SGS Rules

Operation Hawaii campaign


SGS Operation Hawaii

Everyone knows the story of the Japanese surprise attack on the US naval, land and air bases at Pearl Harbor and nearby on the morning of December 7th, 1941. The date marks the entrance of the United States in the Second World War. In the hours that followed the initial attack, there were fears and speculation that it would be followed by an enemy amphibious landing and invasion of Oahu. The eventuality of such an assault had indeed been studied by the Imperial Japanese Navy and rejected as logistically unfeasible. But what-if the case has been different?

This game studies a possible land invasion of Oahu, by a small but well-trained force of Japanese Marines and Army troops, specially trained for the operation and secretly carried to destination in the attack force. Key decisions as to what the goal of the operation was, where the troops would land, and how long it would last were taken in an ambitious plan.

The attack force could not supply or sustain the effort too long, a maximum of 3 or 4 days, so the objective was to wreck as much damage and destruction to the military installations, so that the effects of the air strike would be comforted by the devastation laid on the US ground structures.

Can you, as the commander of the Japanese land force, choose the right place to invade, and then conquer and destroy as much as you can in the allotted time? And, as the surprised American commander of Oahu’s defense, can you block the invader, save the base and possibility turn a disaster into a victory?

The game offers to both side an array of different starting options, each at a cost in victory points. The other side will not be aware of your choice, thereby creating new situations at each start of the game.

  • As the Japanese, the crucial choice is that of the landing site. Close to Pearl Harbor, but under coastal batteries fire. Or north of the island, safe from damage and defense but far away. Or on the eastern shore, a possible good compromise between distance and difficulty. Will you send some surprise group to assault a fort? Or carry with you some artillery? Or let the fleet close in to get some extra gunfire support from the battleships?
  • As the American, can you just stay put, as historically and see what unfolds? Or will you invest in stronger defenses and minefields, or create some quick reaction battlegroups to repel the invaders? Or obtain from the War Department more material, and in particular a better air force component? Will all these be enough?

All those options and gambles are yours to discover. The game’s event and cards allow full replay ability thanks to the numerous various situations that they create.


Duration: 4h+
Favored Side: none
Most Difficult Side to Play: Americans

The Operation Hawaii scenario lasts 16 turns, four days between December 7th and December 10th, 1941, each TURN representing usually 6 hours of the day.

Japan plays first, followed by the USA. On TURN 0 (Option Turn), both sides can only play cards, nothing else.

The US forces include United States Army, US Army Air force, US Marines Corps and United States Navy units.

The Japanese forces include Japanese Army and Japanese Navy land and air units.


SGS Operation Hawaii

The map represents the island of Oahu.

The landing beaches (circles off the coast, in the east, south and north) represent the location where the Japanese attackers can be setup (via the options chosen at start).

Roads: movement within friendly regions connected by road is lower by 1 MP compared to regions of similar terrains without roads.

The 3 offmap box representing the location of the respective fleets, when they are present. They can only be entered by air units.

AIR STACKING: in this scenario it is limited to 6 points of stacking in all regions except off-map boxes, where it is unlimited. Most air units have a 1 point stacking value.



The US player wins immedietaly IF he destroyes all Japanese land units.

The Japanese player wins immediately IF he captures all structures on the map or eliminates all enemy land units in play.

Otherwise, the player who has 50+ VP wins instantly. If not, the side with the most Victory Points at the end of the scenario wins the game.


Both sides start the game with 20 VP. Then they have to select a setup option (between 0 and -10 VP cost) and they can (but are not forced to) select between 1 and 3 options, which all cost a variable loss of VPs from the starting total.
One option, which is equivalent to selecting none of the 3 above, brings instead a bonus of + 3VP.


The Japanese player receives VPs during the game via the play of cards which can be activated if the structure indicated on it (fort, airfield, specific building) is currently in the player’s hands.

The US player earns 3 VP at the end of each day (every 4 turns in game turns).
He also gains 1 VP for every military site (airfield, batteries, forts) that he still controls at the end of the game. Each eliminated Japanese land or air unit also brings 1 extra VP.

Last, but not least, each eliminated aircraft carrier (CV ship) or battleship (BB ship) from both sides brings 5 VP to the other side, while cost 5 VP to the owner (so basically 10 points of difference!).



No reinforcements in this scenario, but some cards, linked to initial options or coming (rarely) by draw, will allow for a stronger defense in the begining, at the cost of Victory Points. Namely:

– Tanks (-3 VP): the card adds 2 M3 Stuart light tanks to the US setup .
– Minefields (-5 VP): the card adds one minefield in each of the beaches facing potential landing sites.
– Extensive Air Defense (-8 VP): the card adds 2 squadrons of P40 fighters to the US defense.
– Trucks (-3 VP) : this card grants an extra Truck unit which acts as a morale and combat booster (+1 each) to units the Truck is stacked with.


No reinforcements in this scenario, but 3 cards, linked to initial options, will allow for the following:

– Surprise Fort Assault (-4 VP): Fort Ruger is captured by a surprise assault of an elite SNLF combat group.
– More Battleships (-8 VP): this option grants 2 more battleships (Haruna and Kongo) to the Japanese fleet, and allows the draw of more gunfire support cards (see Special rules)
– Artillery (-6 VP): the card adds 2 artillery batteries to the original Japanese attack force.



In this version of the game, Supply is not activated for either side.SGS Modern Supply source

This is due to the length of the game (4 days, troops would have enough supply to last this much in the field)

NB : the supply markers on the map are just there for cosmetic reasons (and a possible future variant).


In this game, only the Japanese SNLF Marines and US Tanks may breakthrough , and only into 1 region.


On Turn 0, both sides need to chose 1 setup / landing option, and may choose between 1 and 3 other options.

All those options have a cost in VP, which is deducted from the starting total of 20.

Both sides must first select a landing site or initial setup option (between 0 and -10 VP cost).
Each is exclusive of the other, once one is selected, the other two are removed.

Then they can (but are not forced to) select between 1 and 3 extra options giving a certain advantage, or an option that gives nothing but VPs and cancels all the previous 3 options. All of the options which give an extra benefit have a varied cost (between -4 and -12 VP).

In all case you cannot spend more than the 20 VP you started with, some some multiple choices won’t work together if their sum exceeds the limit.

Once options have been selected, all unused card are removed and the game can start.


As most of his aircrafts are involved in the initial strike at the airfields and ships, the Japanese player can’t move any air units on Turn 1 (busy raiding). Similarly, due to initial surprise, US surviving aircrafts don’t fly on turn 1


The weather is generally clear, but bad weather cards may appear, with the effect of usually reducing units movement rates, or even, in some serious cases, preventing air units from flying.


USA receives 1 replacement on the first night (turns 3), 2 on the second (turn 7) and 3 on the third (turn 11), plus a few other via cards.

Japan receives 1 replacement every night turn (turns 3, 7 & 11), one each night for air units only (service) and a few other via some rare cards play (e.g. Rest or Stragglers cards).


There are four (4) cards drawn each turn in this game (from turn 1 onwards), the Japanese player may keep up to 10 of them in hands, while the USA player is limited to 7.


During deep night turns (turns 3-4, 7-8 & 10-11), US units suffer a -1 or -2 movement and -1 combat penalty.

Japan naval air units must return to their own carriers where they will be locked for 1 turn (no night flights).


There are no possible naval battles in this scenario, as both sides naval units are supposed to be far away enough from the island so that a close surface battle is possible (or because US surface ships in Pearl Harbor are too damaged / surprise / unready to go for a fight).

However, naval air attacks are allowed. If a side discovers (done by cards or via events) the enemy fleet, it can send its naval air units to attack it. The rewards (and the cost too) can be great.


There are cards on both sides that provide naval gunfire support (from battleships or coastal batteries).

In game terms, the play of those cards allows the recipient to place a naval support unit in a allowed region (usually coastline or around Pearl Harbor).

Those untis will strike during the artillery phase of a battle with great firepower and only a limited number of time, then will disappear. They will come back into play if their corresponding card is drawn again (representing the limited amount of explosive shells available). So use them wisely.


The regions where the terrain is Jungle and Mountains cannot be entered by US motorized units (tanks, trucks, artillery) unless there is a road there, even if the said units have enough movement points.


The USA player is under full fog of war, i.e. the player cannot see what an enemy stack contains (only an emblem is displayed on those) until they enter in battle with those. On the opposite, the Japanese player cannot see an enemy stack content but he can see the picture of one of the units in the stack displayed on top of that same stack (limited information). Cards will allow examination of enemy stack content.



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