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Optional Rules

These additional rules may help to add some historical realism to regular Battlefleet games. Because these are not part of the main rules, players should make sure that all participants know which optional rules (if any) are being used. Immediately below is a short list of optional rules grouped by general effect. Some of these rules have not been playtested as extensively as others. If you notice any odd effects, feel free to email us with your observations.
  • Most common advanced options: 404, 502
  • Rules that simplify the game: 102, 405
  • Night fighting rules: 201, 301, 305, 402
  • Rules that adjust for variety of vessel types: 401, 501

101 - Crack Crew Members
Players may roll at the start of a game to see if a ship has any crew members who are especially gifted or popular (or both). Roll 2D6 for each ship. A result of 11 or 12 will allow one more roll (players may roll two different colored dice at once to save time) with the results below indicating what type of special person is on that vessel. Players who want to increase the number of crack crew members may broaden the acquisition die roll to something like 10-12 or 9-12. Record the existence of the special crew member in one of the several blank areas of the ship's log left for this purpose.

12 = Dynamic Captain: +1 on all command and DC rolls. Killed by: 1D6 die result of 6 after any CT critical hit.
9-11 = Ingenious Engineer: +2 on all DC rolls for P hits, -1 on all sink rolls. Killed by: 1D6 die result of 5,6 after any iE critical hit.
6-8 = Aggressive gunnery officer: Double danger zones for this ship. Killed by: Any BRx hit.
3-5 = Smart magazine master: +2 on all M hit critical effects rolls. Killed by: 1D6 die result of 6 after any iM critical hit.
2 = Popular crewman: +2 on all DC rolls for S and T hits. Killed by: Secondary or Tertiary hit results on the De table.

102 - Simplified Gun Patterns
There are three basic types of broadside weapon patterns: 0, 1 and 2. Types 1 and 2 require a bit more die rolling and tracking during game play in order to establish which hits go to which weapons within each group. In return players enjoy somewhat more accurate angles of fire for those specific positions. Players who don't want to worry about the details and differences between the three distribution types may simply use all beam patterns as type 0. This will often simplify game play at comparatively little cost in technical accuracy.

103 - Seaways
The seaway ratings posted on the ship data sheets allow players to reflect the effects of the ocean's stormy nature on a vessel's performance, or even its ability to be at a battle in the first place. Bad weather could keep light vessels harbor bound for days at a time. The charts below relate some possible weather conditions to the seaway ratings posted in the rules

For players doing a common hypothetical battle which is not within a campaign context, the Rolling for Seaway chart below can help throw some alternative weather into game play. Note that the location listings are casual recommendations only. Players may wish to use different values based on knowledge they have of individual areas.

Rolling for Seaway (Roll 2D6)
Location Die Roll Result*
2 - 10 11 12
Mild region, Unprotected
(Antilles, South China Sea, Caribbean, Coastal Mediterranean, Red Sea)
n/e n/e Choppy
Mild region, Protected
(Java Sea, Malacca Straits, Dardanelles
n/e n/e n/e
Moderate region, Unprotected
(Baltic Sea, Open Mediterranean, Black Sea, South Atlantic, Western Indian Ocean)
n/e Choppy Rough
Moderate region, Protected
(Skagerak, Yellow Sea, Adriatic, Agean, Hawaii)
n/e n/e Rough
Severe region, Unprotected
(North Atlantic, Cape Horn, North Pacific)
Stormy Rough Stormy
Severe region, Protected
(English Channel, North Sea, Skagerak)
Choppy Rough Stormy

Seaway Effects
Sea Condition*
Choppy (½) Rough (1) Stormy (2)
27+ - - Distracted
17 - 26 - Distracted Impaired
8 - 16 Distracted Impaired Degraded
4 - 7 Impaired Degraded Paralyzed
1 - 3 Degraded Paralyzed Paralyzed
Modifier: Move one effect column to the right if vessel has poor seaway rating.

Distracted = Boat guns halve ROF. All guns halve danger zone.
Impaired = Weapons under 16cm halve ROF. No danger zone. Reduce available speed by one propulsion box.
Degraded = No weapons under 16cm (6.1") may fire. Weapons 17cm and larger are halved ROF, may not fire at long range. No danger zone. Reduce available speed by half.
Paralyzed = No weapons may fire at all. Ship's speed is for bottom propulsion box only.
Note: No torpedoes may be fired in stormy seas.

* The number after each sea condition is its attack value for flooding. During the second step of each damage phase, every vessel which can be "attacked" by the sea on the 25> or higher Flood Occurrence column must test for flooding, along with all other corresponding die rolls which accompany such rolls and results.

Example: A destroyer with a size of 1 operating in rough seas must roll for Flooding on the 100> Flooding Occurrence column. A small unarmored cruiser with a size of 8 operating in stormy seas must roll for Flooding on the 25> Flooding Occurrence column.

201 - Night Fighting: Command
Considering a scenario to be taking place at night creates a number of difficulties for both players. The following night fighting rule is to cover the command aspects of night combat.

During night time turns, all players must record movement and speed three turns in advance for each division or individual ship (a ship not part of any other division). This time lag may be reduced to the normal one turn in advance for every vessel that has one of its undamaged searchlights turned on from the previous turn's movement phase. One ship following the illuminating vessel as part of a line ahead formation may move along with the lead vessel, benefitting from the time lag reduction. Because of this, players moving at night may want to use two-ship divisions.

202 - Radios & Wireless
During the Russo-Japanese War, the Japanese Navy had a policy of unplugging their radio sets and stowing them below the armored deck for protection. Players wanting to re-create this condition will not allow Japanese vessels to conduct any radio communications during pitched battles, although it should be remembered that they did keep their radios operational during blockade and patrol duties. Any moderate actions occurring as a result of such patrols might well see Japanese ships fighting with operational radio sets.

Searchlight Hint

Try using the plastic tubes used to make cotton swabs. Just clip off the cotton wound onto either end and you are left with a small white tube of plastic just the right length for a 1/3000 scale ship model's searchlight beam.
301 - Night Fighting: Movement
Considering a scenario to be taking place at night creates a number of difficulties for both players. The following night fighting rule is to cover the Movement aspects of night combat.

At the end of each movement step, players must declare whether any ships are using their searchlights. Each searchlight (represented by an LT box on the ship log) may conduct either of two functions: 1) Aid command and movement by reducing the command time lag. 2) illuminate enemy vessels. Use short sticks to indicate the direction of each light function, remembering that if a player wants to use one light function for purposes of reducing the command time lag, one light stick must be pointed straight off the end of the bow. The searchlight capable of doing this is always the first LT box on the ship log. If that box is damaged or destroyed, the ship may not use its searchlights to reduce the command time lag. A searchlight "stick" will illuminate any enemy vessel at which it points out to a distance of one range bracket. This means that a vessel with two operational LT boxes may illuminate up to three enemy vessels while reducing it's command lag, or it may illuminate up to four enemy vessels without reducing its command lag.

A vessel using any of its searchlights is considered visible to all enemy vessels within two range brackets. Friendly vessels in the vicinity of a ship using searchlights are still considered to be invisible unless they are between the spotting ship and illuminating vessels and within one cable distance of the searchlight beam.

Optional searchlight rules: In order to prevent excessively efficient coordination of searchlights among several ships, players may enforce a 1D6 die roll to turn any one searchlight on or off, keeping in mind that each searchlight is good for two functions. Using this rule, a die roll of 4-6 will turn on or off any searchlight. Another variation on this theme is for the searchlight die roll to be a 5,6 if the intended target of the illumination is a vessel of size 2 or smaller. In this case, players must declare the intended use of their searchlights before rolling for them.

302 - Breakdowns
For fleets with a poor maintenance record, players can reproduce one of the more common mechanical defects by rolling two six sided dice (2D6) for each ship which attempts to change its speed. Apply the following unmodified results:
12 = Engine breakdown. Ships loses all propulsion until repaired on a die roll of 5,6
11 = Engine malfunction. Ship may only use half available speed until repaired on a die roll of 4-6
1 - 10 = Minor defect, ship not affected.

303 - Battle Speeds
Most fleets of this period had specific battle speeds assigned for each division of ships based on their fastest reasonable cruising speed. Rarely did a group of battleships tear along at maximum speed, even during battle. Usually the difference between the assigned battle speed and the maximum available speed of a division was referred to as its speed reserve and was only used in emergencies.
Players wanting to re-create the use of battle speeds will assign just two or three speed categories as being available to any one division: slow, half-speed and fast. The fast category should be about 85% of the average maximum speed for that division, and slow should be about 30%. Half speed should about 55% of a division's average maximum. When issuing movement orders, the ships will be given these speed orders. Ships will always attempt to keep the most recent speed order until issued new speed orders. Vessels unable to maintain speed must drop out of line if the division commander does not issue new speed orders.

304 - Mistaken Evolutions
Many fleets of this period lacked extensive training for moving in division and fleet groups. It took a lot of experience to move three or four 12,000 ton ships in unison and have them all go in the same direction at the same time. Fleets considered to have less than stellar training in this regard can suffer the following optional game effects during movement:

Whenever a division of four or more vessels is moving as a unit (line ahead or abreast) and a turn of 90 degrees or greater is ordered, roll for each vessel other than the flagship of that division before executing the movement. On a 1D6 roll of 6 the vessel in question will use the turn mode opposite of that for the turn. I.E. - a ship ordered to turn in succession will turn as it would for a simultaneous turn, and a ship ordered to make a simultaneous turn will move as if to turn in succession. Any vessel doing this will also cause the next ship behind it (unless that vessel is the flagship) to move the same way on a die roll of 5 or 6.

305 - Collisions
Contrary to perceptions about this period, ramming was not part of military doctrine and had not been for many years. Even by 1885, the increasing dominance of the torpedo and long range gunfire spelled doom to the ramming craze which had previously swept naval circles. For the Battlefleet 1900 period, only accidental collisions have been considered, although players who still wish to ram can certainly attempt to place their vessel in a situation in which it may collide with an enemy, but the odds are not so good that they will succeed. There were only a very few times during this era that captains tried to ram. They were always under desperate circumstances, and by all appearances they usually decided the better of their effort before fully closing on the enemy. It didn't really work.

For game play, the possibility of collision arises when two vessels end their movement turn with any portion of their bases overlapping, or encounter a situation during the mutual move sequence in which their two bases obviously overlapped. Any situation in which it is not obvious that bases would have definitely overlapped is not a viable collision condition (player's discretion obviously comes into play here). For each collision course situation, roll two six sided die (2D6) and consult the chart below. Modified die results which fall within the number ranges listed will result in a collision. If a collision occurs, compare the sizes of the respective vessels in the same manner as that used for calculating Flooding Occurrence (see Combat Chart).

Example: Two armored cruisers each moving at 18 knots have their bases overlap during movement. They are both medium sized ships, and so the difference between their turning circles is zero (the Turn Differential compares/contrasts the two turning abilities of the two vessels). They are both moving the same speed, so their speed differential is in the 0 - 5 category (if one ship is moving at 10 knots and another at 22, their speed differential would be 12 knots). This means that they will collide on a modified die roll of 8 through 12, which is the highest chance of collision.

If a collision results, each ship rolls on the Flooding Occurrence chart for damage. In this case, if one ship were size 20, and the other a size 30, it would mean that the size 30 vessel would roll for damage on the 50> column, because the colliding vessel is 50% or greater in comparative size. The size 20 vessel would roll for damage on the 150> column, because the colliding vessel is 150% or greater in comparative size to it. In case of actual flooding, a vessel must also roll on the Flooding Effects section, just like in the rest of the rules.
Collision Chart (Roll 2D6)  
Speed Differential Turn Differential
0 1 2+
0 - 5 knots 8 - 12 9-12 10-12
6 - 12 knots 9 - 12 10-12 11,12
13 knots + 10-12 11,12 12
Collision Die Roll Modifiers:
One side is attempting to ram: +1
Both sides attempting to ram: +3

401 - Adjusting ROF
Battlefleet 1900 is calibrated for battles between capital ships circa 1900. A battle mainly featuring older ships with lower rates of fire will move too slowly if those vessels are main participants, and it will move too quickly if all new light vessels are used. When conducting such battles, the rates of fire may be adjusted to maintain a desired combat tempo. When to do this should be unanimously agreed upon by players, as it can have a profound impact on play if too many new high-ROF vessels are present amongst much older vessels (Such extreme conditions did happen in real-life during the Sino-Japanese War).
Rates of Fire Adjustments
Original ROF ROF based on dominant type*
1/8 1/4 1/2 1 2
2 6 5 4 2 1
1 4 3 2 1 1/2
1/2 3 2 1 1/2 1/4
1/4 2 1 1/2 1/4 1/6
1/8 1 1/2 1/4 1/8 1/10
* Note that the "1" column is the game's default ROF setting, included here for reference.

402 - Night Fighting: Gunnery
Considering a scenario to be taking place at night creates a number of difficulties for both players. The following night fighting rule is to cover the Gunnery aspects of night combat.

Ships may only fire at enemy vessels that are considered to be spotted. A ship is considered spotted if it is illuminated by searchlights, or itself is using its searchlights. A vessel is also spotted for the current turn if it has external fires or it passes between any ship with an external fire and an enemy vessel. For game play purposes, all vessels are considered able to recognize the silhouettes of all other vessels, and may therefore fire upon those which are spotted with the aid of any similar backlighting such as searchlight beams or fires (see Night Fighting - Movement rules above).

Vessels illuminating with their searchlights will suffer LT hits on any De/Upperworks die results of 1 through 3. A destroyer within one cable distance of a lit searchlight will score an LT hit with its boat guns (if any are in service) on a 1D6 roll result of 6. This must be declared and attempted at the start of turn step three. A destroyer firing on searchlights may not conduct any other fire during that turn.

Extra optional rules: Players may establish a maximum visibility level by rolling 1D6, which can represent an ambient spotting distance in cables (one cable = 1/10 of a nautical mile). This would be in addition to any above spotting rules.

403 - Concentrating Fire
Ships which fire on a vessel already being fired upon by the same caliber from other vessels may not roll for "bonus doubles" hits. This represents the problems spotting fire correctly amongst friendly vessel's shell fire.

404 - Bonus Hits
If a player rolls doubles within a set of damaging Vitals die rolls for AP fire, an extra hit on the Vitals section of the General Damage Table is rolled for. Each additional identical number per set adds one to the total. I.E. - three of the same penetrating number will result in two General Damage rolls, etc. Bonus rolls resulting from non-penetrating vital hits (50 percent category) are considered De hits. Bonus rolls resulting from penetrating vital hits (the 100 percent category or greater) are considered Di hits. Upperworks hits by AP do not qualify for bonus hits.

If a player rolls doubles within a set of damaging Upperworks die rolls for HE fire, one external F hit (fire) is immediately added to the vessel's ship log. Each additional identical number per set adds one to the total. I.E. - three of the same penetrating number will result in two F hits, etc. Vitals hits by HE do not qualify for bonus hits.

405 - Die Based Shell Hits 1
For those players who prefer to use dice instead of range guessing to decide shell hits, simply change the basis for rolling Upperworks and Vitals hit dice from the number of rounds in the target zone (which is done after guessing the ranges). Instead, roll one hit die for each four gun tubes fired at long range, each two gun tubes fired at medium range and each gun tube fired at close range. No effective fire is allowed at extreme range (four range brackets) using this rule.

An extra possible option to this rule is allowing the fire of different ships to be combined if they are firing onto the same target. For example; two battleships, each with one main turret damaged, may combine their remaining one turret each to qualify for one long rang die roll. Players may want to enforce a "coordination" die roll of 5 or 6 for this to occur.

406 - Die Based Shell Hits 2
The previous method for die-based gunnery gives obvious advantages to vessels with numerous guns. An alternative to this is the use of different hit dice for each range bracket. Continue using the standard combat chart, but only use six sided dice when firing at targets within the first range bracket. Even four sided die could be used at that range to increase the rate of hits. For firing at targets within the second range bracket use eight or ten sided dice and in the third range bracket use twelve sided dice. Players may carry this further by using twenty-sided dice at very long range in the fourth bracket.

For example: A battleship with four 30cm guns is firing at a ship that is in the third range bracket. Instead of guessing the range, the player rolls four twelve-sided dice, with each 1 result on the dice scoring a Vitals hit, and each 2 on the dice scoring Upperworks hits. All other die results are considered misses. If firing at a target within the closest range bracket, the battleship would simply use four or six sided dice. Players may also use the fast play combat chart in conjunction with this optional rule. Below is a chart showing a selection of some possible "die selection curves," each of which gives a slightly different hit profile.
Die Based Shell Hits 2  
Type Range Bracket  
Short Medium Long V.Long
Simple 6 6 12 n/a
Simple-Fast 6 6 8 12
Common 4 6 12 n/a
Fast Play 4 6 8 12
Advanced 4 6 12 20
Values in field are dice type (six sided, eight sided, etc.) to be used within that range bracket

407 - Expanded danger zones
For players who like guessing ranges but would prefer to have an easier way to score hits, try expanding the danger zones. For targets within the first range bracket, make the danger zone one full range bracket. For targets within the second range bracket, make the danger zone one-half of a range bracket. For targets within the third range bracket, make the danger zone one-quarter of a range bracket. This will dramatically increase the scoring of hit zones. Coupled with the Fast Play combat chart, the expanded danger zone rule will create a "hyper-play" mode for extra-fast play.


501 - Flooding: Light Vessel Actions
When using all light vessels in a battle, the flood protection modifier curve on the Flooding chart can be flattened out a bit by using -1, +1 and +2 instead of -2, +2 and +4 for flooding checks. In the absence of heavily armored units this helps to prevent a sudden death environment for lighter weight vessels (the combat chart is geared to the presence of heavily armored warships).

502 - Thin Barbette Shields
Some vessels had unusually thin barbette shields which were not factored in to the final vitals value in order to prevent the very real protection offered by the barbettes from being unnaturally reduced through averaging. Players who wish to include the vulnerabilities of thin barbette shields - or no shields at all - into the game should include a +1 die roll modifier for the De Vitals hit, which covers non-penetrating AP striking a ship's vital armor area (Note that this will reduce the existing AP minus from a -2 to a -1). This Thin Shields modifier will make it slightly more likely that an AP round striking under that circumstance will damage a main gun position. A tentative list of ships which could be considered to have thin barbette shields would include: Japan: Fuji (?), Chin yen, Hashidate, Matsushima, Sai Yen. ES: Maria Teresa, Pelayo. US: Maine (i), Texas. CN: Chi Yuan, Chen Yuen, Ping Yuen, King Yuen. UK: Royal Sovereign. DE: Brandenburg. IT: Sardegnia, Andrea Doria, Italia.

503 - Japanese Ammunition
The shimose based ammunition used by Japan circa 1904-1905 were based on a class of explosives similar to Lyddite. However, there still seems to be some more research necessary to clarify what precisely they did with existing ammunition designs as well as their own designs. It is known that the Japanese used both shimose filled armor piercing (AP) and black powder filled AP ammunition purchased from Great Britain. As if this did not complicate matters enough, the Japanese used shimose in both their AP and HE ammunition. Because of the inherently volatile nature of shimose, shimose effectively turned Japanese AP rounds into HE rounds or SAP (semi-armor piercing) ammunition, and it turned their HE shells into hyper-sensitive explosives that were probably not even bore-safe (not safe to be fired in a ship's cannon). This last item was probably the cause of several damaging turret accidents on board Japanese ships, although the Japanese claimed they were caused by overheated guns.

For game play in Battlefleet 1900, players may re-create the use of shimose based ammunition by having all Japanese AP hits behave as normal HE ammunition, and all Japanese HE move one column to the right for Upperworks HE hits and one column to the left for Vitals HE hits. Each fire hit caused by any Japanese shimose based ammo triggers two fires instead of one.

As an additional factor, players may either allow each Japanese ship to "choose" whether it is firing shimose based AP or black powder based AP, or have that matter decided by a die roll. This could end up being more trouble than it's worth, but nevertheless remains a possible option.

504 - Russian Ammunition
The Russian Navy during this period apparently used armor piercing ammunition (AP) which had an unusually small bursting charge. Combined with the already light weight of the shells, this resulted in less than favorable performance. Players can re-create the effects of Russian AP by not allowing any AP penetration hits to destroy (Mx or Px) any positions. All corresponding hits will instead become standard damage (M or P).

505 - Tertiary Hits
Tertiary hits on vessels which have no tertiaries will usually result in no hit scored. Players may instead have a chance of each T hit become an S or De hit instead. For each T hit scored on a vessel which has no tertiary weapons, roll 1D6. A result of 5 results in an S hit, and 6 results in one De hit.

506 - Post-game Saving Rolls
At the end of a battle, a vessel which is suffering from five or more points of flooding events may roll two six sided dice (2D6) on the chart below to establish whether it was lost at sea before reaching a safe anchorage. Cross index the total end of game flooding points for the vessel with the distance to the closest harbor to acquire the modified die roll range which results in a loss. Players will of course need to decide how great a distance lies between their vessels and the closest harbor.

Lost at Sea Test (Roll 2D6)
Flooding Points Closest Friendly Harbor
1 - 10km 11 - 50km 60km+
5, 6 12 12 11, 12
7, 8 11, 12 10 - 12 9 - 12
9, 10 10 - 12 8 - 12 5 - 12
11, 12 9 - 12 6 - 12 3 - 12
13+ 5 - 12 3 - 12 2 - 12
Die Roll Modifiers:
Each fire burning = +1
Each damage control die lost = +1
Each point of uneven flooding = +1
Rough seas = +2
Stormy seas = +4

507 - Seawater Fire Fighting
Whenever a vessel suffers heavy flooding or greater in any of its compartments, the controlling player may roll 1D6 against any one internal fire if any are present. On a die roll of 5 or 6, one internal fire is put out. This may happen a maximum of once per turn, and only at the time the corresponding FL hit is inflicted.

508 - Spanish Ammunition
Due to government inefficiency and corruption, the Spanish Navy during this period maintained an erratic supply of ammunition, some of which was good quality and some of which was not. Players can re-create the effects of the erratic ammunition supply by reducing the size and penetration effectiveness of Spanish guns by 20% to 40%, depending on desired handicap. Some Spanish ships were said to have even carried mixed ammo loadouts, and to have fired off their "good ammo" early in an engagement. If this is true, players might want to give each Spanish ship a certain number of firing turns at their full value before reverting to the lower value (1D6 = number of full value firing turns).

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