Corpen:1889
v. 1.01

v. 1.01 changes: changed hit effects on Very Small vessels.

Introduction
Scale
Definitions
Turn Sequence
Movement
Combat

Corpen: 1889 Fleet Database: Statistics for 56 classes of ironclad-era warships from 13 countries, fleet quality ratings, and ship
rating methodology.

Introduction: Corpen:1889 is a set of rules for simulating naval battles in the late 19th century. It was inspired by GDW's excellent Ironclads and Ether Flyers (I&EF) supplement for the Space:1889 role-playing game. It tries to preserve the "flavor" of that era that I&EF conveyed, while at the same time requiring less dice-rolling and record-keeping than I&EF did. It is based upon my earlier Corpen 18 WWII surface naval combat game, with significant alterations which were required to take into account the much different nature of naval combat in the late 19th century. No rules for aerial gunboats are present yet; however, they will be included in version 1.1.

Scale: The game may be played on a hex map or on a tabletop, with each unit of measurement (or a hex, if using a hex grid) representing 400m. Each turn represents about 6 minutes of actual time. Each ship model/counter represents 1 large vessel or 2 torpedo boats.
 
Definitions:

Class:  Admiral TBS     Size:  VL
Movement: 4/3
Protection: 8
Main Battery:   6      Range:  9/4/2    To-hit:  -1/+1/-1
Secondary Battery: 2 B    Range:  5/2/1   To-hit: --/0/-- 
Tertiary Battery:  U3   Range: 2/1/--  To-hit: +3/+3/+3
Torpedoes:    1F, 2L, 2R
Evasion: 0/+1

Class: The name of the head ship in the class, and the type of the ship. In this case, Admiral-class Turret Battleship.
Size: determines the ship's order of movement, turning ability, and ability to brave high seas, and performance during ramming attacks. There are four sizes, Very Large (VL), Large (L), Medium (M), Small (S), and Very Small (VS). "r" indicates the ship is equipped with a ram.
Movement: the first number is the number of movement points the ship can spend in the first movement phase of a turn, the second the number of points the ship has in the second movement phase.
Protection: Ability to withstand damage. If a ship has two Protection values divided by a /, the first rating is used when the ship is fired upon at point-blank or close range, and the second rating when it is fired upon at long range. "w" indicates a wooden-hulled ship. Protection rating with a 'U" indicates an unarmored ship, whereas a protection rating without it indicates an armored ship.
Main Battery: the ship's heaviest guns. Numerical value represents the power of the main battery, VL, L, or H symbols after it indicate very low, low, or high rate of fire. Batteries without rate of fire indicators have Normal rate of fire. B indicates a battery that is mainly arrayed to fire into broadside aspects. "U"-batteries represent weapons with limited ability to pierce armor.
Range: from left to right, long, close, and point-blank range, in hexes or 400m units of measurement.
To-hit: modifier used on the combat table. Numbers represent, from left to right, modifiers used when unit fires into its forward facing (60 degrees), broadside facing (starboard and port 120 degree sectors), or aft facing (60 degrees), respectively. -- indicates the battery may not fire into that arc.
Secondary, Tertiary batteries: lighter-caliber guns.
Torpedoes: number of torpedoes, and their firing arcs F--forward, R: Right Broadside, L: Left Broadside, A: Aft. A parenthesized torpedo number represents reload torpedoes.
Evasion: first number represents relative difficulty of hitting the target with gunfire (Gunfire Evasion), the second with torpedoes (Torpedo Evasion).


Turn Sequence:
First Movement Phase
First Combat Phase
Second Movement Phase
Second Combat Phase

Movement: The first value in the ship's movement allowance represents movement points that can be spent in the first movement phase, while the second value movement points for the second movement phase. Each movement point is equivalent to one unit of measurement/hex. Movement points may not be accumulated from one movement phase to the next, or from one turn to the next.

Ships are moved in the following order: first all Very Large-sized vessels are moved, then Large vessels are moved, then Medium, then Small, and finally Very Small. Within each size category, ships with the lowest number of movement points are moved first, then ships with the next to lowest, and so on, until ships with the highest number of movement points are moved last. For the purpose of speed determination, use the highest speed the ship is capable of at the beginning of turn (i.e., if the ship's maximum speed has been reduced due to damage, use the reduced speed).

Turning: Very Large vessels may make one 60 degree turn (equivalent to one hexside facing change) per movement phase. Large, Medium, and Small vessels may make one turn per hex (400m) moved. Very Small vessels may make two 60-degree turns per hex (400m) moved. Turns do not cost movement points; however, a ship may make additional facing changes (in addition to "free" changes described above) by paying 1 movement point per 60 degree turn.

-- indicates no effect. H and Q indicate movement halved and quartered, respectively. F means units are forbidden to operate in such weather. Modifiers separated by a / indicate number of movement points subtracted from first and second movement phases, respectively.

Stacking: if using a hex grid, at the end of each movement phase a hex may contain no more than one Very Large ship, or two Large or Medium ships, or two pairs of torpedo boats.

Combat: In this phase opposing ships may attack one another with gunfire and torpedoes. Gunfire and torpedo attacks are resolved sequentially, with the highest-quality units firing first (with damage being resolved immediately), and lowest-quality firing last.

Gunnery:
Determine whether the attacking ship is firing through its Bow, Broadside, or Stern facing. Bow and Stern facings are 60 degree arcs, whereas Broadside arcs are 120 degrees each.

Each of the ship's batteries may only fire once per turn. In other words, if a ship's battery engaged an enemy in the first combat phase, it may not fire again in the second combat phase. An exception to that are quick-firing cannon batteries (all weapons with High rate of fire). A ship may fire its High ROF weapons once into every arc once per turn. Moreover, a quick-firing battery may fire twice into the same arc per turn (but only against different targets) with each shot having an additional -3 to-hit modifier. Both shots may be taken in the same combat phase. Batteries with gunnery ratings marked with "B" may fire into both broadsides during the same turn. However, if that same battery fires into forward or aft arcs, it loses this broadside fire benefit.

To select initial column, subtract protection rating of target from gunnery rating of attacker. Note that some batteries have dual ratings divided by /, with one rating for use against unarmored vessels (protection rating of U1 through U7), and the other for use against armored vessels. Some vessels also have a dual Protection rating. In this case, the first rating is used when the vessel is fired upon at Point Blank or Close range, and the second when the vessel is fired upon at Long range.

Unarmored vessels (U protection ratings) are all considered as having protection of 0 if fired upon by batteries with ratings of 1 and higher.

Batteries with gunnery rating of U1-U7 may not attack armored targets, with the exception of U6 batteries which are considered to also have a rating of 1. Ships with armor value of 1 may be attacked by ships with U5 batteries on the -2-3 column. Batteries with both U and noormal gunnery ratings may use either of the ratings when firing.

When a vessel with protection of U1-U7 is fired upon by a battery with a U1-U7 gunnery rating, use the following rules:
If gunnery rating is greater by 1 or 2, equal to or lower than protection rating, determine the difference between ratings and select appropriate column.
If gunnery rating is greater by 3 or more than protection rating, use "+2+3" column, regardless of the difference between ratings.

Numbers without brackets represent the firepower vs. protection differential. Number within brackets are for torpedo attack determination (see below). 

Roll 1D10 and consult the table:
 

Numbers on the CRT represent number of hits suffered by the target. Hits are cumulative from turn to turn, and may not be repaired. Keep track of each ship's hits by using appropriate markers.

Small, Medium, Large, and Very Large vessels:
1 hit: no effect.
2-3 hits represents minor damage, and result in -1 DRM to all subsequent hit rolls.
4-5 hits: significant damage, -2 DRM, speed reduced by 2 movement points or halved, whichever is smaller, negative Evasion ratings halved.
6-7 hits: target is reduced to only 1 movement point, -4 on all to-hit rolls, negative Evasion ratings reduced to zero.
8 hits: the ship is sunk.

Very Small vessels:
1 hit: represents minor damage, and result in -1 DRM to all subsequent hit rolls.
2 hits: significant damage, -2 DRM, speed reduced by 2 movement points or halved, whichever is smaller, negative Evasion ratings halved.
3 hits: target is reduced to only 1 movement point, -4 on all to-hit rolls, negative Evasion ratings reduced to zero.
4 hits: the ship is sunk.

Gunnery modifiers:

Column shifts:

Shift the column on which the attack is being resolved to the left or right, as applicable:
Gunnery rating with * firing at an armored target: 1L
Gunnery rating with ** firing at an armored target: 2L
Long-range fire: 1L
Point-blank fire: 1R

Die-roll modifiers:
Apply to-hit modifiers for the ship's appropriate firing arc, plus applicable modifiers listed below. Modifiers

VLow ROF add target's Gunnery Evasion rating x 3 to the die roll
Low ROF add target's Gunnery Evasion rating x 2 to the die roll
Normal ROF add unmodified Evasion rating to the die roll
High ROF weapons ignore Evasion rating

Ship with protection rating of U6 fired upon by battery with rating of 1-7: -1
Ship with protection rating of U7 fired upon by battery with rating of 1-7: -2

Target is wooden-hulled ("w" in protection rating): +1

Attacker Crew Quality:
Crack +1
Trained 0
Green -1

Target Crew Quality
Crack -1
Trained 0
Green +1

Sea State:

Torpedoes:
Unlike Gunnery, Torpedo attacks may be made during either, or both, combat phases, as long as the vessel has torpedoes and targets within the torpedoes' firing arcs. Torpedo attacks are resolved after all gunnery attacks have been resolved in a given Combat Phase. Designate firing ship, target, and the number of torpedoes to be launched. Only ready-to-fire torpedoes with firing arcs facing the target may be launched. No vessel may launch more than one torpedo per combat phase, with the exception of torpedo boats, which may launch 2 torpedoes per fire phase (since each torpedo boat counter or model represents two actual torpedo boats). Roll for every launched torpedo to determine whether it hits.

Base To-hit number:
Range 0: 6; Range 1: 4; Range 2: 2; Range 3: 0; Range 4+: prohibited

To-hit number modifiers:
Attacker Crew Quality:
Crack +1
Trained 0
Green -1

Target Crew Quality
Crack -1
Trained 0
Green +1

Target torpedo evasion modifier: unchanged

Surprise attack (target at anchor, etc.): +4

Target's Forward or Aft arc of fire facing the shooter: -2

Sea state: gunfire modifiers are halved.

Roll 1D10. If the die roll is equal to or less than the to-hit roll, torpedo scores a hit. After resolving torpedo hits, roll for damage for every torpedo that struck its target. Roll on the "+7 or more" column to determine how much damage each torpedo has caused. Only Target Crew Quality modifiers are applied:
Crack -1
Trained 0
Green +1

Ramming:
Vessels may attempt ramming, whether they are or are not equipped with a ram (ships equipped with a ram have an "r" in their Size rating). In order to attempt ramming, the ship must be able to enter the same location as the target ship. Attacker and target roll 1D6, add their Torpedo Evasion values, and Crew Quality modifiers:
Crack -1
Trained 0
Green +1
If the attacking vessel has a lower number than the target, ramming attempt succeeds. If it is equal to or greater than the target's, it fails.
To determine damage, roll on the "+7 or more" column, and apply the following modifiers:
Rammed ship the same Size as the rammer: 0
Rammed ship lower Size than the rammer: +2 per size difference.
Rammed ship higher Size than the rammer: -2 per size difference
Rammed ship's Crew Quality:
Crack -1
Trained 0
Green +1

Ships equipped with a ram do not suffer damage due to ramming attempts. Ships not equipped with a ram must roll on the "+1" column, using the same modifiers as the rammed ship. If the ramming ship is equipped with a spar torpedo, if the ramming attempt succeeds damage is resolved as for torpedo attack.

Corpen: 1889 Fleet Database: Statistics for 56 classes of ironclad-era warships from 13 countries, fleet quality ratings, and ship
rating methodology.

Mike J.
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