Operation Downfall '06

Operation Downfall Scenario Rules

Sections

Dates and Times
Introduction
The Battle
Rules
- Japanese Objectives
- US Objectives
- Victory Conditions
- US Forces Available
- Japanese Forces Available
- Other Rules
- Settings
Change Log
Credits

Dates and Times

Players should register for the scenario to play in it so that they can get mission orders, although walkons are allowed to show up in the Special Events Arena on game day to see if there are any open positions to fill. Operation Downfall will be a four-frame event (four battles). Takeoff will be at 8 pm US Eastern Daylight Time on July 22, August 5, August 12, and August 19, 2006. Players should show up at least 30 minutes prior to takeoff to get situated and briefed.

Introduction

Three and a half years of desperate, bloody fighting between US and Japanese forces have raged across half of the planet Earth. Invasions at Tulagi, Guadalcanal, Wake Island, Tarawa, Saipan, Guam, Luzon, Iwo Jima, Mindanao, and Okinawa, among others, have brought US forces to the doorstep of the Japanese home islands. The invasions have also made a clear and incontrovertible point: Japanese forces are willing to fight to the very last man.

On May 25th, 1945, US Joint Chiefs of Staff approve the first part of Operation Downfall, the invasion of the Japanese home islands. Japanese military commanders see such an invasion coming and are recalling forces to Japan for the final, decisive battle.

Based on actual casualty rates of invasions to date and based upon estimates of the sizeable might gathered for the defense of Japan, some estimates are that Operation Downfall will result in more than one million US casualties and more than 10 million Japanese casualties.

The US hopes that the Manhattan Project, its secret project to develop atomic weapons, will produce results before Operation Downfall is to go into effect, but it is not to be. The last stage of WWII will be fought conventionally.

On November 1st, 1945 -- X-day -- the Allies launch the largest amphibious invasion in human history. Fourteen divisions -- over 400,000 soldiers and Marines supported by the US 3rd, 5th, and 7th Fleets, the US 5th, 7th, 8th, 13th, and 20th Air Forces, the British Pacific Fleet, the British Tiger Force, and the Australian 1st Tactical Air Force -- board the largest number of landing craft ever assembled and head for the shores of Kyushu. The Japanese 40th, 56th, and 57th Armies, and the Japanese 216th Division -- 600,000 men in total -- are ready to defend.

The first part of Operation Downfall, code named "Operation Olympic," has begun.

The Battle

100 or more players on each side will battle it out for control of Japan, with the largest diversity of aircraft yet in any scenario. US forces from a large number of fleets and some land bases will battle it out against Japanese forces from land bases and some fleets. Nearly the entire US plane set (including all late-war variants, even F4U-4's, F4U-1C's, and P-47N's) and the entire Japanese plane set (including Ki-84-Ia's and N1K2-J's) will be available. In addition to Japanese late-war aircraft, the Japanese will have some Me 163's, Me 262's, and Ar 234's available.

To simulate the massive scale of this operation, the scenario will have unlimited lives for participants.

There will be vehicles available for capture of bases, but participation in vehicles is expected to be very light. There will be LVT's, M-3's, etc., but no Panzers, T-34's, or Tigers. This scenario is meant to focus on air-to-air, air-to-ground, and anti-shipping combat and the use of aircraft to facilitate base capture.

Expect vicious dogfights involving a large variety of aircraft types, including late-war US and Japanese fighters, torpedo and dive-bombing missions against a sea full of fleets, long-range heavy-bomber missions sent to flatten industrial targets, and intercepts involving new secret axis aircraft, which have been the topic of many whispered rumors.

Rules

Japanese Objectives

Stop the US from meeting all of their objectives or recapture any of the bases that the US needs for its objectives.

US Objectives

Objective 1 is (a) to destroy Nagasaki city (near p86) and (b) to capture Nagasaki port by capturing p86. Nagasaki city must be destroyed before p86 is captured as, once p86 is captured, Nagasaki city is owned by (and thus unable to be destroyed by) the capturerer. Nagasaki city is destroyed by destroying either both primary Nagasaki city areas or one primary area and four secondary Nagasaki city areas. A Nagasaki city area is destroyed by destroying all of the city objects in it. This includes the bridges along the red dividing lines, any ships in the harbor, towers, churches, or anything else that does not look substantially like a tree. Nagasaki city areas are shown in the close-up of Nagasaki below.

Objective 2 is (a) to destroy Tokyo city (near p59) and (b) to secure Tokyo by capturing p59 and v123. Tokyo city must be destroyed before capture as, once Tokyo is captured, Tokyo city is owned by (and thus unable to be destroyed by) the capturerer. Tokyo city is destroyed by destroying both primary Tokyo city areas and two secondary Tokyo city areas. A Tokyo city area is destroyed by destroying all of the city objects in it. This includes the bridges along the red dividing lines, any ships in the harbor, towers, churches, or anything else that does not look substantially like a tree. Tokyo city areas are shown in the close-up of Tokyo below. The US may not begin objective 2 until objective 1 is met.

Note that it is vitally important to destroy the cities first, then -- only after all necessary city objects are destroyed -- to do the capture. If the US leaves up even one city object that it needs to destroy for meeting an objective, then captures and owns the city, the US will be unable thereafter to win (unless the Japanese obliges the US by destroying the building or capturing the city so the the US can redestroy and recapture it).

To capture a base, the invader needs (1) to destroy all buildings at the base's town; (2) to destroy all ground guns, if any, within a 1-mile radius of the map room (i.e., acks and shore batteries, although there likely aren't any shore batteries within a mile of a map room); and (3) then to get 10 troops into the map room.

The judgement on whether or not a US objective is met is made at the end of the frame. Thus, if there are bases for the US to capture and bases for the US to destroy to achieve an objective, the bases must be owned by the US at the end of the frame, and the areas to destroy must be all down at the end of the frame. If the US captures all the bases and destroys all the areas, then the Japanese come in before frame end and recapture even one base, the US will not have met the objective. If the US meets all other criteria but leaves even one building up in an area that needs to be destroyed, the US will not have met the objective.

Victory Conditions

If by the end of the last frame the US meets both objectives listed above and holds all of the bases listed for capture, the US wins. If Japan keeps the US from meeting its objectives -- or if at the end of the last frame Japan holds even one of the bases listed for US capture -- Japan wins.

US Forces Available

US NAVY AND MARINE CORPS

ALLIED FLAGSHIP

TF85 - USS ENTERPRISE CV-6 (CUSTOM AIRWING - CO's Discretion as per ROC)

AMPHIB ASSAULT/INVASION DEFENSE

TF77 - USS INDEPENDENCE CVL-22 - Airwing 4 - Fighting 46
TF78 - USS LANGLEY CVL-28 - Airwing 4 - Fighting 23
TF79 - USS SANTEE CVE-29 - Airwing 3 - Marine Air Group 24
TF80 - USS SUWANNEE CVE-27 - Airwing 3 - Marine Air Group 40
TF81 - NO CV
TF82 - NO CV

TASK FORCES

TF89 - USS WASP CV-18 - Airwing 1 - Fighting 86
TF90 - USS HORNET CV-12 - Airwing 3 - Fighting 17
TF91 - USS INTREPID CV-11 - Airwing 3 - Fighting 10
TF92 - USS BELLEAU WOOD CV-24 - Airwing 4 - Fighting 30
TF93 - USS SAN JACINTO CVL-30 - Airwing 4 - Fighting 45
TF94 - HMS IMPLACABLE - Airwing 3 - Fighting 5
TF95 - USS RANDOLPH CV-15 - Airwing 3 - Fighting 12
TF96 - USS ESSEX CV-9 - Airwing 4 - Fighting 83
TF97 - USS BUNKER HILL CV-17 - Airwing 4 - Fighting 84
TF98 - USS HANCOCK CV-19 - Airwing 4 - Fighting 6
TF99 - USS YORKTOWN CV-10 - Airwing 2 - Fighting 9

USAAF AirField A88-AirSpawn NE to sector 10-4
Also, A2 will have USAAF planes enabled

3rd FS, 3rd FG, 5th AF - P51D Primary
431FS, 475th FG, 5th AF-P38L Primary
34th FS, 413 FG, 5th AF - P47N Secondary
19th BS, 22nd BG, 5 AF - B24J Primary

Air wing Descrip:

Airwing 1:

F4U-4 - Primary
FM2
SBD-5
TBM-3
PT Boat

Airwing 2:

F4U-1C Primary
FM2
SBD-5
TBM-3
PT Boat

Airwing 3:

F4U-1D Primary
FM2
SBD-5
TBM-3
PT Boat

Airwing 4:

F6F-5 Primary
FM2
SBD-5
TBM-3
PT Boat

USAAF Planes Must AirSpawn from A88 North East or take off from A2. This Air Group will be limited to 1 Squadron of P-51, One Squadron of P-38 and One Squadron of B24. Each Pilot who Successfully Lands at A88 (or A2) after their mission may Re Launch from A-88 (or A2) in the same plane type. All those pilots who fail to land successfully MUST re-up in P-47. This includes the Bomber Pilots.

The number of pilots who can be in each unit is as follows, assuming total number of registered players on US side is N. Each airwing can have up to N/7 pilots. 3rd FS, 431st FS, and 19th BS each can have up to N/7 pilots. The 34th FS has no pilots assigned to it initially -- pilots in this group (with P-47N's) are the ones from 3rd FS, 431st FS, and 19th BS who fail to return in their primary rides.

The USAAF Squadron replenishes after each frame, starting back to full strength.

All Pilots stationed on their Carriers May be Transferred at the COs descretion should their home ship be sunk. In the Event that, as an example, both CVs with F4U-Ds are sunk, they will be assigned to the Secondary Rides.

There are No Life Limits or Plane Limits other than what is available on the ships.

PT boats are available at all ports and from all carrier groups with an active carrier. You may not launch PT boats from a carrier group without an active carrier in it (i.e., if the carrier is sunk).

C-47's are enabled at all land bases owned by the US.

Japanese Forces Available

Special High Tech Planes will be available in Limited Use. The Germans, knowing they were failing, supplied the IJN with their small production of experimental jet aircraft to prevent the capture of the technology. The US Knows of the transfer, and is going to be looking for the airfields where these planes are maintained. Should these bases fall, the IJN will lose the availability of these planes.

The Japanese team will be divided up into sentai (squadrons) as follows, where N is the number of pilots registered for Japan:

Kikka sentai has up to 10 pilots
Shusui sentai has up to 10 pilots
Hayate sentai has up to (N-20)/5 pilots
Shiden sentai has up to (N-20)/5 pilots
Zero sentai has up to (N-20)/5 pilots
Hien sentai has up to (N-20)/5 pilots
Hiryu sentai has up to (N-20)/5 pilots

Kikka sentai gets to fly Ki-84's from any field that has Ki-84's enabled. Also Kikka sentai has 10 Me 262's available for the whole scenario -- each of the 10 pilots in the sentai gets one life in an Me 262. Thus, if he takes off, comes back, and gets a "landed successfully" message, he can fly it again. If he gets shot down or fails to land successfully, he can't fly Me 262's anymore. If all fields where Ki-84's are available get destroyed by the US, Kikka sentai will not be able to launch Ki-84's but can fly any of the Secondary Aircraft, defined below, from any remaining airfield. Me 262's are available only from A5 -- if A5 is destroyed, Kikka sentai will not be able to launch Me 262's until A5 is repaired.

Shusui sentai gets to fly N1K2's from any field that has N1K2's enabled. Also Shusui sentai has 10 Me 163's available for the whole scenario -- each of the 10 pilots in the sentai gets one life in an Me 163. Thus, if he takes off, comes back, and gets a "landed successfully" message, he can fly it again. If he gets shot down or fails to land successfully, he can't fly Me 163's anymore. If all fields where N1K2's are available get destroyed by the US, Shusui sentai will not be able to launch N1K2's but can fly any of the Secondary Aircraft, defined below, from any remaining airfield. Me 163's are available only from A8 -- if A8 is destroyed, Shusui sentai will not be able to launch Me 163's until A8 is repaired.

Hayate sentai gets to fly Ki-84's from any field that has Ki-84's enabled. If all fields where Ki-84's are available get destroyed by the US, Kikka sentai will not be able to launch Ki-84's but can fly any of the Secondary Aircraft, defined below, from any remaining airfield.

Shiden sentai gets to fly N1K2's from any field that has N1K2's enabled. If all fields where N1K2's are available get destroyed by the US, Shusui sentai will not be able to launch any N1K2's but can fly any of the Secondary Aircraft, defined below, from any remaining airfield.

Zero sentai gets to fly A6M5's, which are enabled at all Japanese airfields.

Hien sentai gets to fly Ki-61's, which are enabled at all Japanese airfields.

Hiryu sentai gets to fly Ki-67's, which are enabled at all Japanese airfields. Also Hiryu sentai has 10 Ar 234's available for the whole scenario-- each of the 10 pilots in the sentai gets one life in an Ar 234 (single or formation, at his choice). Thus, if he takes off, comes back, and gets a "landed successfully" message, he can fly it again. If he gets shot down or fails to land successfully, he can't fly Ar 234's anymore. Ar 234's are available only from A12 -- if A12 is destroyed, Hiryu sentai will not be able to launch Ar 234's until A12 is repaired.

Secondary Aircraft are A6M2's, D3A's, B5N's, and C-47's. These are enabled at all fields and may be flown by any sentai at any time.

All ports and vehicle bases will have Jeeps, M3's, and M16's, which also may be driven by any sentai at any time.

Ki-84's and N1K2's will each be available from some number of the IJN bases, not at all IJN bases. The bases that have Ki-84's and those that have N1K2's will be known by the US prior to frame 1. If the US knocks out the fighter hangars at all the Ki-84 bases, the IJN will not have Ki-84's available anymore for that frame, and squadrons (sentai) that have the Ki-84 will need to use the Secondary Aircraft. Likewise for the N1K2 bases.

The IJN CO will have the Unique Opportunity to Recruit and Form His Squadrons to take advantage of the planes and airfields. He will be charged with the daunting task of locating and destroying the invading fleet located somewhere out in the Pacific. The CMs wish to allow as much opportunity as possible to apply his or her own strategy to the situation, and use his players as they are needed.

Other Rules

Although there are unlimited lives, there is a penalty to not landing successfully, so that living matters. The ability to launch in an aircraft, vehicle, or gun is enabled only every 30 minutes for a short time (several minutes). Thus, if you land successfully, you can re-arm and re-fuel and take off again (although bombers will lose their drones when you rearm). If you die, crash, or exit your plane, you won't be able to launch in anything (even a gun) until the next flight window comes up.

Note that, even when flight is disabled, you can join a bomber pilot as a gunner on his bomber. Thus, if you are stuck otherwise sitting around for a while, you can instead join as a gunner if there are bombers up that want you as a gunner.

A88 may not be attacked. The IJN may pursue US aircraft there and attack them over the field, but the IJN may not destroy any buildings, acks, or objects at A88.

1 Sector Movement between frames will be allowed for the Fleets. In any direction. A Total of 1 Sector, so a 10, 10, 5 Position could move to 11, 10 5, or less.

Carriers near land bases may transfer squadrons to the land base. The carrier must be within 3 sectors of the land base. The transfer occurs at the end of the frame with planes available at the land base at the start of the next frame. Once the squadrons are transferred, that carrier no longer can launch primary aircraft unless the squadrons are transferred back to the carrier. The squadrons may be transferred back to a carrier under the same conditions as transfer to the base (just done in reverse).

No Air Spawns are to be used except for A88 out to 10-4 sector.

Settings

Wind. From ground up to 26,000 ft, wind will be set at 5 mph from W to E (or some variation, such as SW to NE). At 26,000 ft and above, there will be a downdraft and strong W-to-E wind, which will limit altitudes and represent the difficulty of the jet stream.

Hangar hardness. 1500 lbs of bomb damage to destroy a hangar.

Hard gun battery. 4000 lbs.

Ammo, fuel, and barracks hardness. Ammo and fuel bunkers and barracks will be nearly indestructible (18,000 lbs). To deny the enemy full use of a base, destroy the fighter hangars, bomber hangars, and vehicle hangars at the base.

Ship hardness. Main arena standard. (There is a bug in the system such that ship hardness, regardless of what the setting is, effectively stays at whatever it is in the main arena.)

Hardness of town buildings and city objects. 350 lbs.

Clouds. None.

Fuel multiplier. 1.0.

Visibility. Visibility 11 Miles. Short icon range.

Radar. Bases flash when enemy aircraft or vehicles are within 32000 ft. Sector counters are off. Friendly and enemy dots when within 25 miles of a friendly radar tower.

Ack lethality. 1.0

Object down time.

Destroyed base buildings (such as hangars) stay down the entire frame. Between frames, 50% of damaged bases are fully repaired (i.e., all objects at the base are fully repaired). Between frames, all captured bases will be fully repaired.
Town buildings rebuild after 40 minutes.
City objects stay down the entire frame. City objects in city areas that were 100% destroyed stay down between frames. Between frames, 50% of city objects in city areas that were not 100% destroyed are repaired.
Ack rebuilds after 40 minutes.
All sunk ships remain sunk for the duration of the scenario. Damaged but floating ships are fully repaired between frames.

Change Log

This section mentions the changes in each version, so that when changes are made to this document, people don't need to read the whole document to find out where the changes are.

v1.0
-- This is the first version released as final candidate.

v1.1
-- Added this "Change Log" section.
-- Added clairity on meeting objectives. The new information was added as the last two paragraphs in the "US Objectives" section.

v1.2
-- Added the strategic map of Japan, showing where US can spawn fleets.
-- Radar changed. See "Settings" section.