From Moves#11 CA Adding Simultaneity by Jerrold Thomas "CA" represents a departure from other naval surface combat games. It has much less of the miniatures game in it than do most naval games. Partly because of this, and partly because it does build on existing systems, it plays much more smoothly and rapidly than do most naval tactical games, yet without losing interest and excitement. It's greater simplicity lends itself to two things: 1. "CA" will be provocative of variants because all of the essentials are presented in a remarkably simple, and easily built upon format. 2. The "CA" system can be integrated with land operations without introducing hopeless complexity. The only aspect of the "CA" game-system which I feel could use some improvement is the Torpedo Combat Procedure. Here the abstraction in the CRT becomes a significant deviation from reality. In "P" and "W" gunnery results, a broad range of possible outcomes, from one critical hit to many not-so-critical ones, is abstracted to give a net effect. The obvious premise is that one shell will not sink a ship, but that a range of combinations can have a sum effect on a ship's performance. When, say, two CA's slug it out, both will score some hits, but that does not say that these hits will or will not affect the combat performance of the ship hit. The "CA" Defense Strength, based on ship "protection," is thus a good gauge of a ship's relative resistance to gunfire (in the abstract sense). In torpedo combat, however, such a broad range of results does not exist. Torpedo combat is an "either-or" situation, either a ship is hit, or it is missed. A ship's armor protection has no positive relation to that ship's chances of being hit with a torpedo (in fact it has a negative relation, since more armor means a larger and less maneuverable ship), and has relatively less relation to how a ship will survive a torpedo. As an example, the Yamato has a Defense Strength of 36, the Kagero a Defense Strength of 2. While 1 torpedo would sink the Kagero, the Yamato obviously would not require 18 torpedo hits to be sunk (it actually took 12 hits, but several of these were probably "overkill"). The key parameter in torpedo combat then becomes whether or not the given ship will be hit by an attack. Factors affecting the chances of getting a torpedo hit on a ship were: 1. The torpedo crew's skill in setting torpedo solutions, 2. The relative speed of the torpedoes, 3. The number of torpedoes fired, 4. The range to the target, 5. The relative direction of the target's movement, 6. The velocity of the target's movement. The "CA" Torpedo Strength already makes allowance for factors # 1, 2, and 3; also current "CA" rules clearly take #4 into account. I considered #5 as being included in the current rules for two reasons: 1. Ship facings relative to each other are ignored for gunnery combat, and would be impossible to add without introducing unacceptable complexity. 2. The Attack-Movement Phase order assures that a ship moving away from an attacker will have increased his distance from the attacker prior to the attack, thus lowering the attacker's Strength in many cases. Accordingly, relative vulnerability to torpedo attack, as far as scoring torpedo hits is concerned, becomes dependent on velocity. This is reflect in a new... TORPEDO COMBAT PROCEDURE: 1. Compare the sum of the attacking ships' torpedo strengths to the defending ships Torpedo Evasion Value - TEV (correcting for any range effect on the torpedo strength), to establish a basic odds; round this odds off downward to one of the simplified odds on the CRT. a. A ship's Torpedo Evasion Value - TEV - is equal to its current speed, (taken from its speed/facing marker), plus 1; i.e., a ship DIW has a TEV of 1, a ship moving at speed 5 has a TEV of 6, etc. 2. Roll the die once for each battle against the Combat Results Table - CRT - under the appropriate odds column. The CRT results have the following meanings for torpedo combat: a. a "P" or "W" result indicates one torpedo hit on the defending ship; b. a "PW" result indicates two torpedo hits on the defending ship. 3. If a hit or hits are secured, the die is rolled again, for each battle in which a hit (or hits) was secured, against the Torpedo Hit Chart, cross-indexing the die roll with the number of hits secured and defending ship Defense Strength (from the ship counter). The Torpedo Hit Chart results are the same as those given under the CRT, except for: "2P" indicates that the defending ship receives 2 Power hits; "S" indicates that the defending ship is sunk, and removed from play.
The data on which the Torpedo Hit Charts are based is found, partially, in the Torpedo Hit Results, 1942-43 table. This table was compiled from fifteen actions involving torpedoings, from the Java Sea battle, 2/22/42, to Empress Augusta Bay, 11/2/43; both Allied and Japanese results are shown. The results are expressed in terms of how many ships of each type received a given number of hits in one of the engagements, and what the impact of that number of hits was on the ship in terms of "CA" combat results. In many cases ships were also hit by gunfire, but it is impossible to accurately reflect relative damage contributions.
The table is explained as follows: In the engagements covered, for example, 15 DD's received one torpedo hit; of these, 13 sank in the engagement hit, 1 was DIW, and one suffered damage equal in "CA" terms to a "PW" hit. The table makes several things apparent which are not reflected clearly in the game or article. First, one torpedo hit had a much better than even chance of sinking a DD (85%?). The only two exceptions, Selfridge, and Foote, were both hit on the extreme ends. Foote was hit on the stern, lost it's stern section and screws, and was DIW; Selfridge was hit on the bow, and lost its bow section with two turrets, and could make only about 10 knots. Contrary to the article, Chevalier sank after a single torpedo hit which removed her bow section somewhat further back than in the case of Selfridge. This brings up another aspect of torpedo hits which I have attempted to incorporate. In a significant percentage of these hits, the bow sections of ships up to and including CA's would be blown off, removing the bow turrets and drastically slowing the ship if it was not sunk. The "CA" equivalent of this would be "PW," but this is impossible under the present system. The "PW" results on the Hit Chart also reflect the fact that a ship's fighting power was intimately linked to its motive power the boilers that turned the screws also turned the turrets. SCENARIOS AND SPECIAL RULES Another area of "CA" which can be improved is its reflection of the great changes in American doctrine, training, and technology in the period 1941-45. Also, improvement can be made in reflecting significant, unusual conditions which existed in individual scenarios. Accordingly, the following special rules are proposed: (for scenarios after 8/1/43): 1. USN ships have a primary torpedo range of 4. 2. USN can use FCR (fire control radar) on ships at 10 hex range which are not "spotted." All firing ships must fire at the nearest, or the larger if two are equally close, enemy ship all firing ships are spotted as per "CA" rules. Scenario Special Rules Scenario 2 - Savo Island 1. U.S. Cruisers, once hit, are permanently spotted (this reflects the presence of unprotected fabric spotter planes and gas on deck). 2. Unless IJN ships come within 4 hexes on turn 1, U.S. ships may neither attack nor change course or speed. [Note.. even these additional rules cannot fully simulate the extent of American unpreparedness at this point; the actual battle was a 43-0 Japanese Victory]. 3. The CA-2 (IJN) has a Torpedo Strength of only 20, but may reload twice. Scenario 4 - Guadalcanal 1. USN ships are moving at speed 3 to start. 2, If IJN score over 10 bombardment points, they may extend the scenario to 20 turns. If they score over 30 bombardment points, only IJN ships actually sunk are considered sunk. Scenario 6 - Tassalaronga 1. The IJN Player may score the special rule points only once for each (s) DD unit. 2. DD units marked with an (S) have no torpedo reloads. Scenario 7 - Kolombangara (corrections only) 1. The IJN ships are moving at speed 5. 2. The USN ships are moving at speed 6. 3. There are only 2 Craven DD's in this scenario. Scenario 8 - Empress Augusta Bay 1. Movement visibility is 10 hexes this scenario only. 2. USN ships are moving at speed 4, IJN at speed 5. NEW SCENARIOS Below are two new scenarios; one an inconclusive DD action, and the other a "Tokyo express" situation. Scenario 11, Kula Gulf, 7/6/43 LAND - Configuration "C" (Guadalcanal portion only) IJN Player Hex Ship Speed/Course 2826 2 Kagero DD-4 5/n 2827 2828 2 Shigura DD-3 5/n 2829 2 Fubuki DD-2 5/n 2830 (t) 2831 2 Mutsuki DD-1 5/n 2832 (t) USN Player Hex Ship Speed/Course 3718 2 Fletcher DD-6 5/nw 3818 3919 3 Brooklyn CL-3 5/nw 4019 4120 4220 2 Fletcher DD-6 5/nw 4321 Game Length - 20 Game-Turns or optionally 30 Game-Turns with Reinforcement - IJN Player 3 Mutsuki DD-1(s) on south edge within 5 hexes of land, speed 5, course n, enter turn 20. Use Tassafaronga special torpedo rule. Victory Conditions - victory is awarded on a points basis; points are obtained in accordance with the following schedule: CL sunk = 6 pts. DD sunk = 3 pts. CL DIW = 4 pts. DD D1W = 2 pts. CL P hit = 2 pts. DD P hit = 1 pt. Japanese ships DIW at game end are considered sunk. The IJN player begins the game with 6 points, as the supply (s) ships have unloaded. Each (t) DD has 1 point worth of troops on deck; if the DD leaves the map unhit, the IJN player receives this point, if the DD is hit, neither player gets this point; if the DD is sunk, the USN Player receives this extra point. The level of victory is determined by the ratio of victory points, IJN/USN as follows: Level of Victory Ratio IJN/USN IJN Major 5.00 up IJN Minor 3.00-4.99 Draw 1.50-2.99 USN Minor .75-1.49 USN Major .74 or less Scenario 12 - DD Action off Horaniu 8118143 (Vella LaVella) NO LAND IJN Player Hex Ship Speed/Course 4612 2 Kagero DD-4 3n 4514 1 Kagero DD-4 3/ne 4316 1 Fubuki DD-2 3/n 4317 1 Kagero DD-4 3/n USN Player Hex Ship Speed/Course 3726 4 Fletcher DD-6 7/nw 3826 3927 4027 Game Length - 15 Game-Turns. Victory according to point schedule on Scenario 11; point ratios as per table on Scenario 3. UN ships DIW at game end are considered sunk. If either side leaves map before Game-Turn 10, the opposing side wins. Spotting Range is 16 hexes, this scenario only. "CA" IN SIMS Because "CA" already incorporates the two essentials for SMS - 1. Few (generally less than 20) units per player at any one time, and ... 2. the standard coordinate grid, it is comparatively easy to shift "CA" into an SMS format without changing the rules substantionally (For those who are not familiar with the term, SMS is SPI's new Simultaneous Movement System, which uses a pad that is the same for all SMS games). The following are the rule changes necessary to use SMS with "CA". SEQUENCE OF PLAYER (4.0) When using SMS, the sequence of play is changed as follows: the basic change is that there are no longer any Player-Turns; both players perform the same actions at the same time. A. Sight Determination Phase - Players determine which ships, if any, are "spotted" by opposing forces; firing ranges are determined for gunnery and torpedo combat. B. Operation Plot Phase - Both players secretly plot the operations of all of their units in accordance with section (10.0), indicating all movement, gunnery and torpedo attacks. Spotting and firing range is established for any previously unspotted ship that elects to use its Gunnery Attack Strength. C. Board Movement Phase - Both players maneuver their units on the map in accordance with the instructions written on their SMS Plot Charts, Units not visible to the enemy are maneuvered with both the ship counter and the speed/facing marker inverted; the opposing player may not examine these counters. D. Combat Resolution Phase - Both players, in any order, resolve all gunnery and torpedo attacks. All combat is considered to be simultaneous. Result counters are placed, but results do not take effect. E. Combat Results Application Phase - All combat results take effect simultaneously. Ships accumulating three (3) hits of any type(s) are considered sunk, and are removed from play at this point. F. Game-Turn Indication Phase - Players indicate the passage of one Game-Turn; availability of reinforcements (if any) is determined; victory point records are adjusted. Play then reverts to Phase A for the next Game-Turn [10.0] OPERATION PLOTTING General Rule. In order to create the lack of intelligence of enemy intentions, players initially plot (write down) their intended movements and attacks in secret from their opponent, who is thus unaware of what is planned until it takes place. Procedure During the Operation Plot Phase, players plot, on the SMS Plot Chart, the movement of all their units, and indicate which units are making gunnery and/or torpedo attacks, and the target of each attack. [10.1] MOVEMENT PLOTTING [10.11] Place each ship's Unit I.D. (composed of the ship type and Class Name codes from the ship counter) in one block in the "UNIT" column of the SMS Plot Chart. The row of numbered blocks following each ship's unit I.D. will be used to plot the movement and combat for that ship that turn. [10.12] In the next block(s), place one attack code (if the ship is to attack in that turn) and indicate the Unit I.D. of the target ship. If a ship is to make both gunnery and torpedo attacks in a given turn, then two attack blocks will be required. [10.13] Following the blocks in which attacks have been recorded (if any) plot the movement of each unit, recording each hex to be entered by the unit in this turn. If the unit will expend movement points turning in a particular hex, place a circled number in the block with the hex number to indicate how many movement points were expended in turning. See (6.0) Movement for details on how to move. [10.14] After all of the movement points of the unit have been expended, in the next block, place the final speed/facing of the unit, i.e., the speed facing after completion of all turning, acceleration, deceleration, etc.; this becomes the initial speed/facing for the next turn. [10.2] ATTACK CODES [10.21] An attack code written in a block with a Unit I.D. commits the given ship to make the indicated type of attack on the indicated target. The attack codes are "G" for gunnery attacks and "T" for torpedo attacks. Attacks are made subject to the limitations of section (7.0). [10.22] Decisions regarding combat are final. No changes in attacking units or target units can be made after the end of the Operation Plot Phase. [10.3] SECRECY AND HONESTY Each player's Simultaneous Movement Plot Chart is to be hidden from the other player until the end of the game. If there is any question about the other player's orders, the Player is advised to write them down and compare them with the SMS Plot Chart at the end of the game. A player who secretly violates the rules to gain an advantage in the game, forfeits that game. [10.4] SIMULTANEITY OF COMBAT [10.41] All combat is considered simultaneous. For this reason Combat Results are not effective until the Combat Results Application Phase. Then they are applied to all units that suffered them. [10.42] A ship that suffers a Combat Result in a given Combat Resolution Phase must engage in combat in that phase if ordered to do so by the SMS Plot Chart without any consideration of the Combat Result. The Combat Result does not affect the ship's combat ability in any way until the Combat Results Application Phase of that turn. [10.5] SIMULTANEITY OF MOVEMENT All movement is also considered simultaneous. Both players execute all plotted movement during the Board Movement Phase. All plotted movement must be executed; ships may never alter their movement in response to enemy actions. [7.6] SMS NIGHT TIME SPOTTING [7.61] Most scenarios in "CA" take place at night. There are special restrictions upon firing at night. Ships may only fire guns or torpedos at target ships that are "spotted." [7.62] Spotting occurs in three manners: (a) Whenever a ship uses its Gunnery Strength in a turn, place a spotted marker on it. Torpedo attacks do not cause spotting. (b) Whenever a ship is within eight (8) hexes of an enemy ship, place a spotted marker on it. (c) Whenever a ship has been the target of a gunnery attack in a turn, and fulfilled the conditions (a) or (b) above, it remains spotted for the following Game-Tum only, if it is again under under gunnery attack, even though it does not fulfill the requirements of (a) or (b). [7.63] Spotting is determined only in the Sight Determination Phase. Ships which fulfill the sighting requirements in that phase, and ships which make gunnery attacks (see 10.31) are spotted for that turn. Because spotting is only determined in the sight determination phase, the initial contact between two ships may be made at less than eight hexes. [7.64] Spotted markers are removed at the end of each Game-Turn. Those are all the rule changes necessary to play "CA" in Simultaneous Movement. For those players willing to put up with some slight additional complexity, the Simultaneous Movement System can be used to add a crucial factor to the game - the simulation of preparedness/alertness, which is crucial in all naval combat, but is particularly important at night. The method for doing this will be discussed in a later article if feedback response warrants it. Shown, is an example of how to fill out the SMS Plot Chart as indicated in the rules.
Indicated is the first turn plot for the Allied Player in Scenario 1A. In this case, the first hex of placement is written down because the two capital ships expend their Movement Points turning in this hex; otherwise this hex would not be written down, as the information is given with the scenario. The two capital ships attack the IJN BC's, though the combat is ineffective because of the range (it is merely included to show the mechanics). No torpedo attacks are made this turn. The Allied Player increases the speed of all his ships, and maneuvers to close the range. NB submitted by John Kula (firstname.lastname@example.org) on behalf of the Strategy Gaming Society (http://www.boardgamegeek.com/~sgs), originally collected by Andrew Webber (email@example.com)