Abstract Ship Combat (Apath)
|Unofficial rules compendium|
- This is a work in progress.
These rules are designed for two ships or small fleets of ships, where one side tries to intercept and the other tries to escape. The interceptor is called the hunter, the ship trying to escape is called the prey.
Ships are specks on the horizon, at first only visible from the mast top. Even a small obstruction, such as heat haze, can hide a ship at this range.
Ships roll opposed Perception. If one side has a perception advantage the other lacks, such as lowlight vision at night or high-flying scouts in the day, it gains a +5 bonus. The side that wins chooses which ship has the advantage in the first turn of interception (usually selecting the opponent ship). If the margin between rolls was 10 or higher, the winning ship can choose to avoid ship combat altogether or to avoid the chase and go directly to long range with the advantage.
Now ships have a good opportunity to study each other. Hulls become visible, revealing a lot of significant detail about the other ship. Flags are displayed at this range if not earlier; a ship refusing to show the flag at this range can be presumed to be hostile.
If both want to engage or avoid each other, there is no chase; end the action or go directly to long range, as appropriate. It is also possible to avoid the chase by trickery, subterfuge, use of illusions, and such. This is left to the [[GM]'s discretion. The rules assume a straight-forward chase takes place. The side that rolls the highest decides whether to break away or engage.
During a chase, both sides roll Profession (sailor).
- The faster ship gaining a +5 bonus to the roll.
- If multiple ships pursue a single ship, they can roll individually.
- If the ships stick together, either as pursuer or prey, each rolls and all use the lowest result.
The length of the chase, in hours, is equal to the losers die roll minus half the winner's die roll. High rolls and a small margin result in a long chase. Note that events and encounters can happen during this time, invalidating the chase. The pursued vessel might even reach a friendly port.
3 Interception Combat
Once ships come within a few hundred feet of each other, interception combat begins. This is still abstract, but much more like an ordinary combat, with ships acting instead of individuals.
Leeward and Windward
In the following text, the terms leeward and windward is used for the tactical position of ships. In nautical terms, a windward ship has a position upwind and a leeward ship has a positon downwind. In game termsa ship to leeward has a maneuvering advantage in pursuit, and chooses next turn's maneuver. A windward ship has a combat advantage, and decides what tactic to use.
Interception combat is fought in turns of one minute each. During each turn, each ship can both maneuver and fire. Each turn plays out like this. The attacking ship picks first turn's maneuver.
- The leeward ship from last turn picks a Maneuver, and both sides make opposed rolls to determine wind position for the rest of the turn. The side that wins decides whether to be leeward or windward during the rest of the turn. The opposing ship takes the other wind position.
- The the windward ship picks a Tactic
- Resolve all attacks from the windward ship, then resolve all attacks from the leeward ship. Each attacker has a full rounds worth of action. A combat turn is one minute long, but each attacker only has a clear line of fire during a single round. The remaining time is spent waiting for an opportunity, reloading and so on.
- Change range as appropriate for the Tactic used.
- If a boarding action occurred, ship combat ends and personal combat begins.
- If range is increased beyond Long, ship combat ends and a new chase begins. Both sides suffer a -10 penalty on Profession (sailor) checks in a subsequent chase (the only effect of this is to reduce the length of the chase).
Ship combat happens at different ranges, and depending on the range it works quite differently. The approximate distance between ships and the available maneuvers depend on the range.
- Distant Range: Range extended long-range spells and long-range missile weapons can first fire at this range. Assume 800 ft.
- Long range This is wehere regular spells and missilie weapons becomeeffective. This is assumed to be 400 ft., long range for spells in most cases.
- Medium range is where weapons and spells become really effective and ship combat can start in earnest. Medium range is assumed to be 100 ft.
|Distant||800 ft.||Evade, Chase, Broadside||Bluff, Outmaneuver, Race|
|Long||400 ft.||Evade, Chase, Broadside||Bluff, Outmaneuver, Race|
|Medium||100 ft.||Evade, Chase, Broadside, Boarding, Ramming||Bluff, Outmaneuver, Race|
Tactics represent attack vectors that the windward side can choose. Firing opportunities are generally mutual; either both ships fire, or neither ship fires.
- Evade: The windward ship seeks a position where weapons will not bear, reducing the amount of attacks possible. No siege weapons may fire, but normal missile weapons and spells may. The windward ship can increase or reduce range by one category.
- Chase : The hunter can fire any forward-firing or swivel-mounted siege engines. The prey can fire any rear-facing siege engines. Spells and missile weapons fire normally. The windward ship can increase or reduce range by one category.
- Broadside : Both ships can fire their side-mounted and swivel siege engines. Spells and missile weapons fire normally. Range does not change.
- Ramming : The windward ship can fire any forward-firing weapons. Spells and missile weapons fire normally. Then the leeward ship fires a broadside. Then the windward ship rams the windward ship and decides whether to board or to disengage. Boarding is bow to side.
- Boarding : Spells and missile weapons fire normally. Siege engines may not fire. Then the two ships come up alongside and boarding begins. Boarding is side to side.
Maneuvers are used to gain advantage. The leeward ship from last turn decides what maneuver to use. Suitable magics add spell level to the check, one spell per side. Except Race, a maneuver that fails cannot be used again in this battle.
- Race : This is the default maneuver. Both sides roll Profession (sailor), with a +5 bonus to the ship that has a higher maximum speed.
- Bluff : Tactics like fake flags or other subterfuge. Leeward ship rolls Bluff vs. The windward ship’s Sense Motive.
- Navigate : Using terrain, wind, and waves against the opponent. Each side rolls Knowledge (geography) or Survival in an opposed check. Ships in home waters may also use Knowledge (local).
In ship combat, only ships and targets away from ships can be targeted, not individual crew members on board ships. An attacker can choose to attack the target ship's hull, or a propulsion system (rigging, oars) in use.
Attacks must hit the ship in order to cause damage, and saving throws are allowed as normal. To determine a ship’s actual saving throw modifiers, add half the pilot’s sailing skill modifier (or half the pilot’s Wisdom modifier) to the ship’s base saving throw. A ship is immune to most effects that require a Will saving throw (though pilots, crew members, and passengers typically are not).
Once a hit is scored or a saving throw made, multiply by a factor depending on the type of attack used and then subtract the Hardness of the target. Use only one multiplier, the first category of multiplier that applies.
|Attack||Hull or Oars||Rigging|
|Siege engine firing burning or chain shot||x½||x1|
|Fire arrow or bolt||x½||x½|
|Other personal weapon||x½||x0|
|Fire or Acid energy damage||x1||x2|
|Cold, enervation, dessication, positive, or negative energy damage||x½||x½|
All parts of a ship are vulnerable to area attacks. If an area attack has a radius of 15 ft. or more, is a cone of 30 ft. or more, or has a remaining length of line of 30 ft. or more once it reaches the ship, it causes double damage. The same applies to spells that affects 5 or more targets. This doubling is made last, after all other modifications.
Effects and spells that technically cannot affect objects (such as charm person, magic missile, and cloud kill can be used in shipboard combat. Apply their damage to the ship, despite that it really affects the crew. If the effect has no damage normally, assume it does 1d6 per caster level, ignoring Hardness, with a damage cap depending on spell level as normal.
Sneak attack can be used against ships, regardless of range. The rogue aims at a vital component of the target ship and attacks using the lower of his attack bonus and his Disable Device skill. One attempt per round only, and normal range penalties apply.
Indirect fire weapons have a hard time hitting a moving target, such as a ship. There is no accumulation of attack bonus from round to round. Any shot that scatters is considered to miss. Because ships are large oblong targets, reduce the DC of hitting a ship from the fore or arft by 5, as indirect weapons at sea scatter more high and low than to the sides, because of wave action.
Multiple identical weapons firing together are resolved with a single attack roll. This allows the use of the chief gunners attack bonus and feats for the entire salvo. The threat range of the attack is multiplies by the number of weapons in the salvo, but only a single critical threat is scored with each salvo. Critical hits are ignored on salvo fire with non-siege-engine missile weapons.
Fires on Board
Fire attacks to a ship's hull can start fires. Each round's worth of fire arrows and each individual attack by a fire weapon requires the ship to pass a saving throw. The DC is equal to 10 + ½ the fire damage dealt. This is based on damage after Hardness but before multipliers.
A ship on fire takes 2d6 damage each round to the ship's hull, ignoring hardness.
A ship's crew can try and put out a fire, this needs a ship's officer and a fire-fighting party from the crew. A ship with several heroic officers (such as player characters) can make one attempt for each such person not otherwise engaged. This requires a Saving throw with a DC of 25, +1 for each minute the ship has been burning.
- A ship that puts it entire crew on fire-fighting duties, taking no other actions, gains a +10 bonus on this check.
- A dedicated fire-fighting spell (like quench or pyrotechnics gives a bonus of spell level x caster level
- A Water or Cold spell used to fight fires gives a bonus of spell level + caster level.
A ship is either on fire or it is not - multiple fires are not tracked. Once fire on a ship is put out, the ship can be lit again normally, but the difficulty of putting out the fire is back to 25.
Effects of Damage
Ships—and their means of propulsion—are objects, and like any other object, when they take damage in excess of half their hit points, they gain the broken condition.
When a ship or its means of propulsion gains the broken condition, it takes a –2 penalty to AC, on sailing checks, saving throws, and on combat maneuver checks. The ship’s maximum speed is halved and the ship can no longer gain the upper hand until repaired. If the ship is in motion and traveling faster than its new maximum speed, it automatically decelerates to its new maximum speed.
If the hull is broken, half of all siege engines are inoperable (check separately for each). Only half of the ship's complement of missile troops may fire.
A ship whose means of propulsion is reduced to 0 or fewer hit points is immobilized. It can no longer move or take maneuvers. The means of propulsion can be repaired, but to no more than half it's normal hit points and it retains the broken condition until the ship undergoes extensive repairs on shore.
A ship that is reduced to 0 or fewer hit points gains the sinking condition. A sinking ship cannot move or attack. It takes in water causing 1 hp of damage each round (10 per minute). It takes damage normally and can still burn. When the ship reaches a number of negative hit points equal to its full normal hit points, it sinks.
Generally, nonmagical repairs take too long to save a ship from sinking once it begins to go down, but it is not impossible if it sinks slow enough. Magic (such as make whole) can repair a sinking ship. If the ship’s hit points are raised above 0 before it sinks, the ship loses the sinking condition. A ship that has been sinking can be repaired to a maximum of half its hits points until repaired on shore, and the hull retains the broken condition.
A sinking ship will drift at a speed of 5 ft. and can be towed at 30 ft. speed, either to a port or onto a beach. During ship combat, it is considered immobile.
A sinking ship has half its cargo destroyed by water. As the hull is normally used to provide cover for incapacitated crew, the mortality rate among incapacitated crew increases dramatically as well, see Crew below.
A ship that sinks completely drops to the bottom of the body of water and is considered destroyed. A destroyed ship cannot be repaired—it is so significantly damaged it can only be used for scrap material. ¾ of its cargo is lost, as well as any crew still left on board.
For each damage condition a ship suffers, ¼ of its crew are incapacitated. If the hull suffers a damage condition, ¼ of its crew and passengers are incapacitated. A ship that has a section both broken and destroyed (sinking/immobilized) has taken 50% casualties. This has no immediate effect besides the effects of the damage itself, but it depletes the ships crew for future engagements.
How many of these actually die depend a lot on the medical abilities of the ship's officers. At the end of the battle, make a Heal skill check for each incapacitated crew member to save his life. A character capable of casting the stabilize spell can substitute a concentration check for the Heal check. Using healing spells or powers adds a +5 bonus; one spell or power use is required for each such roll, but the decision to use healing can be made after the roll.
The difficulty depends on the damage suffered, and on whether medical attention was provided during the battle or only after the engagement was over. To provide medical attention during ship combat, the healer can provide no other function in the minute after the ship gains a damage condition. Each time the ship suffers a damage condition and no healer does so, the DC increases. Checks are made at the end of the battle.
In general, officers, player characters, and important NPCs are not taken out by random damage like this; it is an attrition on the crew, not a way to kill plot-worthy characters. If no nameless crew members remain to suffer incapacitation or damage, the GM has to decide what happens based on the situation.
|Hull damage "sinking"||+10|
|Each damage step not attended to immediately||+5|
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