GEN

The lump with the extension .GEN is a critical one. It contains miscellaneous information about a wide variety of unrelated things, especially max number of records for other files, password information, and other stuff that I felt like sticking in there too-- some of which really don't belong.

New general options are increasingly being added to general.reld instead, the RELOAD-format alternative.

This lump is stored in BSAVE format. It has a 7 byte header which indicates the size of the remaining data (and other things). See BSAVE Header for more information.

The .gen lump is normally 1007 bytes long (including 7 byte header). NOTE: The fixWipeGEN fixbit must be checked when reading values at offsets 199 and up.

The following is the meaning of each element.

Grey fields are obsolete or unused.

Pink fields are runtime-only fields used by GAME that do not really belong GEN in the first place, but are there anyway to make including them in SAV files more convenient, which is now a moot argument because of the conversion to RSAV.

Blue fields are editor-only fields used by CUSTOM (although some of them, like 39 genMaxTextbox may be used by GAME for error-checking)

Green records are preserved in RSAV files.

About Formal Specs

Element	Data	Constant	Meaning
0	INT	genMaxMap	max maps
1	INT	genTitle	title screen backdrop index in MXS
2	INT	genTitleMus	title music
3	INT	genVictMus	victory music + 1 (0 for none)
4	INT	genBatMus	default battle music
5	INT	genPassVersion	passcode format number
6	INT	genPW3Rot	old (third-style) passcode rotator
7-15	BYTE*17 + 1		old (third-style) obfuscated passcode + 1 unused byte
16-25	INT*10		ancient (first-style) obsolete password data
26	INT	genMaxHeroPic	max hero graphics in PT0
27	INT	genMaxEnemy1Pic	max small enemy graphics in PT1
28	INT	genMaxEnemy2Pic	max med enemy graphics in PT2
29	INT	genMaxEnemy3Pic	max large graphics in PT3
30	INT	genMaxNPCPic	max npc graphics in PT4
31	INT	genMaxWeaponPic	max weapon graphics in PT5
32	INT	genMaxAttackPic	max attack graphics in PT6
33	INT	genMaxTile	max tilesets in TIL
34	INT	genMaxAttack	max attack definitions in DT6
35	INT	genMaxHero	max hero definitions in DT0
36	INT	genMaxEnemy	max enemy definitions in DT1
37	INT	genMaxFormation	max formations in FOR
38	INT	genMaxPal	max palettes in PAL
39	INT	genMaxTextbox	max text boxes in SAY
40	INT	genMaxPlotscript	total available plotscripts (number of records in PLOTSCR.LST)
41	INT	genNewgameScript	ID of new-game plotscript
42	INT	genGameoverScript	ID of game-over plotscript
43	INT	genMaxRegularScript	ID of highest manually numbered old-style plotscript
44	INT	genSuspendBits	suspendstuff bits: 0 - suspendnpcs 1 - suspendplayer 2 - suspendobstruction 3 - suspendherowalls 4 - suspendnpcwalls 5 - suspendcatapillar 6 - suspendrandomenemies 7 - suspendboxadvance 8 - suspendoverlay 9 - suspendambientmusic
45	INT	genCamera	camera mode
46	INT	genCamArg1	cameraarg1
47	INT	genCamArg2	cameraarg2
48	INT	genCamArg3	cameraarg3
49	INT	genCamArg4	cameraarg4
50	INT	genScrBackdrop	currently displaying script backdrop index in MXS
51	INT	genDays	days of play
52	INT	genHours	hours of play
53	INT	genMinutes	minutes of play
54	INT	genSeconds	seconds of play
55	INT	genMaxVehicle	max vehicle types in VEH
56	INT	genMaxTagname	Last named tag
57	INT	genLoadgameScript	load-game plotscript
58	INT	genTextboxBackdrop	currently displaying text box backdrop in MXS
59	INT	genEnemyDissolve	Default enemy dissolve type. See dissolve types in DT1 (each dissolve type is numbered one less than it is in DT1, for example Random Pixels is 0.
60	INT	genJoy	Enable/disable joystick
61	INT	genPoisonChar	Posion status indicator char (default to 161 if 0)
62	INT	genStunChar	Stun status indicator char (default to 159 if 0)
63	INT	genDamageCap	Damage cap (0 if there is none)
64	INT	genMuteChar	Mute status indicator char (default to 163 if 0)
65-76	INT*12	genStatCap	Stat caps for each stat, in this order: HP MP Atk Aim Def Dog Mag Wil Spd Ctr Focus Extra Hits
77	INT	genMaxSFX	Number of sound effects
78	INT	genMasterPal	Master palette number in PALETTES.BIN
79	INT	genMaxMasterPal	Max master palette number in PALETTES.BIN and number of UI color sets in UICOLORS.BIN
80	INT	genMaxMenu	Max menu in MENUS.BIN
81	INT	genMaxMenuItem	Max menu item in MENUITEM.BIN
82	INT	genMaxItem	Max item number in ITM
83	INT	genMaxBoxBorder	Max box boder pictures in PT7
84	INT	genMaxPortrait	Max portrait graphics in PT8
85	INT	genMaxInventory	Max available inventory slots. 599 is current default max. Gets rounded up to the next multiple of 3 slots (counting the zeroth slot). Zero uses the default max of 599 (600 counting zero)
86	INT	genErrorLevel	Error suppression level: 0: default to 4 2: show all warnings 3: suppress some warnings 4: suppress warnings from weak type checking 5: don't show errors not displayed in old versions 6: show only errors about corruption or interpreter problems
87	INT	genLevelCap	Maximum hero level (0-genMaxLevel) (Unlike genMaxLevel, this can be changed with scripting, and has no effect on stat growth)
88	INT	genEquipMergeFormula	Function used to calculate total hero elemental resistances from equipment: 0: Awful compatible formula 1: Multiplicative 2: Additive
89	INT	genNumElements	Number of elements which the game uses, up to 64 (any higher numbered ones should be ignored in-game)
90	INT	genUnlockedReserveXP	Experience gained by unlocked reserve heroes, as a % of that given to active party heroes
91	INT	genLockedReserveXP	Experience gained by locked reserve heroes, as a % of that given to active party heroes
92	INT	genPW4Hash	Hashed password, 0 if none
93	INT	genPW2Offset	old(second-style) passcode offset
94	INT	genPW2Length	old(second-style) passcode length (-1 if there is no password)
95	INT	genVersion	RPG file format version ID (For latest version see compat.bi. See also Incrementing the RPG format version number)
96	INT	genStartMoney	starting money
97	INT	genMaxShop	last shop in SHO
98	INT	genPW1Offset	old-old(first-style) passcode offset
99	INT	genPW1Length	old-old(first-style) passcode length
100	INT	genNumBackdrops	number of screens in MXS
101	INT	genBits	general bitsets: 0 - Pause in battle on spell and item menus 1 - Enable Caterpillar party 2 - don't restore HP on level-up 3 - don't restore MP on level-up 4 - Inns don't revive dead heros 5 - Hero swapping always available 6 - Hide ready meter in battle 7 - Hide health bar in battle 8 - disable debugging keys 9 - Simulate old level-up bug 10 - Permit double-triggering of scripts 11 - Skip title screen 12 - Skip load screen 13 - Pause in battle on all menus 14 - Disable Hero's Battle Cursor 15 - Default passability disabled by default
102	INT	genStartX	starting X
103	INT	genStartY	starting Y
104	INT	genStartMap	starting Map
105	INT	genOneTimeNPC	one-time-NPC indexer
106-170	INT*65	genOneTimeNPCBits	one-time-NPC placeholder bits. there are 0-1039 bits, but savegames store 0-1031 and the NPC editor only allows 0-1000
171	INT	genDefaultDeathSfx	Default enemy death sound effect ID + 1 (0 for none)
172	INT	genMaxSong	last song number (SNG and BAM)
173	INT	genAcceptSfx	Sound effect to use for "accept" (in menus) ID + 1 (0 for none)
174	INT	genCancelSfx	Sound effect to use for "cancel" (in menus) ID + 1 (0 for none)
175	INT	genChooseSfx	Sound effect to use for moving the cursor (in menus) ID + 1 (0 for none)
176	INT	gentextboxLetter	Sound effect to use for displaying text box lines ID + 1 (0 for none)
177-178	INT*2	genBits2	Additional general bitsets 0 - Simulate pushable NPC collision bug 1 - Disable ESC to run from battle 2 - Don't save gameover/loadgame script IDs (actually prevents using the stored "game over" or "loadgame" script ID number in preference to the ones specified by gen(genGameoverScript) and gen(genLoadgameScript)) 3 - Dead heroes gain share of experience 4 - Locked heros can't be rearranged 5 - Attack captions pause battle meters 6 - Don't randomize battle ready-meters 7 - Battle menus wait for attack animations 8 - Enable better scancodes for scripts 9 - Simulate old fail vs. elemental resist bit 10 - 0 damage when immune to attack elements 11 - Recreate map slices when changing maps 12 - Harm tiles harm non-caterpillar heroes 13 - Attacks ignore extra hits by default 14 - Don't divide experience between heroes 15 - Don't reset max stats after OOB attack 16 - Don't limit max tags to 1000 17 - Enable bug 430 18 - showtextbox happens immediately 19 - Pause battle while targeting attacks 20 - Old attack positioning at bottom-left of target 21 - Wrap map layers over edge of Crop maps 22 - Never show script timer during battles 23 - Draw Backdrop slice above Script layer
179	INT	genItemLearnSFX	Sound effect when learning a spell from an item. ID + 1 (0 for none)
180	INT	genCantLearnSFX	Sound effect when a hero couldn't learn spell from item. ID + 1 (0 for none)
181	INT	genBuySFX	Sound effect when buying an item from a shop. ID + 1 (0 for none)
182	INT	genHireSFX	Sound effect when hiring a hero from a shop. ID + 1 (0 for none)
183	INT	genSellSFX	Sound effect when selling an item to a shop. ID + 1 (0 for none)
184	INT	genCantBuySFX	Sound effect when you can't afford item/hire. ID + 1 (0 for none)
185	INT	genCantSellSFX	Sound effect when trying to sell an unsellable item. ID + 1 (0 for none)
186	INT	genDamageDisplayTicks	Number of ticks to display damage numbers in battle (default 7)
187	INT	genDamageDisplayRise	Number of pixels the displayed damage should rise (default 14)
188	INT	genHeroWeakHP	% HP threshold for hero weak state (default to 20 if 0)
189	INT	genEnemyWeakHP	% HP threshold for enemy weak state (default to 20 if 0)
190	INT	genAutosortScheme	Method of autosorting inventory: 0 - by item type 1 - into usable/not usable 2 - alphabetically 3 - by ID number 4 - no reordering beyond compacting
191	INT	genMaxLevel	Maximum level (0-99) This is the unchanging maximum allowed level for heroes. it is used in the hero stats editor. (Not to be confused with genLevelCap)
192	INT	genBattleMode	Battle mode 0=Active-time, 1=Turn-based
193	INT	genItemStackSize	Default maximum size of an inventory stack
194	INT	genResolutionX	Width in pixels of the game screen (not including graphics backend scaling) or 0 for default, 320x200
195	INT	genResolutionY	Height in pixels of the game screen (see above).
196	INT	genEscMenuScript	plotscript to run when pressing ESC or ALT to open the menu (if zero, just open the menu)
197	INT	genSaveSlotCount	The number of available save slots, 1 to 32. If 0, the default of 4 will be used.
198	INT	genMillisecPerFrame	Number of milliseconds per frame, or 55 if zero.
199	INT	genStealSuccessSFX	ID+1 of sound effect to play for a successful item steal attack, or zero for none.
200	INT	genStealFailSFX	ID+1 of sound effect to play for an unsuccessful item steal attack, or zero for none.
201	INT	genStealNoItemSFX	ID+1 of sound effect to play for an item steal attack with nothing to steal, or zero for none.
202	INT	genRegenChar	Regen status indicator char (default to 32 if 0).
203	INT	genDefaultScale	(Obsolete). For a short while, contained the default scale/zoom factor of the display (1-16), or zero for whatever default is suitable.
204	INT	genDebugMode	0=Release mode, script errors hidden, 1=Debug mode, script errors shown. This setting is editable, and is used as the base for genCurrentDebugMode
205	INT	genCurrentDebugMode	0=Release mode, script errors hidden, 1=Debug mode, script errors shown. This is not directly editable. It is set based on genDebugMode but may be temporarily modified by the "Distribute Game" menu or the "Test Game" feature
206	INT	genStartHero	ID number the initial hero when starting a new game.
207	INT	genStartTextbox	ID number a textbox to open when starting a new game, 0 means none.
208	INT	genWindowSize	Default window size about X% of screen, in multiples of 10% (1-10). 10 means maximize. If 0, default to 8.
209	INT	genLivePreviewWindowSize	Test-Game default window size about X% of screen, in multiples of 10%. 10 means maximize. If 0, default to 5.
210	INT	genFullscreen	If 1 (or nonzero), default to fullscreen if there is no remembered preference for this game from previous plays.
211	INT	genMusicVolume	Initial music volume as a percentage (Needs initialising if fixInitDefaultVolumes false) (This is a WIP feature)
212	INT	genSFXVolume	Initial global sound effects volume as a percentage (Needs initialising if fixInitDefaultVolumes false) (This is a WIP feature)
213-499	INT		unused space

Maximums : "max XYZ" means 'the highest numbered XYZ'. If you have 80 enemies defined, then "max enemy" == 79, because the numbering starts from 0.

Passwords

The password protection in the RPG format is necessarily wet-paper-bag weak, due to the GNU GPL licensing of the engine. RPG password protection works entirely on the honor system. It's kinda like that faded sign hanging on the gates of Anhk-Morpork that says "Thank you for not invading our city"

Here is how to read the password. Please-please-pretty-please dont just ignore it. It is flimsy pathetic laughable protection, but its all we have! Dont take away our wire umbrella in the lightening storm!

Over time there have been 4 different password formats, referred to as PW1, PW2, PW3, PW4. All are stored in the GEN lump. The format is determined by looking at genVersion and genPassVersion (go down this table):

Format	Indicator	Introduced	Last used
PW4	gen(genPassVersion) = 257	pre-Zenzizenzic (Dec 28 2010)	Still in use.
PW3	gen(genPassVersion) = 256	Ozarks (June 28 2004)	Still partial back-compat (see below)
PW2	gen(genVersion) >= 3	June 18 1999	Written until Dec 28 2010
PW1	Otherwise	Stone Age

For backwards compatibility, Custom also writes a blank PW3 password is there is no password, or a random PW3 password if there is one.

The easiest thing to do when decoding an RPG file that still has its password in an old format is to print a warning message telling the user to upgrade their RPG file with CUSTOM.EXE

PW4

This new format stores just a 9-bit hash of the password, in gen(genPW4Hash), so that it is not retrievable.

The hash is calculated as follows (or see common.bas for the FB version):

unsigned short passwordhash (char *p) {
  if (strlen(p) == 0) return 0;
  unsigned int hash = 0;
  while (*p)
    hash = hash * 3 + *p++ * 31;
  return (hash & 511) | 512;
}

PW3

In this format, the password is obscured with weak, but space-wasting encryption, and the length of the password is totally unprotected.

GEN(6) is the password rotator. It will always be a random number from 1 to 254 that will be used to ascii-rotate/obfuscate the password.

GEN(7-15) is the password text. There are 17 bytes of data here (so the high byte of GEN(15) is unused). Read this string of 17 bytes. ascii-rotate each character by subtracting GEN(6) and if the result is < 0 then add 255, and then discard all characters with ascii values less than 32 (space). The resulting string will be your password. If the string is empty (all 17 chars were under 32) then the RPG file does not have a password.

PW2

This information describes the obsolete scattertable-based password storage format. It is only here as a curiosity... and a monument of shame to security-through-obscurity. The body of the scattertable lived at GEN(200) to GEN(359), with the "scattertable head" at gen(199). The first element of the password mess GEN(200) is the bit-offset of the first bit in the password, relative to the beginning of the scattertable head (199). The next element (201) is the bit-offset of the next bit in the password, and so on. So GEN(200) thru GEN(207) will give you the bits that make up the first ascii char of the password. GEN(208)-GEN(215) gives you the next char, and so on up to GEN(94)+1 bytes. After you have read all the chars from the scattertable, rotate them down by the value of GEN(93) (that is to say, subtract GEN(93) from the ascii value of each char, and if the result is less than 0, add 256).

Clear as mud, right? Here is an example. Lets suppose that the data in the GEN lump looks like this

GEN(93)=172    the ascii-rotate offset
GEN(94)=23     the number of bits -1.
               23+1 = 24, thats the total number of bits in the password
               There are 8 bits in each char of the password, so 24
               divided by 8 is 3. That means this password will end up being 3 chars long.
 
BIT OFFSETS/SCATTERTABLE
GEN(199)=8 [0001 0000 0000 0000] dummy number. Never 0 or 255
GEN(200)=4 [0010 0000 0000 0000] Start here. bit 4 in the table is a 0
GEN(201)=3 [1100 0000 0000 0000] bit 3 in the table is a 1, now we have 01
GEN(202)=18[0100 1000 0000 0000] bit 18 is 1: 011
GEN(203)=18[0100 1000 0000 0000] bit 18 is 1: 0111
GEN(204)=54[0110 1100 0000 0000] bit 58 is 0: 01110
GEN(205)=33[1000 0010 0000 0000] bit 33 is 1: 011101
GEN(206)=85[1010 1010 0000 0000] bit 85 is 1: 0111011
GEN(207)=82[0100 1010 0000 0000] bit 82 is 1: 01110111

So we end up with 01110111 which is char 238, (a wierd ascii math symbol) Now we subtract the value of GEN(93) and we get 66, which is the ascii code for upper case B, so we know the first letter of the password is B.

Ah, what fun. what a mess. what a waste. *sigh*

See Also

• Garbage in GEN, an investigation of junk in high areas of GEN in older games

List of other Lumps in the RPG file format

ARCHINYM.LMP . ATTACK.BIN . BINSIZE.BIN . BROWSE.TXT . DEFPAL#.BIN . DEFPASS.BIN . distrib.reld . FIXBITS.BIN . heroes.reld . heroform.reld . LOOKUP1.BIN . MENUS.BIN . MENUITEM.BIN . PALETTES.BIN . PLOTSCR.LST . SFXDATA.BIN . slicetree_#_#.reld . SLICELOOKUP.TXT . SONGDATA.BIN . UICOLORS.BIN . GEN . general.reld . BAM . Map Format . T . P . E . D . L . N . Z . DOR . DOX . DT0 . DT1 . DT6 . EFS . FOR . FNT . HSP . HSZ . ITM . MAP . MAS . MN . MXS . PAL . PT0 . PT1 . PT2 . PT3 . PT4 . PT5 . PT6 . PT7 . PT8 . SAY . SHO . SNG . STF . STT . TAP . TIL . TMN . VEH

List of other OHRRPGCE file formats

RELOAD . RSAV . SAV . ohrkey . gameconfig.ini . persist.reld