With the decision to give my characters in Escarren a ship, I came to the realization that I couldn't expect them NOT to use the cannons, especially when they've already met with pirates as well as a Kraken whelp. In the spirit of allowing for some good-old swashbuckling, I've adapted Pathfinder's rules in order to simplify them a bit and have developed a strategy for boarding another ship, should it occur.
When doing ship combat, the 1x1 battlemap changes from representing 5ft squares to representing 30ft squares. Using the directional chart for a thrown weapon, a d8 is rolled to determine the direction of the wind (Or the DM can determine it).
Initiative - Initiative is rolled using the initiative score of the designated captain. Assuming that the PCs are all on the same boat, they can discuss actions and decide actions democratically or can assign one person the task. In some cases, (Such as in the Escarren campaign) the Initiative stat may come from an NPC captain who owns and runs the ship that transports the PCs around.
Movement - On the captain’s initiative count, the ship can move its current speed in a single round as a move-equivalent action for the captain (or double its speed as a full-round action, as long as it has its minimum crew complement. The ship can increase or decrease its speed by 30 feet each round, up to its maximum speed. Alternatively, the captain can change direction (up to one side of a square at a time) as a standard action. A ship can only change direction at the start of a turn. When not moving, your ship loses all "dexterity" it has, taking a -5 penalty to AC as well as an addtional -2 pentalty.
Attacks - A ship with more than its minimum crew can take attack actions during their initiative pass. Depending on the position of the ships, not all guns may be able to be fired at an enemy at once and few ships have backwards facing guns, thus you are not able to attack backwards. Cannons take one round to reload after being fired.
- Broadsiding - Provided the enemy ship is parallel to the player ship and no more than 3 squares away, you may broadside as a full-attack action. When broadsiding, you fire all your cannons at once, making a single attack roll at a +2 bonus (+4 if the ships are adjacent). Damage is added together and percentile die is rolled to see if there are additional effects (see Table 1.1). Optionally, take the average damage of a single weapon and multiply it by the number of weapons in the broadside to determine the total damage dealt.
For example, a sailing ship with a bank of 10 light cannons on its port side fires a broadside attack. A single light ballista deals 3d8 points of damage, for an average of 13.5 points of damage. If the attack hits, the broadside deals 13.5 × 10, or 135 points of damage. Note, however, that you cannot move after making a broadside until the next turn. You may maintain a broadside, rushing your crew to reload, with a DC 30 skill check (Profession: Sailor or other appropriate skill)
|1%||Captain hit directly, takes full damage from one cannon.|
|2-10%||Captain hit by shrapnel, takes 1d8 damge.|
|11-25%||Crew damaged, Reduce the enemy's crew points by 1d4, 1d8 on critical hit.|
|26-74%||Reverberating Blow. Re-roll 1d3 dice worth of cannon damage.|
|75-94%||Secondary Mast hit. Split 2d8 worth of Damage to Sail HP (Doubled if critical)|
|95-100%||Main Mast hit. Split 4d8 worth of Damage to Sail HP (Doubled if critical)|
- Ramming - A ship can also attempt to ram a target if it has its minimum crew. To ram a target, the ship must move at least 30 feet and end with its bow in a square adjacent to the target. The ship’s captain then makes a Profession (sailor) check— if this check equals or exceeds the target’s AC, the ship hits its target, inflicting damage as indicated on the ship statistics table to the target, as well as minimum damage to the ramming ship. A ship outfitted with an actual ram siege engine inflicts an additional 3d6 points of damage to the target (the ramming vessel suffers no additional damage).
AC, Hitpoints, and Crew Points - The AC of a ship is determined by its base AC plus the captain's Profession (Sailor) skill. Touch attacks, such as those from spells, ignore the skill bonus. Hitpoints come in two forms, the basic ship's hitpoints and the sail hitpoints. Sails can be targeted specifically at a -3 penalty to hit and take half damage due to being hard to hit unless chainshot is used. Ships also have a hardness of 5, effectively giving them DR5/-. Crew Points is basically just the starting crew for a ship and is used to represent loss of life during battle. On a critical hit or if using cannister shot, remove 1d4 crew points. Stats given on the PFSRD website represent the minimum crew necessary to move the ship and does not include crew for cannons. When a ship reaches half its sail hitpoints, it reduces its movement by half. When it reaches 0 sail hitpoints, it cannot move. If the ship itself reaches 0 hitpoints, it gains the sinking condition and will sink in 10 rounds. Additional damage to the ship reduces the time to sink by 1 round for every 25 damage.
In order to board an enemy vessel, the captain must make a CMB+his skill bonus versus an adjacent ship's CMD. If the ship attempting the grapple has boarding hooks, you gain an additional +4. Once two ships are grappled together, both ships stop moving and the captain with the higher initiative chooses to attack or wait for the enemy to come to them. Once the ships are grappled, combat shifts back to working completely as normal, albeit in a narrow battlefield. If the waves are particularly fierce, due to storms for example, movement on-board the ships counts as difficult terrain.
The captain of the ship can decide to spend some of his crew across to engage the opposing crew. These crewmen only can officially make move actions all on the same turn, but enemies they approach before a PC does are considered in combat. Crewmen count for flanking bonuses and other team or positioning ability and are affected by indescriminate AOE damage spells. At the end of a turn, an even-odd roll takes place (Or a coin toss). Whichever side wins removes 1d4 crewmen from battle.
Other Means of Boarding
Various other means can be used to cross from one ship to another with varying degrees of difficulty. Jumping can normally only be done if the ships are grappled and still requires a high skill DC. Swinging across using rigging can be done, but requires an Acrobatics check to get across safely. If you use this technique to attack a foe with a kick, use the rules for bullrush, but add +4 to the check to determine how far the target is pushed back, otherwise it just counts as a charge attack. Spells, such as dimensional door, work normally as a means of working from one vessel to another.