NEW OPTIONAL RULES FOR SOPAC
by
Alan R. Arvold
The following variant rules are for the game SOPAC. Most
players will recognize them from the Great War At Sea series of
games. I have transcribed these rules to SOPAC and modified them
to take into account the differences of fleet operations in the
Second World War as compared to the First. Also there is a piece
of errata at the end of this article which I missed in my
previous errata article. These rules and errata should be
considered to be unofficial.
16.0 Submarines
16.6 Submarine Aces
Some scenarios direct that a side may have a certain number of
submarines that are captained by skilled and energetic
commanders. The player must designate on the Ship Data sheet
which of his submarines have the ace commanders. Submarines with
ace commanders have a -1 die roll modifier against ASW attacks
made against them. They also have a +1 die roll modifier for
attacks that they make against ships. These modifiers are in
addition to those on the appropriate tables.
19.0 Mine Warfare
Minefields may be placed along Zone boundaries. Some are placed
at the beginning the scenario (see scenario instructions); others
may be sown during the course of play.
19.1 Minefield Location
Note minefields on the Log Sheet (using Log Sheets from the Great
War at Sea series of games) writing down the two zones bordering
the minefield. A player is not required to inform his opponent of
the location.
Example: The Allied player places a minefield west of Savo
Island. On his log sheet under the "Minefields" column he writes
"L21/L22".
19.2 Entering a Minefield
When an enemy fleet marker crosses a mined sea zone boundary, the
player who placed the mines informs his opponent. The Player who
moved the fleet stops moving it and for each ship in the fleet
rolls two dice and consults the Minefield Table listed below.
Minefield Table
Ship is damaged on a result of 11+.
Modifiers:
+1 for each additional minefield (maximum of +5)
+2 for ship moving speed 2 or greater during turn's Naval
Movement Phase
19.21 Procedure: Resolve each mine hit by rolling one die and
consulting the Mine Damage Table listed below.
Minefield Damage Table
Die Roll Damage
1-2 1 Hull
3 2 Hull
4 3 Hull, lose one speed level
5 5 Hull, dead in the water
6 Ship sinks
19.22 Friendly Fire: Minefields do not effect fleets or flotillas
belonging to the player who placed them.
19.23 Mines in Combat: Ships which crossed a sea zone boundary as
a result of leaving the tactical map (6.46) also must have
possible mine hits resolved.
19.24 Submarine Flotillas: Due to their hidden nature on the
Operation Board, submarines are only effected by mines if they
make an attack against enemy ships in a sea zone which contains a
minefield on one or more of its boundaries. After all sub attacks
in the sea zone have been resolved, the enemy player who owns the
minefields announces that there are mines in the sea zone. The
player with the subs randomly picks on of his surviving subs
which is the recipient of the minefield attack. The enemy player
rolls on the Minefield Table with two dice. An 11 or 12 means
that the submarine hit a mine and is now sunk. There are no
modifers. Any other result means that the sub made it through the
field unscathed. In either case the enemy player must reveal the
location of one minefield in that sea zone to the other player.
(Okay it's abstract but it works.)
19.25 MBT Flotillas: MBTs are not effected by minefields.
(Due to their small size and and very shallow draft, MBTs of this
war usually were able to pass through minefields with no problem.
Only those mines which were on the surface were the only real
threat to the MBTs and most of the time the boats moving through
the field at a slow speed could avoid them. Granted there were
occasional MBTs lost to mines but these were usually due to cases
of stupidity.)
19.26 Aftermath: After the player moving his or her fleet has
resolved possible mine hits for one-fourth of the ships in the
fleet (round any fractions up), he or she may stop moving the
fleet and re-plot its movement for this turn and the following
turns (unless the fleet crossed the boundary when leaving the
tactical map).
19.3 Laying Mines
Ships capable of laying mines are noted in the scenario
instructions. Note that a ship's minelaying capability may not be
the same in every scenario.
19.31 Mission Statement: To place a minefield, a ship must be
part of a fleet with a minelaying or a raid mission and must
remain in the sea zone for four turns. Note "mine" on the log
sheet for those turns. If the ship does not move, fire (including
bombardment and anti-aircraft fire against attacking planes) or
suffer damage during those turns, the player may note one of that
sea zone's six boundaries as containing one minefield. The
minefield does not become active (effect passing enemy ships)
until the next turn.
19.32 Extent: All of a sea zone's boundaries may be mined.
19.33 Extra Mines: Additional minefields may be placed along a
boundary already containing a minefield.
19.34 Prohibitions: Minefields may be placed in any sea zone
within two sea zones of a sea zone that contains land (not an
island). Count the sea zone that the minefield occupies, but not
the sea zone the land occupies to determine the distance. An
island is land that is present in only one sea zone. All other
land is coastal.
Note: Although all of the land on the board are islands in the
geographic sense, in game terms they are classified as coastal.
For the record the only island sea zones on the board are as
follows: K9, K26, K27, L12, M33, N32, O31, P13, and P14. Sea zone
U32 (Espiritu Santo) is considered to be coastal. Note that some
of these islands are within range of other coastal sea zones and
thus can be mined.
19.35 Activation: A player placing a minefield may delay its
activation. Note the game-turn (any turn after that during which
it was placed) on which it becomes active. An inactive minefield
has no effect on enemy ships.
19.36 Infiltration: Minefields may be placed along the boundaries
of a sea zone containing a major base.
19.4 Minelayers in Combat
When a minelayer (or another ship acting as minelayer) is hit by
gunfire, bombs, or torpedoes in combat, the owning player rolls
one die. On a result of 6, the minelayer explodes and sinks.
19.41 Panic: A player may order a minelayer (or another ship
acting as a minelayer) to jettison its mines; its fleet mission
must be changed to abort and it may lay no more minefields in the
current scenario but is not subject to exploding if hit in combat
(except through the usual damage results). A ship may not
jettison mines during combat.
19.42 Definitions: A warship is only considered to be a minelayer
for purposes of this rule if it is on a minelaying mission and
the scenario instructions state that it is capable of laying
mines. Minelayers (type ML) are always subject to this rule.
19.5 Auxiliary Minelayers
Some scenarios direct that merchant ship counters be used to
represent auxiliary minelayers. These may be used as multiple-
ship counters to represent more than one minelayer. Auxiliary
minelayers have all the characteristics of the merchant ship
counter used used to represent them (and may explode in combat).
19.6 Sweeping Mines
A minesweeper may be used to remove minefields. Only minesweepers
and those ships noted in the scenario instructions as capable of
sweeping mines may remove mines.
19.61 Mission Statement: To detect or attempt to remove a
minefield, the minesweeper must be part of a fleet with a Mine
Sweeping mission.
19.62 Detection: Before a minefield may be removed, it must first
be detected (minefields placed by the same side are always
detected; you do not have to detect a minefield to sweep your own
mines). To detect an enemy minefield in a sea zone, the
minesweeper must remain in the sea zone for an entire turn. Note
"detect" on the log sheet for that turn. If the minesweeper does
not move, fire (including bombardment and anti-aircraft fire
against attacking planes), or suffer damage during that turn, the
opposing player must indicate which borders of the sea zone
contain minefields, and how many minefields are present.
19.63 Sweeping: After a minefield is detected, a minesweeper may
attempt to sweep it. The minesweeper must remain in a sea zone
bordering the minefield for two full turns. Note "sweep" on the
log sheet for the turn. If the minesweeper does not move, fire
(including bombardment and anti-aircraft fire against attacking
planes), or suffer damage during those turns, the owning player
rolls one die for each minesweeper attempting to sweep mines at
the conclusion of the second turn. On a result of 1 the
minesweeper is destroyed by exploding mines. On a result of 2 or
3, there is no effect. On a result of 4, 5, or 6 one minefield
(sweeping player's choice) is removed.
20.0 Motor Torpedo Boats
Some scenarios include motor torpedo boats (MTBs). Although they
go by many names (PT Boats, MTBs, S-Boats) they are all MTBs and
follow the same rules.
20.1 MTB Flotillas
Unlike their First World War counterparts MTBs in the Second
World War operated in flotillas. A flotilla represents the MTBs
assigned to patrol a certain sea zone. Each scenario lists the
total number of MTBs in the owning player's starting forces, the
total number of these MTBs that may be sent out on patrol at any
one time, and the ports and/or MTB bases that the MTBs operate
out of during the scenario. A player may have any number of
flotillas in the game, subject to the number of MTBs sent out on
patrol. A flotilla may have a minimum of one MTB and a maximum of
the total number of MTBs sent out on patrol.
20.2 MTB Deployment
Players record each flotilla number, the number of MTBs in each
flotilla, and the sea zone for each on the Log Sheet. No counters
are placed on the Operational Board. A flotilla may be assigned
to any coastal or island sea zone within two hexes of the port or
MTB base from which the MTBs operate from. These zones may be
part of the same or different coast or island. However the patrol
zone may not have a zone of open water between it and the
originating port or base if that zone is the only way to get to
and from the patrol zone. (MTBs were quite capable of crossing
short stretches of open water on their own between coasts and
islands but to cross longer stretches of open sea they needed a
bigger ship to guide them.)
20.21 Night: MBTs are only sent out at night. Therefore at the
beginning of each night turn that comes after a day turn, the
owning player records the location and composition of each of his
MTB flotillas during the Orders Phase of the turn. The MTB
flotillas stay in their designated sea zones until the beginning
of the next day turn in the game. MTBs are not used during day
turns. (Although MTBs performed many different kinds of missions
during both day and night, it is their primary combat mission of
patrol which occured at night which the game SOPAC is depicting
in these rules.)
20.22 Weather: MTBs are only sent out if the weather is Clear,
Cloudy, or Rain. They are not sent out in Squall, Storm, or Gale.
A flotilla may be sent out on a later night turn if during an
earlier night turn it could not go out because of bad weather but
the weather later gets better. If a flotilla is sent out on a
previous night turn and the weather turns worse in a later night
turn, the MTB flotilla is considered to be inactive during the
turns of weather in which they are not allowed out. (They have
retired to nearby cove or harbor somewhere to wait for the bad
weather to pass.)
20.3 Contact
If an enemy fleet moves into an MTB patrol zone, the MTB owning
player rolls one die for each MTB in the flotilla, making contact
on a result of 5 or 6. There are no modifiers. If contact is
made, the enemy player must reveal the identity of all ships
present. (Flotillas tended to keep their boats apart to gain
maximum area coverage when searching and converged only after
contact was made in order to make attacks.)
20.4 MTB Weapons
Each MTB has two torpedo factors in a deck mount and one special
gunnery mount.
20.41 Torpedo Attack: Once contact is made the flotilla's owner
selects a target ship for each MTB present in the flotilla. More
than one MTB may gang up on a single target vessel. The owning
player then rolls the die to see if the flotilla has surprised
the enemy. On a result of 4, 5, or 6 the flotilla has surprised
the enemy and all boats may make a torpedo attack on their
respective target ships. On a result of 2 or 3 the target ships
may fire only at those MTBs which are attacking them. On a result
of 1 every ship in the fleet may fire at the MTBs.
A ship may only fire its tertiary and AA guns at MTBs, but hit on
a die roll of six (there are no modifiers). An MTB is destroyed
by any hit. Any MTBs which survive the enemy fire may then make
torpedo attacks on their respective target ships. (Due to the
MTB's small size and high speed, warships would only engage them
with their quick firing tertiary guns and AA batteries. They
would not waste rounds from bigger guns nor torpedoes on such
small prey due to the extremely small chance of getting a hit.)
An MTB makes a torpedo attack with all torpedo factors (even
American MTBs before September 1943). A hit is scored on the
target on a die roll of 6, there are no modifiers except for
Aces. (MTBs of the period had rudementary aiming sights for their
torpedoes and had to get in close in order to make an attack,
hence the reason for no modifiers except for Aces.)
20.42 Special Gunnery Attacks: After resolving all torpedo
attacks, the surviving MTBs may at the owning player's option
execute a special gunnery attack on their respective target
ships. If the owning player does not want to make special gunnery
attacks then the MTB attack is over at this point. Those MTBs
whose target ship has sunk may make no special gunnery attacks.
For each surviving attacking MTB roll one die, a result of 6 is a
hit. For each hit roll two dice and consult the Gunnery Damage
Table for effect. Hull and Critical hits are considered to be No
Effect. MTB gunnery can only effect those gun boxes and torpedo
mounts that have no armor. MTB gunnery attacks can not use the
Secondary Penetration rule. (MTBs were armed with machine guns
and Anti-Aircraft weapons and knocked out weapon systems on
warships by causing casualties among the exposed gun and torpedo
crews, not by damaging equipment.)
Should an owning MTB player opt to make special gunnery attacks
on the target ships with his MTBs then every ship in the enemy
fleet may fire their tertiary and AA guns at the surviving MTBs
upon completion of the owning player's special gunnery attacks.
This is regardless of what the owning player rolled when contact
was first made. After all enemy ships have fired, including those
who have fired again, and the results resolved then the MTB
attack is over.
20.5 Ace MTBs
A certain number of MTBs in a scenario may be designated as Ace
MTBs. When a player deploys his MTBs out on patrol he records the
number of Ace MTBs in each flotilla that he sends out. When an
MTB attack is made Ace MTBs add one to the die roll for torpedo
attacks made by their particular boats. When enemy ships fire at
attacking MTBs they can not designate that they are firing at Ace
MTBs only. Instead the total number of sunk MTBs attacking a
particular target ship is tabulated and then randomly distributed
between the Ace and non-Ace MTBs attacking that ship. The same
applies to enemy fleet fire against MTBs during special gunnery
attacks. Ace MTBs have no other effect.
20.6 Restrictions
MTBs may not conduct ASW attacks against submarines or be
attacked by them either. (Yes MTBs did carry a few depth charges
but they were not a proper ASW ship. On several occasions during
the war MTBs did sink submarines, usually with torpedoes, but
these were usually the result of chance encounters and not as
part of deliberate ASW operations.)
MTBs may not attack or be attacked by enemy MTBs. (Okay there
were battles between opposing flotillas of MTBs, especially in
the Atlantic and in the Mediteranian, during the war. However
given the operational level of the game these battles are not
that significant and so are not portrayed.)
20.7 MTB Bases
Besides operating out of major and minor ports, MTBs also
operated out of advanced MTB bases that could be constructed
quickly on recently captured islands. While these bases did serve
as ports for MTBs to be based at, they were also more vulnerable
to shore bombardment and air attack as well.
20.71 Shore Bombardment: MTB bases may be the target of an enemy
shore bombardment. The enemy player merely follows the normal
rules (Rule 9.1) for shore bombardment. However if MTB base is in
a sea zone with other bases as well (i.e. airbases), then the
enemy fleet with the bombardment mission for that sea zone must
have designated on the plot sheet which base it is to bombard for
the mission. An MTB base which has been bombarded may not serve
as a port for MTBs for the remainder of the scenario. However if
the bombardment occurs at night while MTBs assigned to the base
are out on patrol, those MTBs remain out on patrol until the next
day light turn, after which they may not be used for the rest of
the scenario.
20.72 Air Attacks: Air strikes may be conducted against MTB
bases. These follow the rules for Land Strikes (Rule 13.5). An
MTB base has an AA value of 8. It takes four hits to knock out an
MTB base. Hits may be accumulated from multiple air strikes over
the course of a scenario. An MTBs may operate out of a damaged
MTB base until the fourth hit from an airstrike has been scored,
after which they may not be used for the rest of the scenario.
20.73 Base Repair: MTB bases may not be repaired during the
course of a scenario. (Repair materials and supplies usually had
to be brought in by ship and then it took time to put the base
back together, which is usually beyond the time period of most if
not all scenarios in the game.)
Scenario Book
Operational Scenario #7
Add to Allied Forces:
At MTB Base on Tulagi Island (L23)
4 MTBs of which 2 may go out on patrol per night.
Operational Scenario #8
Add to Allied Forces:
At MTB Base on Tugali Island (L23)
8 MTBs of which 4 may go out on patrol per night.
Operational Scenario #9
Add to Allied Forces:
At MTB Base on Tulagi Island (L23)
8 MTBs of which 4 may go out on patrol per night.
Operational Scenario #10
Add to Allied Forces:
At MTB Base on Tulagi Island (L23)
8 MTBs of which 4 may go out on patrol per night.
Errata
American Capital Ship Hit Record Sheet
The Australian heavy cruisers Australia and Canberra should each
have a Torpedo Factor of 2. They each should have a point value
of 24.
(Both ships still had their torpedo tubes mounted in 1942. The
Australia had hers removed in 1943 during a refit and the
Canberra undoubtedly would have had hers removed as well if she
had not been sunk. Besides, underwater photographs of the wreck
of the Canberra clearly show that not only did she still have her
torpedo tubes mounted on the ship but that she also fired her
starboard torpedo tubes during the battle of Savo Island where
she went down.)