Win in 4:

A Training Exercise in the Empire of the Sun End Game

Editor's Note: The following article came out of an online game between Mark (Allies) and myself that came down to the final roll of the dice. As with most long strategic games, the endgame is not played out as frequenty as the opening salvos, so pay close attention because Mark sheds light on the nuances of Operation Downfall.

One of the most difficult aspects of Allied play in Empire of the Sun is undertaking a successful invasion of Japan. An invasion, and subsequent capture of all hexes on Honshu, is necessary for the Allies to win the game if (i) blockade victory (which requires isolating Japan for 3 turns) is not achieved; and (ii) nuclear victory (which requires reducing Japan to 1 resources, play of both Tojo and Manchuria, and four turns of successful strategic bombing) is not possible.

An invasion of Japan often is typically divided into two distinct phases: First, successfully landing on the Home Islands. Second, successfully clearing Honshu. The first phase often includes, as preliminary steps, eliminating or virtually eliminating the Japanese Air/Naval units in the area, followed by Allied Air/Naval sweeps to reduce number of land steps the Allied invader confronts. Once these prerequisites are achieved, the Allied player -- hopefully having saved operation Olympic/Coronet for the occasion -- invades a Honshu port. The prerequisites are necessary because, to ensure elimination of the 12-12 garrison step, 5 steps of US ground forces are required to ensure that the invasion hex is taken. For on a “2” result, which will occur 30% of the time, the Allies will lose 4 ground steps. Invading Japan is thus bloody business, and requires substantial Allied resources.

This scenario focuses on the second step of the Campaign: How to defeat Japan once the Allied forces are ashore. Given enough time, Japan’s defeat is inevitable. But what makes Empire of the Sun a great game is that the Allies are on the clock. Often, it seems, the invasion of Honshu cannot be conducted successfully until Turns 11 or 12, when time is running out. The end game thus takes on the characteristics of a chess match for both players. The Allied player has to optimize his odds of wining given the limited activations permitted by the cards; the Japanese player seeks to run-out-the-clock, usually with only a few units left on the board.

The following scenario, drawn from an actual game, depicts such a chess match. The situation is Turn 12. The Allies have just unleashed Operations Olympic and Coronet to land in Honshu. The landing was preceded by Air/Naval sweeps that wiped out Japan’s last Air/Naval unit (the Yamato) and eliminated numerous ground steps. In order to win, the Allies need to clear the rest of Honshu with only 4 cards, which include only 2 usable EC Offensive. The challenge is daunting; but by no means impossible.

Starting Force Dispositions

Hex Control

Japan owns all hexes not currently occupied by Allied units depicted above, for purposes of this scenario. Japanese 12-12 intrinsic steps have been eliminated only in the two hexes of Honshu occupied by Allied units, Osaka and Ominato.

Starting positions

Cards

The US has the following Cards left in its hand: (a) #56 Typhoon Task Force; (b) #48: New China Army: Stilwell; (c) #39 Sextant Conference; and (d) #38 Operation Tarzan. Note that (d) cannot be used as an offensive with any HQ other than CBI-stationed SEAC, as Chinese units are still on the map.

Japan has (a) 1 pass; and (b) Operation KE (card #35, which permits strategic ground transport no matter supply/activation situation ignoring Allied AZOIs).

Remaining Cards

Other Information

US Political Will is 3; so the Allies can afford to have U.S. units completely eliminated (although the U.S. has precious few ground units after the losses in Olympic and Coronet).

The U.S. has 5 ASPs remaining for the turn.

All Allied units are in range of CenPac in Oahu, and will be in all locations in Honshu.

The U.S. is up for its next card on Turn 12.

If playing this scenario solitaire as the U.S. player, play Japan as follows: The Allied player should conduct reaction for Japan as if playing the Japanese side. After the first Allied Offensive, the Allied player should decide whether Japan would pass or use Operation KE to bring the Palau-based (9-12) XXXX to a Japanese-controlled Honshu port. If the pass is used, KE will be used after the 2d Allied card. The (9-12) XXXX should be evacuated to Nagoya, Kure or Tokyo, if any are available, with a preference for the first two, because of the rough terrain.

US Offensive #1

Typhoon Task ForceCenPac activates 6 units

The Allied Player has two problems. First, the remaining four cards include only 1 offensive that permits naval units to be activated, and 2 cards that cannot be used as 2 OC offensives. The Allies, in other words, have few activations and battle hexes, and are running out of time. Second, the losses from Operation Coronet and Olympic, although typical, have left the Allies with few full strength units. This is important because, with few activations remaining and a number of Japanese 12-12 intrinsic garrisons to eliminate, full strength units are extremely valuable.

Typhoon TF Offensive vs. remaining Japanese reduced armies ("9-12's")

The Allied plan is thus to minimize the number of times each hex must be attacked to take it. This means clearing out the remaining ground forces, if possible so as to maximize the use of the 2 OC plays to take hexes manned only by 12-12 garrison steps and redeploy full strength units to and within Honshu.

The Allies, accordingly, play Card #56, Typhoon Task Force, as an Event for 6 activations to eliminate the three remaining (9-12) XXXXs in Honshu. These units can be eliminated in Air/Naval combat because the rules specify that the intrinsic 12-12 step is the last step in a hex to be eliminated. Note that the reduced Korean Army cannot be eliminated through Air/Naval combat because it is already the last step in its hex. Note also that all the battles are auto-kills with the +3 modifier for including a U.S. air-capable unit, and the Allies use 30 Air/Naval steps in the hexes adjacent to the Korean Army to ensure that the Japanese player does not want to risk reacting that unit into any of the battles (there is no reason to move the unit as the Japanese player; the Japanese player wants to force the Allies to assault the Korean Army).

Positions at the end of US offensive #1. Note that the empty hexes in Japan are still Japanese controlled and still contain the "intrinsic" one-step 12-12 unit.

Japan Offensive #1

Japan uses its last pass. The Koreans are as well positioned as they can be and Japan prefers to save Operation KE as a nasty surprise for the Allies after the Allies have committed to their next play.

The Korean Army is "safe" from bombardment by the US forces because the last ground step in a hex cannot be eliminated by air/naval attack. The intrinsic ground units (which only exist in Japanese Home Island cities) count as this last step.

US Offensive #2

Sextant ConferenceOC offensive with CenPac for 5 activations.

Kure is taken and the "Big Boys" move to Ominato.

This the pivotal play for the Allied strategy. The Allies take Kure with a 2 OC CenPac Offensive (Sextant Confernece), using 3 activations, while moving 2x22-12s to Ominato for the big push against the Koreans, Tokyo, and Nagoya. The force invading Kure will ultimately take Koyto. The Allies are able to do all this with only 5 activations because they use 2 full strength Marine units and an (11-12) XXX to invade Kure, achieving the 5 steps necessary to take Kure, and since the (9-12) was eliminated, no Air or Naval cover is needed. The intrinsic 12-12 step achieves a 1.5 result, killing the (11-12) XXX that sailed from Ominato to Kure and flipping both 12-12 Marine XXs, which take the hex (auto-kill of 12-12 intrinsic step).

Japan Offensive #3

Operation KEas EC.

Operation KE brings home the reduced 18th Army.

The Allies feel they now have a good chance. Nothing outside Japan is in supply, because the Allies have uncontested Air ZOCs over every Japanese Home Island port. So, the Allies reason, Japan’s last card is irrelevant. Once it is played, whatever it is, the Allies will proceed with their plan to eliminate the Korean Army with a 2 OC and use their last offensive to take their best shot at the 3 remaining cities.

The Japanese Player says: “Not so fast!” Mustering Japan’s last resources, he plays Operation KE to move the stranded (9-12) XXXX in Palau to Nagoya (as far away from the U.S. forces as it can be placed). Operation KE can be played even if the units are not in supply or activation range, and the units may strategically move to any port ignoring Allied air units.

US Offensive #3

Operation TarzanOC offensive with CenPac for 5 activations.

Japanese Kor Army eliminated.

The Allied player is stunned, but he sticks to his plan. All three ground units in Ominato -- the 2x 22-12s and the (11-12) attack the Korean army, supported by 30 air naval factors (a BB and CV). This takes all 5 activations of the Allied Player’s 2 OC play, which is Operation Tarzan (as noted, this Offensive cannot be played as an Event by CenPac because a Chinese unit is on the map in range of SEAC). The Allies send the air/naval support to inhibit reaction by the (9-12) in Nagoya; had it reacted, the Allied Player could have eliminated either Japanese ground unit in Air/Naval Combat.

The Allies do well. Both sides roll a “1” result, and the (9-18) Korean Army is eliminated without inflicting any Allied casualties. The Allies breathe a big sigh of relief. Those full strength 22-12 XXXs are needed for the final assault on Tokyo and Nagoya. The Allies included the (11-12) XXX in the attack in case one of the 22-12s was flipped by a lucky Japanese 1.5 or 2 result; that would enable 2x (11-12) XXXs to attack Nagoya with the last card play, and have some chance of success.

US Offensive #4

New China ArmyEC offensive with CenPac for 6 activations.

The Allies now unleash operation “roll the dice.” Apparently the Allied cause is too busy rebuilding Europe to devote resources to the Pacific; the Allied player’s final offensive is New China Army, an Air/Ground units only Offensive. CenPac has 6 activations to take 3 Japanese cities (Tokyo, Kyoto, Nagoya) garrisoned by 12-12 units and, in the case of Nagoya, an 9-12 that cannot realistically be eliminated through Air/Naval combat.

The Allied operations are as follows:

1. 2x (8-12) Marine XXs from Sasebo and 1x (8-12) Marine XX from Osaka move into Kyoto. These 3 units guarantee elimination of the 12-12 intrinsic step (24 factors; minimum .5 result), and, equally importantly, at least 1 U.S. step is guaranteed to survive. The Allies could take more risk here and use only 2 units, but that it is robbing Peter to take Paul given the limited number of activations: The Allies’ best place to take a risk is Tokyo, where the terrain is clear.
2. One 22-12 XXX and the (11-12) XXX outside Nagoya assault the city. No air or naval cover possible, given lack of activations. The Allies will win this battle if (i) both sides roll a .5 result; or (ii) the Allies roll at least a 1 result and Japan does not roll a 2 result. This is about a 50/50 chance of success.
3. Finally, Tokyo: The last 22-12 assaults Tokyo by itself; with just one more activation, this too could have been an “auto-kill” as at Kyoto. The Allies, however, need to take a significant risk somewhere, and it is here. The Allies need to roll at 1 result and Japan needs not to roll a 2 result. The odds here are about 63% of success.

The Allied player takes a deep breath and rolls the dice.

At Kyoto (as expected) and Nagoya, Nimitz receives good news. Both sides roll .5 results at both locations. Both cities thus fall without any Allied casualties. (At Nagoya, a .5 result kills the (9-12) XXXX; Japan loses the battle because it takes more step losses and the 12-12 is eliminated for inability to retreat).

The game thus depends on the outcome of the Tokyo battle. Here, the dice remain cold. Both sides roll a .5 result. No casualties, but the 22-12 is repulsed!

Japan wins the game by the narrowest of margins, with just the intrinsic garrison in Tokyo holding out.

Final Positions (Tokyo is Japanese controlled)

Final Analysis

Could the Allies have done better? Certainly, some risk could have been taken in invading Kure by using only 4 steps, leaving a full strength 12-12 Marine XX in Ominato and shipping a 22-12 XX into Osaka instead of Ominato. If Kure fell with only 4 steps invading (which it would if Japan does not roll a 2 result, or 70% of the time), this would have enabled the Allies to attack Kyoto with only 2 units (an 22-12 XXX and 8-12 XX) and guarantee an auto-kill, leaving another, critical unit for the assault on Tokyo (likely invading with an ASP), which would have made Tokyo automatic for the Allies. In other words, such a course would have traded a 30% risk of failure at Kure to eliminate the 36% risk of failure at Tokyo on the final card play.

The cold numbers say the Allies should have taken the risk at Kure instead of at Tokyo. A small possible mistake by the Allies, but in the chess game that is the end game, every activation can -- as here -- matter.

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