HOWTOPLAY

==Harris==
by Edward Cree
--How to play--

NOTE: Harris is considerably unfinished; some gameplay mechanics are still not finalised, some game data haven't been written yet, and there are a few balance issues.  At present, the first major unimplemented part is the Invasion preparations in April 1944, so you can play at least that far without experiencing problems.  Be warned, however, that future versions of Harris may not preserve savegame compatibility.

Contents
~~~~~~~~
* Object of the game
* Targets
* Bombers
 - Mods and Marks
 - Wear and Tear
* Sun and Moon
* Weather
* Flak
* Fighters
* Aircrew and Training
* Stations and Squadrons
* Navaids
 - Gee
 - Oboe
 - H₂S
 - G-H
* PFF
* Window
* Filters
* Bombloads
* Budget
* Reference
* Tutorial

Object of the game
~~~~~~~~~~~~~~~~~~
Harris is a rather open-ended game; it is (currently) up to the player to set goals and objectives.  However, loosely stated, the object is to destroy Nazi Germany by air attack.  This is achieved by launching bombing raids against targets from a list (which changes over the course of the war), doing maximum damage to those targets while minimising losses of your precious bombers.  If you fail to do sufficient damage, the Air Ministry will lose confidence in you, while excessive losses will cause the morale of your crews to deteriorate.  If either morale or confidence falls too low, you will be sacked and the game will end [Not yet implemented].  Otherwise, the game ends on VE Day, 8th May 1945 [Not yet implemented].

Targets
~~~~~~~
The targets are divided into several classes, as follows:
* Shipping.  Coastal shipping lanes, fleets, and major canals; attack these to sink enemy ships.
* Minelaying.  The laying of mines in shipping lanes and estuaries, while unspectacular, is a positive contribution to the war effort.
* Airfield, Bridge, or Road.  These tactical targets will usually pop up during land battles (ie. Spring 1940 and 1944-45).
* Specific Industrial targets.  Named factory complexes are the main strategic targets from mid 1940 to early 1942.
* Cities.  From February 1942 onwards, entire cities are the target of most strategic raids.  Destroying them all will cripple Germany's capacity to wage war.
* Leafleting.  Many cities are also, from the beginning of the war, targets for the dropping of propaganda leaflets.
Geographically, the target map can be partitioned somewhat: (See the accompanying map in map/target_map.png)
* France and the Low Countries.  Occasional tactical targets will pop up here.
* Niedersachsen and Schleswig-Holstein.  Many docks, ports and shipyards; also the major industrial cities of Hamburg and Bremen.
* Ruhr Valley.  The heart of Germany's coal-driven heavy industry is here, with such industrial centres as Essen, Cologne and Duisburg.
* Berlin.  The sprawling German capital is a major objective in itself.
* Bavaria and Baden-Württemberg.  Cities like Munich and Nuremberg, deep in southern Germany, are the most distant targets.

Bombers
~~~~~~~
You start with an assortment of light and medium bombers - Blenheims, Whitleys, Hampdens and Wellingtons.  You can direct, in broad terms, the priorities for further production, by means of a control on each bomber type labelled "NONE", "LOW", "MED" and "HIGH".  For every bomber built of a type with LOW priority, 3 will be built on MED and 6 on HIGH.  The total volume produced depends on your Budget, which is an abstraction of the amount of resources the Government is willing to devote to building up the bomber force.  This is increased by successfully attacking, and otherwise gradually diminishes over time.  (See the section "Budget" below for details)
There are also limitations on the maximum production capacity of each bomber type.  This capacity can 'store up' over a few days; its level is shown in the vertical green bar to the right of the priority indicator.  If a bomber purchase is held up by lack of capacity, an orange "P!" will appear to the right of the priority indicator.  Note that this will hold up purchases of ALL types; your budget will be stored up, not spent on other bomber types.  The production capacity for each type increases gradually with each new bomber of that type produced.
As the months and years pass, new types of bomber are developed, and older ones become obsolete and are retired from the front line (and eventually from training units too).  Each type of bomber has its own combination of (among other factors) speed, payload, serviceability, survivability and range.
Because the Government wishes to encourage the development of new aircraft types, for the first four months of any new type's life, you will be forced to buy them at least at LOW priority, though you can set the priority higher than this if you wish.  This will be denoted by a green 'N' to the right of the priority indicator.
Also, when a new type enters service, you will receive a flight of 15 bombers of that type, which are not paid for out of your budget.

Mods and Marks
--------------
Sometimes, a bomber manufacturer will devise an improvement to an aircraft type which is not a big enough change to make it an entirely new type.  These come in two forms: 'mods' (modifications) which are retrospectively applied to all aircraft of the type in service, and 'marks' which apply only to subsequent production.  You will generally receive a message when either happens.
It is thus possible for your forces of a given type to consist of a mix of different marks.  For instance, if you start the game in 1939, your AW Whitleys are a mixture of Mk III, Mk IV and Mk V aircraft.  You can get detailed information about marks in the Intel: Bombers screen; a 'Force breakdown' table will appear to the right of the picture, and a pair of arrow buttons allow you to inspect the stats of older marks.
You can also filter by mark when assigning bombers to a raid; see the section "Filters" below for details.
In the special case of the Handley Page Halifax (Mk I, Mk III), the change between marks is big enough to warrant a new type, so these do not use the game's mark system.
Older marks are often best put to use in training units (see the section "Aircrew and Training" below).

Wear and Tear
-------------
A bomber does not last forever.  Each time it flies an operation, or is used for training, it accumulates 'wear', which slightly reduces its performance.  On reaching 100% wear, it is no longer airworthy and is automatically scrapped.  At an earlier threshold, which defaults to 30% but is configurable per mark, the aircraft will be automatically sent to a Training Unit.

Sun and Moon
~~~~~~~~~~~~
The phase of the moon is shown in the top left of the control center, next to the date.  During the full moon, your bombers will navigate more accurately, but will be at greater risk from flak and fighters, as compared to the new moon.
Sun rise and set times vary with location; when the cursor is hovered over the map, the times for that location are shown.  When the sun is up, its bright light will have a similar but much stronger effect to that of moonlight; it's generally very dangerous to be caught over enemy territory in daylight.  During the summer, the nights are shorter, limiting the distance your raids can safely penetrate.

Weather
~~~~~~~
Cloud cover is shown on the map (if the weather overlay is enabled), and has multiple counteracting effects.  Thick cloud makes it harder for your bombers to navigate and bomb accurately, but also makes it harder for flak and fighters to attack them.  In both cases electronic warfare can somewhat mitigate this — radionavigation and airborne-intercept radar are both unaffected by clouds.  Note that the weather situation continues to develop after a raid is launched — prevailing winds tend to drive weather patterns eastward — so a target that's clear when you're planning your raids could be overcast by the time your bombers get there.
Weather at base is also a constraining factor, particularly early in the war: during the depths of winter, grass airfields can become waterlogged, preventing take-off.  Airfields which are 'clamped' appear in blue on the Stations & Squadrons screen, and bombers based there cannot be assigned to raids.  Paved airfields are much less susceptible to this, but excessively heavy snowfalls can still block their concrete runways on rare occasions.
A red "W!" by the priority selector indicates if any aircraft of a given type are unavailable for this reason.
Don't expect the displayed temperature and pressure values to make meteorological sense — the game's weather model is very much abstracted and simplified, and is more 'plausible fakery' than 'realistic simulation'.

Flak
~~~~
Anti-aircraft defences, or 'Flak' (from the German 'Fliegerabwehrkanone' - anti-aircraft cannon) are one of the threats to your bombers' survival.  Flak takes two forms: flak batteries positioned to cover the approaches to Germany, and defences around the targets themselves.  The strength of a target's flak defences are indicated by the grey bar against the target's name in the target list (the blue bar indicates how damaged the target is, excluding shipping targets).  Flak batteries are marked on the map with purple dots.  A few are a brighter pink colour; this denotes that the flak is controlled by radar, making it much more accurate and deadly.  These radars can also control individual fighter aircraft (in so-called 'Himmelbett' fighting), which will be covered in the next section.  Of course, the Germans aren't so considerate as to tell you where their flak batteries are; you will only know of a given flak site after a bomber has flown near it and lived to tell the tale.
It will usually be impossible for your bombers to avoid all of the flak batteries, as the Germans lay them out in great belts - the Kammhuber Line and the Atlantic Wall - which your bombers must cross to reach Germany.  There are also clusters of flak batteries in major target areas such as the Ruhr Valley.
The more rapidly flak fires, the less accurate it becomes; so losses can be reduced by concentration.  Conversely, if you send aircraft on separate raids all over Germany, each one will get a flak gun all to itself.

Fighters
~~~~~~~~
German fighters are the /other/ threat to your bombers.  The Germans will deploy their fighters in different ways as the war progresses.  Initially, they will simply send fighters to cover any target that's threatened by the approach of your bombers; these fighters will attack visually, so are much more effective in strong moonlight and clear skies.  As the Germans begin to build Würzburg radars alongside their Flak batteries, they will use these radars for 'Himmelbett' ground-controlled interception - each radar station controlling a single patrolling fighter; the remaining fighters will be disposed as before.  Late in 1942 the Germans will deploy 'Liechtenstein' airborne radar into their twin-engined nightfighters (single-engined fighters are too small to carry radar), enabling them to find and attack bombers without individual ground-control.  In 1943 their tactics will change to the 'Tame Boar' system, where a single ground controller will broadcast to all fighters informing them of the progress of the bomber stream and directing them to its general location.

Aircrew and Training
~~~~~~~~~~~~~~~~~~~~
No matter how good your bomber aircraft, they can't fly themselves into battle; each type requires a full complement of aircrew of specified types — varying from the two-man pilot-navigator team of the Mosquito to the seven-man crews of the heavy bombers.  These brave airmen must first be trained in their particular skills, passing through a multiple-stage pipeline which you can control through the "Crews and Training" screen.  The skills they acquire, both in training and subsequently on operational flights, will improve the bomber's effectiveness in appropriate ways; for example, an experienced navigator helps the 'plane to stay on track and find the target, while a skilled gunner is more likely to spot and see off an attacking fighter.
The training pipeline has up to four stages (depending on the date).  Basic Training, the first stage, is abstracted out, and will feed green recruits into the system at a rate depending on how many instructors you have.  (A crewman who has completed his tour of 30 operations will spend six months instructing before returning to the 'front line'.)  The other stages have a 'dwell time', the number of days of active instruction a crewman must receive before completing that stage; a configurable percentage of graduates from each stage will continue on to the next, with the rest going straight to operational units.  As well as instructors, trainee crews also require aircraft, which you provide by assigning bombers to "Training unit" at the end of the target list.  (Unlike real targets, bombers stay assigned to "Training unit" from one day to the next, unless you explicitly remove them.)
Aircraft and instructors are assigned from the rightmost end of the training pipeline first.
Crews at OTU may use any medium bomber (except the Mosquito), HCU crews use any heavy, while the LFS requires Lancasters.  You have a choice of whether to send crews to the LFS or just assign some Lancasters for HCU use — the latter will increase throughput, but tie down more precious Lancs.
The effective skill of a crewman is scaled by the Heavy skill if flying a heavy, and the Lanc skill if flying a Lancaster; a full-length course at both HCU and LFS (or at a Lanc-equipped HCU) will raise both from their starting 20% to 100%.  These skills can also be learned 'on the job'; an operation in the appropriate type of aircraft will raise Heavy skill 10%, and Lanc skill 25%, up to the 100% maximum.

Stations and Squadrons
~~~~~~~~~~~~~~~~~~~~~~
Bombers are organised into Squadrons, with a nominal strength of either twenty (two flights) or thirty (three flights) aircraft on each squadron.  Each squadron operates a single type of bomber (although possibly with a mix of marks); to change to a different type, it must 'convert' which will take it out of operations for a few weeks while the crews train on the new aircraft.  This takes three weeks if converting to a medium, or four if converting to a heavy bomber type.  However, converting from the Manchester to the Lancaster, or from the Halifax to the Halifax III, is simpler and takes only two weeks.  While a squadron is converting (or for any other reason non-operational), its crews will train on their aircraft, albeit more slowly than at dedicated Training Units; this is particularly useful when creating your first heavy-bomber squadrons, as you don't yet have HCUs to train up the Heavy skill.
Squadrons are based at Stations, each of which can hold a maximum of four flights (so, either two two-flight squadrons or a single three-flighter).  A station may operate a mixture of types, but this is inadvisable as the logistical problems (with ground crew, spares etc.) slow down the repair of damaged aircraft and lower both squadrons' serviceability.  A squadron can be 'remustered' to a different station (which has room for it), though it will take a week before they ready to operate from their new home.  A squadron can be disbanded, which will release its aircrews to other squadrons in the Group (see below), and its aircraft for use by any other squadron.
Once your squadrons are full, to grow further you must increase the nominal strength (called Initial Establishment or I.E.), which you can do either by adding a C Flight to an existing two-flight squadron, or by splitting off the C Flight of a three-flight squadron to form the nucleus of a new two-flight squadron.  (In either case there must be room on the Station for the new flight, and at least one available aircraft to add.)  Newly-formed squadrons take one week to become operational, whereas expanding to three flights takes no time.
In 1939 all stations have grass runways, which have two problems: they turn muddy in bad weather (preventing the aircraft based there from flying), and they are inadequate for a heavy bomber with a full war load.  Thus, heavies operating off grass strips will have a reduced range and payload.  From late 1940, you can gradually upgrade your stations, providing them with concrete runways, taxiways, dispersal pans etc., which remove that limitation.  While extremely foul weather (snow, fog) may still 'clamp' paved stations, they are still a considerable improvement.
Stations are collected into Groups, chiefly as an administrative unit.  In 1939 there are Nos. 1 and 5 Groups with bases in Lincolnshire, No. 2 Group in Norfolk, No. 3 Group in Cambridgeshire, and Nos. 4 and 6 Groups in Yorkshire.  Later when Pathfinder Force (No. 8 Group) is formed, some of the stations of Nos. 2 and 3 Groups (with their squadrons, aircraft and crews) will be transferred to the new group.  (You can tell which ones, because they're at the bottom of the station list.)
If a Group operates a mixture of types, it will experience a serviceability penalty, much like a Station.  However, this is rather harder to avoid than in the case of a Station, owing to the much larger size of a Group; it is quite common to have one or two Groups in the process of converting from one type of bomber to another and thus subject to this penalty.
Remustering a Squadron across Group boundaries creates extra administrative headaches, and will take two weeks rather than just one.
The Stations UI allows you to control what kinds of aircrews will be posted to each squadron to fill vacancies.  Once a squadron is selected, there are two rows of buttons for 'Sprogs' (fresh crews out of training units) and 'Veterans' (crews who have completed one tour and are returning for another).  On each, "OTU" refers to crews with no Heavy or Lanc experience, "HCU" to crews with Heavy but no Lanc experience, and "LFS" to crews with Lanc experience.  Note that a crew who flew even a single day of their HCU course on a Lancaster will have nonzero Lanc experience and thus count as LFS-educated.
Drilling deeper, you can select a Flight (A, B or C) to examine it even more closely; information will be shown about each individual aircraft and crewman in the flight.  This information appears in a grid, each column of which represents a single aircraft and its crew.  The Status row shows either 'A' (this aircraft is Assigned to a raid), 'F' (this aircraft has Failed, i.e. is unserviceable, and cannot be used until it is repaired), or '-' (no statuses apply, so the aircraft is available for assignment).  The Mark row shows 'a', 'b', 'c' or 'd' to indicate the first, second, third or fourth mark of the type (so for instance on a Wellington squadron, 'b' would mean Mk Ic while 'd' would mean Mk X.  The Condition row indicates how worn-out the airframe is: 'n' means a brand-new aircraft, '9' means better than 90% (i.e. less than 10% wear), '8' for 80% and so on.  The remaining rows are for the aircrew, and show their overall skill level (as modified by Heavy and Lanc skills if those are applicable to the aircraft type), as a multiple of 10 rounded down (e.g. '7' means at least 70 skill but less than 80).

Navaids
~~~~~~~
Navigational aids help guide your bombers to the target.  There are four different systems: Gee, Oboe, H₂S and G-H.  All except for H₂S are reliant on ground-based transmissions, and thus their range depends on altitude.
When a navaid becomes available, sets will begin to be installed in your bombers.  You can control which type of bomber should receive sets by clicking on the appropriate navaid icon; the selected icon will be highlighted yellow.  Alternatively, by middle-clicking (or ctrl-clicking) on the icon, you can set that type of navaid to be distributed among all your bomber types.  If you wish to store up navaids and not install them in any bombers (perhaps because you are waiting for a new bomber type to arrive), click the navaid icon while holding both Alt and Shift.

Gee
---
Gee gives your bombers a rough 'fix' of their position at ranges up to about 360mi.  It is available from March 1942.  The introduction of GEE also triggers 'bomber stream' tactics: instead of choosing their own routes and times on target, every aircraft is fitted into a large-scale plan.  All aircraft raiding a given target will follow the same route, and they will be timed to bomb from Zero Hour (01:00) until "Zero plus ten" (01:10).  You can change the route by clicking and dragging the turning-points on the map, and you can change the Zero Hour with the spinner in the raid-box.  You can also define up to three 'saved routes' for each target for re-use in later raids.
Later (September 1942) the Germans will jam GEE, reducing the range to 200mi.  Late in December 1942, GEE sets will be plentiful enough that one is installed in every new bomber off the production line.

Oboe
----
Oboe is a precision blind-bombing device.  By its nature a pair of Oboe stations can only be used by one aircraft at once.  The disposition of Oboe stations is made automatically, with priority given to Pathfinders (more precisely, aircraft carrying TIs).  It is invented in November 1941.

H₂S
---
H₂S is a terrain radar.  It enables your bombers to navigate by ground features even in heavy cloud.  It is developed in January 1943.  It is most effective over coastlines and rivers, though forests, hills and even towns can also give good returns.

G-H
---
G-H has not been implemented yet.  When it has, it will provide blind-bombing capability similar to Oboe but without the restriction on concurrent users.  It is available from November 1943.

PFF
~~~
After the 15th of August 1942, some of your bombers can be assigned to the Pathfinder Force (PFF).  They will mark the target, about 5 minutes before Zero Hour, with TIs and incendiaries, in order to direct the bombing of the Main Force.
The Pathfinders consist of the squadrons of No. 8 Group; upon their creation, a number of stations and their squadrons will be transferred from Nos. 2 and 3 Groups.
You probably want to make sure the Pathfinders have the best navigational aids, to make sure they mark the right target and mark it well.

Window
~~~~~~
Window (known today as 'Chaff') is a radio countermeasure: thousands of strips of aluminium foil, dropped from your bombers to confuse the German radars.  [You should be able to tell a diversionary raid to Window more heavily thus making them look like a larger force, but that's not implemented yet.]

Filters
~~~~~~~
Once navaids are available, it's possible to apply filters when adding bombers to, or removing them from, a raid.  These filters are controlled by a row of buttons (one per navaid) which can be set to '+' (only move bombers which HAVE this), blank (don't filter on this) or '-' (only move bombers which DON'T have this).
There is also a set of two-position filters for Marks (see section "Mods and Marks" above).  If none of the Marks are selected, all will be allowed.  Similarly, there are two-position filters for each Group (see section "Stations and Squadrons" above).
These filters allow more complicated raid planning, such as "Use only H₂S-equipped Pathfinders, but all the Main Force whether they have H₂S or not".

Bombloads
~~~~~~~~~
At first, you don't have to decide what bombload to carry, since all targets take high explosive bombs (except Minelaying and Leaflets, obviously).  However, after the Area Bombing Directive of February 1942, you will find that you can choose the bombload for raids on cities.  Mostly you just control the HE/incendiary mix, except for Mosquitos where the choice is between HE and "TIs", target indicator flares.  Another variable is the HC 'blockbuster' bombs.
In general, HE will do more damage than incendiaries (except for a few especially flammable cities: Hamburg, Dresden, Mannheim and Lübeck), but fires from incendiaries will light up the target and help following crews find it.  TIs, brightly coloured flares which burst and cascade over a target, are even more effective in this regard, and are usually dropped by Pathfinder Mosquitoes to provide a clear aiming point for the Main Force.
High Capacity 'blockbuster' bombs are thin-skinned cylinders filled with high explosive.  They are principally blast bombs, and tend to make buildings much more flammable, so ideally you want lots of these early in the raid, followed up by incendiaries later.  This effect lingers for the first few days after a raid, but then repairs to the buildings end it.
Fires and TIs are generally not visible through thick cloud, so Pathfinder aircraft also carry "release-point flares", commonly known as "skymarkers".  These are suspended on parachutes so as to remain above the cloud for several minutes, and are only dropped if the aircraft has a 'fix' from OBOE or H₂S.
The bombloads and their codenames are:
	"Abnormal":	full HE, typically consisting of 1000lb General Purpose medium-capacity bombs.  (Symbol: three small bombs.)
	"Plumduff":	one High-Capacity 4000lb blockbuster (known as a 'cookie'), plus a mixture of 500lb or 1000lb GP and incendiaries.  Stirlings (and Halifaxes until modified in April 1942) cannot carry this load as their bomb bays are too narrow to hold a 'cookie'.  (Symbol: one large bomb, one small bomb, one fire.)  Or for Mosquitoes and Wellingtons, single HC 4000lb blockbuster (Symbol: one large bomb).
	"Usual":	one 4000lb blockbuster (Lancaster/Manchester) or a small amount of GP (others), plus incendiaries.  (Symbol: one large bomb, two fires.)
	"Arson":	full incendiaries, typically in the form of Small Bomb Containers (SBCs) full of 4lb magnesium stick incendiaries, and/or 30lb incendiary bombs.  (Symbol: three fires.)
	"Plumduff-Plus"	(Lancaster only):	one 8000lb or 12000lb blockbuster plus GP.  (Symbol: one large bomb, two small bombs.)
	"Illuminator"	(Mosquito only):	4 × 250lb TI, 8 × 250lb GP, plus several uncoloured flares.  (Symbol: multiple coloured lights.)
	"Half and Half"	(Mosquito only):	Half of these aircraft will carry Illuminator, the other half will carry Plumduff.  (Symbol: multiple coloured lights / one large bomb)
One final note: after the introduction of the Pathfinders (No. 8 Group), their bombloads are controlled independently of other groups.  The selector on the left is for the PFF, that on the right is for the Main Force.

Budget
~~~~~~
The budget decreases by 4% each day, and is increased by successful raids as follows:
Item            Per day   Total
10,000lb bombs     £80    £2000  Note: Bombs dropped on shipping are not counted here, but those dropped on bridges are.
10,000 leaflets     £6     £150
10,000lb mines     £12     £300
Ship sunk         £600   £15000
Bridge destroyed £2000   £50000  Note: multipliers are not applied.
In the above table, the extra column headed "Total" gives the (approximate) total payout, based on the formula for the sum of a geometric progression.  Since the common ratio is 0.96, this is (1/1-0.96) = 25 times the value in the "Per day" column.
Multipliers:
Berlin			x2 (Includes the city itself, Berlin Leaflets, and (after EVENT_LONDON) any industrial target in Berlin)
Specific industrial	x2 (Targets of class "Industry")
Tactical target		x3 (Targets of class "Airfield", "Bridge" or "Road junction")
U-boat industry		x1.2 (Kiel Dockyards; cities Bremen, Kiel, Wilhelmshaven and Rostock; industries of class "U-boats/Shipyards")
Priority target class	x1.2
Priority industry	x1.2
Ignored class/industry	x0.8
These multipliers stack, so for instance a U-boat factory in Berlin will be x4.8 (Berlin * Specific industrial target * U-boat industry = 2 * 2 * 1.2).
The budget is also increased by £2/day for each percentage point of Confidence, and £1/day for each percentage point of Morale.  Thus if both are maxed out, and no operations are being mounted, the budget will stabilise at (£300 * 25 =) £7500/day (except that Confidence will erode over time).
The Air Ministry will from time to time indicate a stronger interest in targets of a given type or industry; these will be shown by the 'Priority' icons (on the left, just below Morale).  Conversely, some target types or industries may be deemed inconsequential and indicated by the 'Ignore' icons.  These priorities affect the budget contributions as shown above in the Multipliers table; they also affect a raid's effect on Confidence.  Note that the Air Ministry frequently changes its mind about its priorities; target type priorities will last around two weeks, while industry priorities will last about a month.
There are also certain achievements which, owing to their propaganda value, will increase Confidence, Morale, and/or your budget the first time they are performed:
* First bombs to fall on Berlin: +1 Morale, +£4000/day budget.
* First Industry target completely destroyed: +2 Confidence, +£14400/day budget.
* First City completely destroyed: +5 Confidence, +£48000/day budget.
* First thousand-bomber raid: +4 Morale, +£30000/day budget.

Reference
~~~~~~~~~

The data files which specify various objects in Harris all live in the folder "dat", and most have a simple 'colon-separated values' format.  The details of each column are given in comments (lines beginning with '#').  Files of textual messages instead consist of marker lines ("==Title of Item==") and paragraphs of manually-wrapped text.
The files are:
 dat/bombers  - details of bomber types (stats, dates)
 dat/events   - dates of various events
 dat/fighters - details of fighter types (stats, dates)
 dat/flak     - details of flak sites (location, strength, dates, etc.)
 dat/ftrbases - details of fighter bases (location, dates)
 dat/intel    - flavour text describing targets
 dat/locations- used to describe locations of events (e.g. aircraft kills)
 dat/mods     - changes to bomber stats at various points in time
 dat/starts   - descriptive text for the startpoint saves
 dat/targets  - details of targets (location, dates, target class, size, etc.)
 dat/texts    - text content of messages to display on events, new a/c types, etc.
Note that changes to most of these files will break save-compatibility if the number of records is changed.

Tutorial
~~~~~~~~
After starting Harris, choose "Quick Start Game" from the main menu.  This will start the game on 3rd September 1939 (the outbreak of war).  The other main menu options are Set Up Game (to start a game at a different point), Load Game (to load from a saved game), and Exit.
Now you are presented with the main 'control center'.  On the left: the date and moon-phase, your bombers, and some misc. info.  In the middle, the map.  On the right, the list of targets.
We'll start with a raid on shipping in the Heligoland Bight.  In the target list, click that name (it should be second from the top).  It should then be highlighted yellow, and a red cross-hair will appear on the map at its location.
But merely selecting a target doesn't mount a raid; we need to assign some bombers to it.  We'll send some Hampdens.  From the bomber list, left-click on the picture of the Handley Page Hampden (it should be third from the top).  This assigns 10 Hampdens to raid the selected target.  You can also add one at a time (right-click instead), or all the remaining unassigned aircraft of this type (middle-click or ctrl+left-click).  If you have a scroll wheel, you can also assign by hovering over the picture and scrolling up (for 10) or down (for 1).
You can also un-assign bombers from a raid; below the map there should be details of the raid on the selected target.  All the same clicks will, on this row, remove bombers from the raid.
Use these controls to assign a total of 24 Hampdens to the raid.  Next, we'll go elsewhere...
At the same time as we're raiding Heligoland, let's also send other bombers out to drop leaflets on the Big City.  Berlin Leaflets should be fourth on the target list; click on it to select it.  You should notice that Heligoland Bight is now highlighted in red to remind us that there's a raid ordered.  There's also a yellow cross-hair on the map.
We'll send some Whitleys and Wellingtons on this leaflet raid.  Assign 20 of each.
Now, try to assign some Blenheims to the raid as well.  You'll notice that nothing happens.  This is because Berlin is beyond the range of Blenheims; they're light bombers and can only carry enough fuel to get about halfway across the map.  This is indicated by the greying-out of the Blenheim's picture.
Now that we've told our bombers where to raid, and in what numbers, we can start the night's action by clicking "Run tonight's raids" (which is just below the list of aircraft on the left).  Immediately the raids will begin.  During the course of the raid, the display consists of the map, with lots of dots travelling across it.  Each dot is an aircraft, and its colour indicates various things about the aircraft it represents.
* A white dot is a bomber on the way to its target.
* A green dot is a bomber which has dropped its bombs and turned for home.
* A cyan dot is a bomber which has turned back early due to malfunction.
* A pale red dot is a bomber which has been damaged by enemy fire.
* A yellow dot is a crashed bomber.
* A bright red dot is an enemy fighter.
* A black dot is a crashed enemy fighter.
Once all your surviving bombers have returned to base, the game moves on to the next screen, "Raid Result Statistics".  This screen tells you how the attack went, how many loads were delivered to each target, details of any losses, and so on.  It's arranged as a table, with a row for each target and a column for each aircraft type.
In the first row, we have Heligoland Bight.  The odds are that we probably didn't hit any ships, so the cell under the Hampden will read
	Dispatched: 24
	Hit Target: 0
If we did score any hits, it might instead look like
	Dispatched: 24
	Hit Target: 2
	Ships sunk: 1
On the next row appear the results of the leaflet raid on Berlin; we'll see how many Whitleys and how many Wellingtons dropped their leaflets in the right place, and how many leaflets that comes to in total.  (Each bomber carries rather a lot of leaflets, so the numbers are quite big.)
On the bottom and right-hand edges of the table is a row and a column of totals, showing the aggregate performance.
Once you've seen enough of these statistics, click the 'Continue' button (at the top).  This will take you back to the control centre, ready to plan the next night's ops.
Now that we're back here, let's point out some more features of this display.  In the list of bomber types, clicking on any of the blue 'i' buttons will show you the corresponding bomber's description and stats (click 'Continue' to return).  Under each name is a line that reads, for example, "54/123".  This means that you have 123 of that aircraft type, of which 54 are serviceable.  You can only send serviceable aircraft on operations; the proportion of aircraft which are serviceable depends on the type.  Also, repeatedly launching large raids every night will tend to reduce serviceability levels; giving the bombers a few nights of rest will allow them to bounce back.
Below these numbers is a row of four buttons, labelled "NONE", "LOW", "MED" and "HIGH".  These select the (relative) priority for production of each type, thereby controlling how much of your budget is spent on building each type of bomber.  However, as well as the limitations of your budget, there are also limits on the maximum production capacity of each type; if you run up against these limits, budget gets stockpiled (rather than spending it on other types).  This is indicated by "P!" appearing to the right of the priority buttons.
Turning to the map in the middle, you will notice that there are large greyed-out areas.  These are cloud formations, and represent the output of the game's weather model (which isn't very sophisticated, and produces somewhat unrealistic results, but it's good enough for gameplay).  Cloud negatively affects bombers' ability to navigate visually, making it harder for them to hit their targets, but also affords some protection from enemy fighters.  It does not, however, affect radionavigation, radar, or barrage flak (none of which rely on visual contact).  It is also worth noting that (owing to prevailing westerly winds) weather patterns tend to travel east, i.e. from left to right.  When planning your raids, remember that the weather will continue to develop after the raid has been launched and throughout its progress.
As you continue to play the game, new technologies and new aircraft types will be developed, and new kinds of target will appear in the list.