Adding new real units to the Empire of the Sun 2nd Edition

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Empire of the Sun is a grand strategy game: The Historical Imperial Japanese Navy fleet carriers, light carriers, escort carriers, battleships and cruisers behind the counters


I really like the mechanics and the design of the Empire of the Sun (GMT) boardgame. I usually like grand strategy games that have some operational component too. It is hard to mix strategical and operational/tactical concepts in a single game. The strategy games tend to be coarse-grained approximations to the reality. Granularity is reflected on the composition of the units for each counter; basically how many planes, vessels, infantry are represented by a single counter. Empire of the Sun is a strategy game. If you really want to play operational game for the pacific war, then Pacific War (Victory Games), by the same designer Mark Herman, can be an option too. The combats in the Empire of the Sun are very abstracted and because of the time length of each turn (4 months in real time), a single engagement is the convolution of many combats occurred during this period of time. If we want more detail we can therefore play the Pacific War (VG). However, the problem is that playing a full campaign in the Pacific War (VG), or War in the Pacific: Admiral Edition in which each turn represents one day in real time is not feasible for many people due to time constraints. Many of us can only enjoy this hobby during holidays or weekends because of busy working schedule. Therefore, Empire of the Sun provides an ideal solution for playing the entire campaign of the Pacific War with a high degree of realism but still keeping the time involved in a reasonable scale. Anyway, we can always play single scenarios for the Pacific War game or why not to combine Pacific War scenarios with some battles in Empire of the Sun. This is something I’m actively researching and exploring. Players could choose which battle is played in high degree of resolution and which not, but playing in solitaire mode would help to decide this :)

But, once the above general comments have been presented, I would like to discuss about the composition of units of the Imperial Japanese Navy in the game of Empire of the Sun (GMT) 2nd edition. I think some weeks ago, I started some posts with this topic but it was not completed. Since now I bought and received the Empire of the Sun 2nd edition, it is a good moment to continue with this project.

Fleet Carriers, Light Carriers and Escort Carriers


Let’s start with aircraft carriers. The Imperial Japanese Navy commissioned 11 fleet carriers, 9 light carriers, and 10 escort carriers.

CV Akagi, CV Soryu, CV Shokaku, CV Junyo, CV Taiho, CVL Zuiho, CVL Ryujo, CVE Kaiyo, CVL Amagi counters are provided. Hereafter, in parenthesis I denote the commissioned year of each vessel and displacement in tonnes.

First, the fleet carriers divisions are three.

The first carrier division was composed of:

CV Akagi (1927, 36,500) and CV Kaga (1928, 38,200) supported by the 7th Destroyer (DD) Division.

The second carrier division was composed of:

CV Soryu (1937, 16,200) and CV Hiryu (1939, 16,200) supported by the 23rd DD.

The fifth carrier division was composed of

CV Shokaku (1941, 25,675) and CV Zuikaku (1941, 25,675) supported by 32nd DD.

The fourth carrier division (or light carrier division):

CVL Ryujo (1931, 8,000) and CVE Kasuga Maru (Taiyō) (1941, 17,830) supported by 3rd Destroyer Division: Shiokaze, Hokaze.

Note on CVE Taiyou: She was one of four ocean liners converted to escort carriers by the Imperial Japanese Navy (IJN) during World War II. She was the lead ship of her Taiyou-class of three carriers. She was initially used to transport aircraft to distant air bases, and for training pilots to land on conventional aircraft carriers. The ship was later used to escort convoys of merchant ships until she was sunk by an American submarine in 1944.

The third carrier divison (or light carrier divison):

CVL Zuiho (1940, 11,443) and CVL Shoho (1939, 11,443) supported by 22nd DD.

These units composed the carrier fleet of the Imperial Japanese Navy by December 1941.

After that new units were built and commissioned by the Navy:

CV Junyo (1942, 24,150) and CV Hiyo (1942, 24,150) (Hiyo-class)

CV Taiho (1944, 30,250) and CV Shinano (1944, 65,800). The Shinano was a modified Yamato-class ship to become carrier.

*CVL Amagi (1944, 17,480) and CVL Unryu (1944, 17,480). Note that CVL Amagi, Unryu and Katsuragi belong to the Unryo-class.

Note: The Unryu-class was designed based on the aircraft carrier Hiryu. Therefore, they may be better referred as fleet carrier. However, their participation in the was very limited.

Note on CVL Amagi: She was commissioned in August 1944 but never embarked her complement of aircraft and spent the war in Japanese waters. The ship capsized in July 1945 after being hit multiple times during airstrikes by American carrier aircraft at Kure Naval Base. Amagi was refloated in 1946 and scrapped later that year.

CVE Kaiyo (1943, 13,600) and CVL  Katsuragi (1944). Here I have qnother two options. (1) The CVE Kaiyo starts reduced from the beginning so it may indicate that should be considered as a single capital single unit with the corresponding support and protection shield of DDs. In such a case I may suggest to consider the CVL Amagi unit composed of the three CVL of the same Unryu-class. (2) Consider CVE Kaiyo together the remaining two vessels from CVE Taiyou-class (CVE Chuyou, CVE Unyou). In such a case, the reduced factor may indicate weak aircraft capability.

Note on CVE Kaiyo: The ship was originally built as the ocean liner Argentina Maru, purchased by the IJN on 9 December 1942, and converted into an escort carrier, and renamed Kaiyō. The ship was primarily used as an aircraft transport, escort carrier and training ship during the war. She was badly damaged by repeated air attacks in July 1945 and was scrapped in 1946–48.

CVL Amagi (1944, 17480), CVL Unryu (1944, 17,480) and CVL  Katsuragi (1944, 17,480).

Note on CVL Unryu: She was the led of its class and commissioned in mid-1944, but fuel and aircrew shortages limited her use to Japanese waters. The  American invasion of Luzon caused the IJN to order her to transport aircraft and supplies to the Philippines in December. The ship was torpedoed and sunk by an American submarine in the East China Sea and never arrived destination.

Note on CVL Katsuragi. She was the third and final Unryū-class aircraft carrier of the Imperial Japanese Navy built during World War II. She was completed in October 1944 and never embarked her complement of aircraft and spent the war in Japanese waters. The ship was badly damaged in a July 1945 airstrike by American carrier aircraft on Kure Naval Base. After war and repairs, CV Katsuragi was then used as a repatriation transport for a number of months, bringing Japanese soldiers and civilians back to Japan from overseas locations. She was scrapped in Japan beginning in late 1946.

AV Chitose (1938/1943, 11,200) and AV Chiyoda(1938/1943, 11,200). In addition, we can consider the Chitose and Chiyoda. They were designed and constructed as seaplane tender in 1934 and operated Kawanishi E7K Type 94 “Alf” and Nakajima E8N Type 95 “Dave” floatplanes. However they were converted to light carriers by the end 1943 /early 1944. Some expansions have been announced that involved a new Chitose unit, which represents AV Chiyoda and AV Chitose. I think the expansion focus on the searching capability of the unit. As i will show later, I also adapted the unit to the 2nd edition of the Empire of the Sun.

This completes all the existing CV, CVL and CVE that were participating to some extent in the pacific war. There were some units that were projected or constructed by never saw combat or did not have planes to use in combat. These units that are not explicitly mentioned above but that could be abstracted in the above units too are part of particular operations are as follows:

CVL Ryūhō (1934/1942, 16,700)  She was a light aircraft carrier of the Imperial Japanese Navy converted (1941-1942) from the submarine tender Taigei “Great Whale”, which had been used in the Second Sino-Japanese War .  It is considered as the least successful of the light aircraft carrier conversions due to its small size, slow speed and weak construction, during World War II, Ryūhō was used primarily as an aircraft transport and for training purposes. However, she also participated in a number of combat missions, including the First Battle of the Philippine Sea. See the below book for references.


CVL Hosho (1922, 7,470) First commissioned ship that was designed and built as an aircraft carrier and the first aircraft carrier of the Imperial Japanese Navy (IJN). She only participated in the Battle of Midway in June 1942 in a secondary role. After the battle, the carrier resumed her training role in Japanese home waters. She survived the war with only minor damage from air attacks. She was used as a repatriation transport after the war, making nine trips to bring some 40,000 Japanese soldiers and civilians to Japan from overseas locations. Hōshō was scrapped in Japan beginning in 1946.

CVE Taiyou-class: CVEs Taiyou, Chuyou, Unyou.

CVE Taiyou is included above in the fourth carrier division with the CVL Ryujou.

CVE Chuyo (1942/43 was a Taiyō-class escort carrier originally built as Nitta Maru first of her class of three passenger-cargo liners built in Japan during the late 1930s. She was transferred to the Imperial Japanese Navy (IJN) during the Pacific War and was converted into an escort carrier in 1942. She spent most of her service ferrying aircraft, cargo and passengers to Truk until she was torpedoed and sunk by an American submarine in late 1943 with heavy loss of life.

CVE Unyo was originally built as Yawata Maru, one of three Nitta Maru-class cargo liners built in Japan during the late 1930s. She was transferred to the Imperial Japanese Navy (IJN) during the Pacific War and was converted into an escort carrier in 1942. She spent most of her service ferrying aircraft, cargo and passengers to various bases in the Pacific until she was sunk by an American submarine in 1944.

CVE Shinyo (1943, 17,500) . The translation of her name is “Divine Hawk”). She became an escort carrier after being converted from the German ocean liner Scharnhorst.  After the IJN  purchased the ship, which has been trapped in Kure when war started, and also due to the severe disaster in the Battle of Midway (1942) in which four fleet carriers were sunk, the IJN decided to convert her into an aircraft carrier and finishing it by December 1943. The Shinyō only participated in convoy escort operations in the western Pacific until November 1944 when the US submarine Spadefish sunk the Shinyo with four torpedoes when she tried to deliver new aircraft to Singapore.

CVE Akitsu Maru-class: Akitsu Maru (1942, 11,800), Nigitsu Maru (1942, 11,800)

The Akitsu Maru was initially a passenger liner but after acquired by the IJN was fitted with a flight deck above the hull. However, she had no hangar so the aircraft were stored below the flight deck on the original main deck. Conventional aircraft were able to fly off from her deck but could not land aboard due to the short deck length and lack of landing mechanisms.  She could also carry 27 Daihatsu class landing craft. Akitsu Maru’s planned role was to provide aircover during amphibious and landing operations (as an IJA Landing Craft Deport Ship  (Testusei dai hatsudotei) in practice the ship and her sister ship the Nigitsu Maru were essentially aircraft ferries.

CVE Shimame Maru-class: Shiname Maru (1945, 11,989). The class consisted of two oil tankers of 10,002 gross register tons (GRT) that were modified by the Navy to provide minimal anti-submarine air cover for convoys going from Southeast Asia to the Japanese homeland. The conversion consisted of fitting a full-length flight deck, a small hangar, and a single elevator. An island and catapults were not installed. She had capacity for twelve planes. Ōtakisan Maru was laid down in September 1944 and launched in February 1945. However it was never commissioned.

CVE Yamashio Maru-class: Yamashio Maru (1945, 16,119).

In 1944, the Japanese Army decided to acquire its own escort carriers to provide aerial anti-submarine cover for troop convoys. It therefore chartered two partly built Type 2TL Tankers, Yamashio Maru and Chigusa Maru, for conversion to auxiliary escort carriers. The conversion was extremely simple, with a 107-metre (351 ft 1 in)-long flush flight deck added. There was no hangar, the ship’s eight Ki-76s being stored on deck. Her sister ships, Chigusa Maru and Zuiun Maru, were incomplete when Japan surrendered and served after the war as tankers: Chigusa Maru was sunk in 1945. The ship was repaired as tanker in 1945 and scrapped in Sasebo in June 1963. Zuiun Maru was scrapped in Oskata on 15 June 1964.

CVE Kumano Maru-class: Kumanu Maru (1945, 8,258). She was comissioned in MArch 1945 and did not see War action due to fuel shortage. After war she was a repatriation ship. The CVE Tokitsu Maru was still under construction when the war ended. She was launched in 1947 as merchant service ship.

By observing these data of the abstracted units, I think the above discussed list is appropriate for the game. It is a strategy game so the counter is not only the capital ships they represent. They may include the protection small units like DD. I think it is good to try to keep the number of capital ships represented by each counter as two as maximum. Then, it is easy to know that one ship was lost when the counter is reduced. This may not be possible in lower rank units such as heavy cruisers and light cruisers. And I dont know the case of US Navy because they really have many CV and CVL Task Forces. but this time i only focus on the IJN.


new counters empire of the sun game

Some new counters such as BB Fuso, CA Tone and BB Ise. The CVBB Ise is re-done to adapt new white color of IJN. Reduced counters are also re-done.


Now I describe the battleships. The counters are BB Hiei 17-14, BB Kongo 13-14, BB Nagato 20-14, BB Yamato 18-18. Here we have some complicated decisions and assumptions to be made.

Basically, Kongo-class was composed of BB Hiei, Kongo, Kirishima and Haruna. All four have similar capabilities so I do not know why the designer gave 17 points of strength to Hiei and only 13 to Kongo counter. It may be possible that the designer included BB Fuso and BB Yamashiro in the BB Hiei counter.

In any case, I thought I could manually create a new counter to address this issue and be able to enjoy all the historical units in the game which adds more flavor to me. Of course, I’m not game designer so it may alter the outcome of the games to some extend but since I plan to mainly enjoy the game in solitaire mode there is not problem for this private setting.

Similar problem happens with the BB Ise and Hyuga. They are not represented as counter but as similar case as BB Fuso and BB Yamashiro, they might have been diluted in BB Nagato (which has 20 streght points) and BB Kongo with 17 points. Basically, I would like to have the BB Ise counter and BB Fuso as independent counters so each counter represent two battleships.

So, my new setting for Japanese Battleship would be:

BB Nagato and Mutsu 20-14

BB Yamato and Musashi 18-18

BB Kongo and Kirishima 17-14

BB Hiei and Haruna   13-14

BB Fuso and Yamashiro 12-14

BB Ise and Hyuga 12-14. Some other people have provided an extension for the CVBB Ise and a new counter too. So I think it is activated  in 1943 from BB Kongo or BB Nagato unit. I prefer to have it as independent unit and in 1943 I can change it to CVBB counter:

CVBB Ise and CVBB Hyuga 7-14-2. So the defense stregth is kept the same but the naval surface combat strength reduced to increase the air combat capability to 2.

Maybe, I’m not sure yet, to compensate the added new strength factors, we can decrease the factors for the BB Nagato and Kongo as follows:

BB Nagato and Mutsu 12-14

BB Yamato and Musashi 18-18

BB Kongo and Kirishima 13-14

BB Hiei and Haruna   13-14

BB Fuso and Yamashiro 12-14

BB Ise and Hyuga 12-14.

CVBB Ise and CVBB Hyuga 7-14-2


I think Fuso and Yamashiro, Nagato and Mutsu were less capable and upgraded than Kongo-class which can explain the difference in the factors. 23 independent factors were added and 11 substracted so we gave the IJN a small advantage of 12 factors.


Heavy Cruisers


The case of the heavy cruisers is not complicated. The game provides four counters:

CA Aoba, CA Mogami、CA Takao and CA Nachi. Basically, the Imperial Japanese Navy had 18 heavy cruisers divided in five main classes (if we consider Aoba and Furutaka class as the same class then only four).

6th Cruiser Dvision 12-10

CA Aoba, CA Kinugasa, CA Furutaka, CA Kako supported by 9th Light Cruiser Division CLD.

The speed of the cruisers are between 36~33 knots and 6 x 200 mm main gun batteries

4th Cruiser Division 12-10

CA Takao, CA Atago, CA Maya and CA Chokai supported by CLD depending on task force composition.

The speed of the cruisers are 35.5 knots and 10 x 200 mm main gun batteries

5th Cruiser Dvision 12-10

CA Nachi, CA Haguro, CA Ashigara, CA Myoko supported by CLD depending on task force composition.

The speed of the cruisers are 36 knots and 10 x 203 mm main gun batteries

7th Cruiser Division 10-10

CA Mogami, Mikuma, Suzuya and Kumano supported by CLD depending on task force composition.

The speed of the cruisers are 37 knots and 10 x 200 mm main gun batteries.

CA Tone and CA Chikuma 8-10-2

The speed of the cruisers are 35 knots and 8 x 200 mm main gun batteries and 6 x air floatplanes

CA Tone and CA Chikuma were designed for long-range searching missions and had a large seaplane capacity. They were employed in the pacific war embedded with an aircraft carrier task force, or as part of a cruiser squadron and always operated together. I think the designer wisely did not include that counter in the game because they are abstracted in the average strength of the carrier counters, in particular, Akagi, Soryu and Shokaku.

But I really like flavor! and I would like to have them as independent counter so I made new one for them. The counter has 8 strength points (less than other CA because only two ships, less batteries and more airplanes) and added 2 for air naval strength. But this strength should be used as searching strength rather than attack strength. I think rules should be discussed further in different post.

Light Cruisers and Destroyers

Then, the CL and DD counter remains but we only have one the CL Tenryu and DD kamikaze. I think we do not need to add new ones for theses classes. They are distributed in all the higher rank classes in escorting missions. These two represent high density of such ships for specific large naval operations so it is fairly represented as it is.

Last but not least, if you have any question or comment on how to improve the game mechanics adding new counters or granularity (adding air squadrons to the carriers for example) let me know or post something.

Have a great game with EoTS!




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  1. The reason Kongo is a 17-14 and Hiei a 13-14 is because Mark added more cruisers to the Kongo group. Your missing cruisers are there. The Nagato counter actually represents the entire battle line: BB Nagato, Mutsu, Ise, Hyuga, Fuso, Yamashiro. All of these ships are WWI vintage and not modernized, number of guns and caliber aren’t the only factors to determine how strong a counter should be, but speed, doctrine and operation also count.

    In short there are a lot of “soft” factors baked into counters and you won’t necessarily find a hard and fast formula (balance is also key).

  2. Thanks for the comments! It’s good to confirm that the CA Chikuma/Tone were indeed abstracted in BB Kongo counter.

    The BB Nagato (20-14) counter will be decomposed into BB Nagato (12-14), BB Ise (12-14) and BB Fuso (12-14).
    Then the BB Kongo (17-14) counter will be composed into BB Kongo (13-14) and CA Tone (8-10-2).

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