Japan '45 Historical Plan/Placement Olympic

[ComradeP]

Operation Downfall, the planned invasion of the Japanese home islands consisted of two stages.

Stage 1: Olympic (invasion of southern Kyushu).
Stage 2: Coronet (invasion of central Honshu).

The Operation Olympic as seen in the game is similar to the original plan, but with different landing locations and 4th Marine Division being swapped with the 2nd Marine Division.



May 1945 Olympic Plan pdf download: http://cgsc.cdmhost.com/utils/getdownloa...singleitem

The original plan envisioned landings in Kagoshima Bay and Ariake Bay, but somewhere along the line the plan was changed to the plan as seen in the game.

The short-term follow-up divisions and AFPAC reserve divisions are not in the OOB, though the 77th arrives a bit earlier than on the employment plan above. The 40th Infantry Division is off-map securing various smaller islands.

There's a "Take Kyushu" campaign scenario, but there might've been some version mix-up between designer and the person compiling the release files as that scenario still only includes the standard US OOB without follow-up units (the US OOB is identical to the one in this campaign scenario).

US military and civilian leaders were very worried about the Japanese build-up in Kyushu. The original plan was made on the assumption that there would be 3 division in southern Kyushu on X-day and that those would be reinforced by about 7 more within a short amount of time. In reality, that number was already reached by late July/early August.

https://www.cia.gov/library/center-for-t...-decision/

From the publication linked to above:

Allied planners feared a 1:1 manpower ratio fight. In the game, it's closer to 1:1.5 or 1:2 in Japan's favour.

What makes the game difficult for the Allied player is that the Allied OOB contains the divisions that were originally scheduled for the landing, whilst the Japanese OOB consists of the August OOB with units that were on the island or redeploying to Kyushu when Japan surrendered.