance warning of approaching hazards; helmsman cannot use Evasive Maneuvers action.

A spotter can take the following actions:

• Fire support
• Take total cover

This position grants cover and concealment.

Gunner

A gunner operates the ship's weapons. Normally, gunners are crew members on siege weapons; the rules for firing such weapons are given in the weapon's description.

This position grants cover. In a gun deck, it grants improved cover.

Battle Watch

While under fire from enemy ships, a ship needs constant attention from able-bodied individual to put out fires, stay loose lines, and generally counteract the chaos caused by enemy weapons. A creature on battle watch can take the following actions:

• Put out 1 fire
• Remove 1 wounded crewman from danger
• Remove 1 hazard from the deck
• Sever 1 boarding line or grappling hook

Marine

Marines stand ready to board enemy ships, or defend against enemy boarders. They generally keep out of the way when no ships are in range, but must be on deck and ready at least 1 round in advance in order to board or defend.

A marine can take the following actions:

• Stand ready
• Stand down
• Cast boarding line
• Sever 1 boarding line

Once boarding occurs, ship combat is suspended, and normal combat begins. Marines who stand ready always act in the first round.

Sniper

In this position, one can make attacks from the vantage of a spotter. In essence, a sniper is his own spotter, and thus does not require fire support. Also, being in this position provides sufficient concealment to attempt Hide checks.

It takes 2 standard actions, rather than 1, to enter or exit this position.

This position grants cover and concealment.

A ship's speed is given in its description. In most cases, a ship's speed is much less than 250 feet, and thus it cannot move one square per round. Instead, it has a certain number of rounds required to move 250 feet, called Turns-to-Square. It takes that many rounds of movement to exit a square in a given direction, which must be chosen prior to beginning the movement.

Optional Rule: carrying over excess movement

Many ships move at a speed that does not evenly divide into 250. Normally, a ship's Turns-to-Square rating truncates all excess movement. In many cases, a significant amount of a ship's speed is effectively wasted. In an extreme case, a ship with a move speed of 245 would still need 2 turns to enter a new square, thus wasting 240 feet every other round.

With this optional rule, you determine your ship's overage by multiplying your speed times your Turns-to-Square and subtracting 250. The result will be a number less than 250.

Every time you enter a new square, the overage accumulates. Each time the overage passes 250 ft, reduce the overage by 250 ft. The next round of movement, you move one square. Since overage accumulates in the same turn you move, delaying the bonus movement prevents you from moving 2 squares at once.

Affecting Movement

A sailing ship maintains its heading and speed automatically, with minimal handling of the ship's wheel and its sails. Thus, the helmsman must act only when she desires to change the ship's heading or speed. On the same token, the sailors need not act until the helmsman issues new orders.

The helmsman must remain in position even when not taking actions, though this is not true of the sailors.

Heading

For the sake of simplicity, a ship's heading must be either parallel to the lines on the battlemat, or at an exact 45 degree angle to any line. All ships have a maximum course change in degrees which corresponds to this limitation.

Course Changes

If you change course in the middle of a square, the number of rounds it takes to reach the next square doesn't change. Thus, if it takes your ship 8 rounds to cross from one square to the next, then no matter what course changes are made inside that square, the ship arrives in the square into which it is heading after 8 rounds of travel.

Speed Changes

A sailing ship has several speeds; generally, these are multiples of its base speed. When the ship travels at these speeds, it changes the number of rounds required to cross from one square to another. If your ship's speed changes in the middle of the square, just use yer damn head.

By default, all attacks, whether the personal attacks or spells of a free creature, or the armaments or ram of a ship, target a ship as a whole. A ship's AC and special defenses assume this kind of attack.

Hitting the Ship

A ship is an object, like any other. It has an AC, hardness, and various resistances (see the SRD). The following modifiers apply to attack rolls against a ship.

====Profile====

A target ship's heading relative to your ship's heading and firing arc is its profile.

The possible profiles are:

• Narrow: +10 to target ship's AC
• Oblique: +5 to target ship's AC
• Broad: +0 to target ship's AC

When the target ship is moving directly toward or away from your ship in its firing arc, it is in the narrow profile. When it is moving at a 45 degree angle, it is in the oblique profile. When it is moving perpendicular, it is in the broad profile.

====Motion====

The motion of your ship, and that of the target ship, both have an effect on the accuracy of any ranged attack. For each vessel's speed, add the following modifiers to any attack rolls.

Your ship's speed

• 0-30:No modifier.
• 31-60:-2 to your attack rolls
• 61-90:-4 to your attack rolls
• 91-120:-6 to your attack rolls
• 121-150:-8 to your attack rolls
• 151-180:-10 to your attack rolls
• And so on.

Target ship's speed

• 0-30:No modifier.
• 31-60:+2 to target ship's AC
• 61-90:+4 to target ship's AC
• 91-120:+6 to target ship's AC
• 121-150:+8 to target ship's AC
• 151-180:+10 to target ship's AC
• And so on.

Called Shots

Any attack can also be targeted at specific crew members or specific subsections of a ship. These are "called shots".

====Focusing attacks====

You can focus all attacks on a given section of the hull. The section's actual location is irrelevant (though it is specific to one quadrant of the ship).

To target a given hull section, you must hit the ship's AC +10, and your ship must be in the firing arc of the quadrant on the enemy ship you are targeting.

If you miss, you do no damage. If you hit, you inflict damage as normal, but the total damage to the targeted section is kept track of separately.

When the damage in a section exceeds 10% of the ship's total maximum hit points, you inflict on one section, you cause a leak in the target ship (see [#Leaks|Leak]).

You may target any number of sections within each quadrant, each springing its own leak. Once you've caused a leak in a section, it is useless to continue attacking that section, so you would naturally progress to a new section.

The enemy ship can deny you the ability to target a section by rotating the quadrant out of the line of fire.

====Targeting an individual====

To be aware of the existence and position of an individual, the target ship must be within 1 square

---

i.e. either adjacent or within your square.

A spotter can provide fire support to your called shot, granting this benefit at a distance of several squares.

Each position grants its own amount of cover or concealment. Also, the ship may have additional special defenses which protect crew members.

Other than that, targeting an individual is no different than it would be in normal combat.

====Sweeping the deck====

A cannon loaded with grape shot, an area-effect spell, or even an ordinary weapon or spell can be used to perform this type of called shot.

This allows you to strike indiscriminately against crew members in the following positions: sailor, battle watch, marine, gunner (above deck).

To attempt this kind of shot, make an attack roll against the ship. If you hit the AC, you may have hit one crew member. For each 5 points by which you exceed the ship's AC, you add one potential hit.

Determine the targeted crew members randomly. Once the targets are known, determine if the attack actually hit. Finally, for each target actually hit, apply a 50% miss chance.

A cannon loaded with grape shot has a +10 to this kind of attack.

====Targeting the sails====

Sails have their own AC and hit points, and are targeted independently of the ship. Generally, the AC of sails is much higher than the ship's base AC, since it is difficult to place a direct-fire attack that inflicts significant damage to the sails.

A cannon loaded with chain shot has a +10 to attack sails.

Fire

Fire is one of the most powerful weapons to wield against a ship. Flaming projectiles, explosive cannonballs, and spells can all be used to start a fire.

====Starting a fire====

To start a fire, you must hit a ship with a weapon that causes fire. Flasks of alchemist's fire and firestarter cannonballs are examples of mundane weapons which can do this. Each of these attacks start one fire if they hit.

Spells which inflict fire damage can start a fire if they hit the ship. As a rule of thumb, a fire spell starts one fire per instance of contact. Thus, a fireball starts one fire, while a flaming sphere can cause one each round in different parts of the ship. Firebrand can cause many fires all at once.

====Effects of a fire====

Each fire is considered a separate entity. It is not in a specific location, and therefore does not target a specific quadrant. Rather, it affects the ship as a whole.

A fire burns for 1d6 damage per round, which bypasses a ship's normal energy resistance (but not any special fire resistance it might have).

====Putting out a fire====

A crewman on battle watch can put out a fire as a standard action. A quench spell removes up to 4 fires at a time.

Firing Arcs

Many ships are equipped with weapon mounts which are restricted to a given gun arc (fore, aft, port, starboard). Some mounts may allow access to multiple, but not all arcs. In this case, these weapons can only be fired on targets within the appropriate gun arc.

On the battlemat, a ship's firings arcs are simply 90 degree arcs. Thus, targets between -45 and 45 degrees from a ship's heading are within its fore arc. If the target falls directly on the dividing line, it is in whichever arc is most advantageous.

A ship has a certain number of hit points; if it reduced to 0 hit points, it is destroyed, and it sinks. However, prior to reaching 0 hit points, there are significant negative effects to damage. At each of several thresholds, the ship gains new penalties, as listed below.

Below 75% hit points

All checks for the helmsman suffer a -5 penalty. Speed is reduced by one-third (round down to 5 ft increments).

Below 50% hit points

All checks for the helmsman suffer a -10 penalty. Speed is reduced by two-thirds. Ship gains 1 leak.

Below 25% hit points

All checks for the helmsman suffer a -15 penalty. Speed is reduced to 5 ft. Ship gains 3 leaks.

Below 10%

Ship begins to sink (5% per round).

0 hit points

Ship sinks at additional 5% per round; this 5% cannot be bailed.

Leaks

Hit point damage and concentrated fire can cause leaks. When the ship has a leak, it takes on water.

For each leak, 4 men on battle watch are required to bail the water. If less men are assigned to that leak, the ship takes on more water than they can bail.

Each leak causes 4% sinking per round, -1% per man bailing water.

Men on battle watch who are not bailing water can repair a leak; for every two consecutive successes on a DC 20 Craft (shipbuilding) check, 1% of a leak is repaired. Each check requires 10 pounds of wood, 1 pound of hardware, and one round to complete. When all 4% of a leak is repaired, the leak is stopped. These repairs are only temporary, and expire after 24 hours, so real repairs must be made after the battle.

Sinking

Sinking is measured in percentage of water taken on to sink. At 100%, the ship sinks.

A man on battle watch can bail 1% of the water per round. When a ship reaches 0 hp, it sinks without the ability to bail water.

Carpenters can repair hit point damage to a ship, but not fast enough to save a sinking ship. Emergency leak repairs do not affect sinking based on the ship's hit point damage. To save a ship that is below 10%, men must bail water continuously while carpenters repair hit point damage to the ship (see [#Repairs|Repairs]).

Repairs

Outside of combat, carpenters (anyone with ranks in Craft (shipbuilding)) can repair hit point damage to the ship. It requires a DC 10 Craft (shipbuilding) check, 1 hour, 10 pounds of wood, and 1 pound of hardware. On success, the ship is repaired of 5 points of damage.

Magic can also be used to repair hit point damage; spells such as Repair Light Damage exist for this purpose. These spells cannot affect a ship (or any object) reduced to 0 hp. Other spells may exist to repair such ships (or objects).