Item drop table

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How it works
Implementations
Compared
Related
Games
References
Sources

An item drop table decides what a defeated enemy leaves behind. A table lists the possible items, and something picks an entry: a counter, a random byte, or both. A chance or a cap decides whether anything drops at all. The Legend of Zelda picks the entry with a counter and the chance with a random byte^1,2. Metroid picks both with one byte that steps once per frame^3,4. A Link to the Past gives each of its seven prize packs its own counter, where Zelda’s groups share one kill cycle^5,6. A pack drops half the time, and pack 4 always⁵.

Metroid Fusion turns a killed enemy into an X parasite whose color comes from a number built from the frame counter and a random value, against three weights in the enemy’s row⁷. The color sets the refill, 10 energy (yellow), 2 missiles (green), 500 energy and 100 missiles (red)⁸. The pick also follows need: a would-be green X turns yellow when missiles are full and energy isn’t⁷, where Metroid caps each room’s drops instead⁹.

Kill cycleThe Legend of Zelda (1986). Four groups, a 10-step kill cycle, and streak bonuses.^{10,1,2,6,11,12,13,14,15,16}
Pack cycleThe Legend of Zelda: A Link to the Past (1991). Seven prize packs, each stepping through its own eight prizes.⁵
Weighted, by needMetroid Fusion (2002). A killed enemy becomes an X parasite whose color, picked from 1024 by per-enemy weights, sets its refill.^7,8
Chance, then setThe Legend of Zelda: Oracle of Seasons and Oracle of Ages (2001). A per-enemy chance from 1 in 16 to always, then one of 32 entries; a drop Link can't use becomes none.¹⁷
One rollMetroid (1986). An 8-entry table read by a frame-stepped byte, capped per room.^{3,18,9,19,20,21,22}

#How it works

on a kill:
    if the enemy never drops: nothing
    entry = TABLE[enemy's group][selector]      # selector: a counter or a random value
    if a guarantee applies:   entry = its item  # streaks, retries
    elif chance fails or cap reached: nothing
    else: drop entry

#Implementations

#The Legend of Zelda (1986)

Zelda sorts monster types into four groups, and seven types never drop¹⁰. Each group has a row of ten items, and a kill cycle that advances with every kill picks the column^1,6. A drop then needs the dead monster’s random byte to be under the group’s rate, 80, 152, 104, and 104 in 256^2,2. Measured in the ROM over every case, the groups drop in 800, 1,520, 1,040, and 1,040 of 2,560¹⁴ cases¹⁴.

Two streak counters override the table. The 10th kill since Link was last hurt guarantees 5 rupees, or bombs if that kill was by bomb, and the 16th guarantees a fairy^12,11. Any hit on Link zeroes both¹³.

#Metroid (1986)

Metroid’s selector is RandomNumber1, which gains 25 once per frame, so a drop depends on the frame the enemy dies⁴. Values below 16 drop nothing; the low 3 bits of the rest pick missiles, energy, or a 20-unit energy ball from an 8-entry table^3,18. The 20-unit ball drops only for enemies that the area’s data allows, and the table’s comment calls it “No item”¹⁸.

Caps replace Zelda’s streaks. Each door re-rolls how many missiles and energy balls the next room may drop, and a drop that would pass its cap is lost⁹. In Tourian, a roll that would drop nothing instead resets the caps and rolls again²¹. Measured over all 256 values for one Brinstar enemy, the code gives 60 missiles, 90 energy balls, 90 $89 balls, and 16 nothing^22,22.

#Compared

	The Legend of Zelda	Metroid
Entries	4 rows of 10, by monster group¹	1 row of 8 for every enemy³
Selector	a kill counter, 0–9⁶	a byte stepped by 25 each frame⁴
Whether anything drops	random byte under a per-group rate²	byte of 16 or more, and the room’s caps^3,9
Guarantees	10th and 16th kill without being hurt^12,11	Tourian re-rolls until something drops²¹
Per-enemy differences	group membership¹⁰	one bit allows the 20-unit ball; one flag makes drops worth 30^18,20

Games

Game	Year	How	Note
The Legend of Zelda	1986	Kill cycle	four groups, a 10-step kill cycle, and streak bonuses
The Legend of Zelda: A Link to the Past	1991	Pack cycle	seven prize packs, each stepping through its own eight prizes
Metroid Fusion	2002	Weighted, by need	a killed enemy becomes an X parasite whose color, picked from 1024 by per-enemy weights, sets its refill
The Legend of Zelda: The Minish Cap	2004	Weighted, by need	per-monster weights, raised for hearts, bombs, arrows, and rupees Link lacks, and one roll
The Legend of Zelda: Oracle of Seasons and Oracle of Ages	2001	Chance, then set	a per-enemy chance from 1 in 16 to always, then one of 32 entries; a drop Link can't use becomes none
Metroid	1986	One roll	an 8-entry table read by a frame-stepped byte, capped per room

Every claim about this mechanic, by game (23)

Metroid 1986	When an enemy dies, a `RandomNumber1` below 16 drops nothing; otherwise its low 3 bits pick from `ItemDropTbl`, which holds a missile at 0 and 3, energy at 1, 4, and 6, and `$89` at 2, 5, and 7.	Code
	Item `$89` drops only for an enemy whose byte in the area's table at `$968B` has bit 0 set, and Samus collects it as 20 units of energy; the table's comment calls it "No item".	Code
	Each door re-rolls the room's caps from `RandomNumber1`, 0 to 15 missile drops and 64 to 94 energy drops, and zeroes the counts. A drop that would pass its cap is lost; one that passes the test adds to its count, even a `$89` roll that the enemy then can't drop.	Code
	Until the first door, the caps on missile and energy drops are 39 when the game starts in Brinstar, because `SamusInit` stores the mirroring value `$27` into them, or 47 (`$2F`) elsewhere.	Code
	A small energy ball gives Samus 5 units and a `$89` ball 20; a missile gives 2 missiles; an enemy whose data index carries the 30-unit flag gives 30 units or 30 missiles instead.	Code
	In Tourian, enemies with data index 2 or 4 drop nothing, and any other kill that would drop nothing resets both caps to 1 and both counts to 0 and rolls the same `RandomNumber1` again, skipping the test for 16.	Code
	Called in the ROM for all 256 values of `RandomNumber1`, the drop code gives a Brinstar enemy of data index 0 60 missiles, 90 small energy balls, 90 `$89` balls, and 16 nothing; index 3, whose byte in the table `LF74B` reads (`$968B` + data index, kept in `$00`) has bit 0 clear, gives 106 nothing and no `$89`.	Verified
The Legend of Zelda 1986	Whenever Link is hurt, the game zeroes `WorldKillCount`, `HelpDropCount`, and `HelpDropValue`, the counters behind the fairy and the 10th-kill drops.	Code
	`SetUpDroppedItem` sorts a dead monster's type into one of four drop groups by three type lists, with every unlisted type in the fourth; seven types, among them the Gels, the Keese, and the Like Like, drop nothing.	Code
	`DropItemTable` holds ten items for each group, and the kill cycle picks the column; group A's row is heart, rupee, heart, rupee, fairy, rupee, heart, heart, rupee, rupee.	Code
	In `TakeItem`, item `$18` is a rupee, `$0F` five rupees, `$22` a heart, `$23` a fairy, `$21` the clock, and `$00` four bombs; a heart restores 1 heart and a fairy 3.	Code
	Outside the special cases, a drop happens only when the dead monster's slot's byte of `Random` is below its group's rate: `$50`, `$98`, `$68`, and `$68`, or 80, 152, 104, and 104 in 256.	Code
	Each kill advances `WorldKillCycle` from 0 to 9 and back to 0 before the drop is chosen, except kills of types `$5D`, `$14`, and `$1C`, which the comments call a Child Gel and a Red Keese.	Code
	When `WorldKillCount`, the kills since Link was last hurt, equals 16 and the monster can drop items, the drop is a fairy, whatever its random byte.	Code
	The 10th kill since Link was last hurt brings a guaranteed drop of 5 rupees, or of bombs when that 10th kill was by bomb, and the count starts again from 0.	Code
	A dropped item lasts 255 decrements of its lifetime, one every other frame, about 510 frames, and Link can't take it until the 16th decrement, about 32 frames.	Code
	Called in Rev 1 for every group, kill-cycle column, and value of the random byte, `SetUpDroppedItem` drops in 800, 1,520, 1,040, and 1,040 of 2,560 cases for groups A to D, each the item its column names; it gives a fairy at a kill count of 16, and 5 rupees or bombs at a help count of 10.	Verified
	The Speed Demos Archive Knowledge Base states that 10 kills without being hit force a 5-rupee drop, or a bomb when the 10th is killed by bomb, and that 16 kills in a row force a fairy, only when the 16th enemy can drop items.	Wiki
The Legend of Zelda: A Link to the Past 1991	A defeated monster's prize pack (1–7) gives a drop half the time, and pack 4 always. Each pack keeps its own counter that steps through 8 prizes in order; pack 1's row is heart, heart, heart, heart, green rupee, heart, heart, green rupee.	Code
The Legend of Zelda: Oracle of Seasons and Oracle of Ages 2001	In both US releases a killed enemy's byte in `itemDropTables` picks a chance and a drop set, and two random values decide the drop. The first picks one bit of a 64-bit chance mask (computed, 1 in 16 to always); the second picks one of the set's 32 entries, which Seasons first maps through a Subrosia set when Link is in Subrosia. A drop Link can't use yet, such as bombs or seeds he hasn't found, becomes no drop. An Octorok drops something 24 times in 64; its set holds 16 hearts, 12 single rupees, and 4 five-rupee pieces.	Code
Metroid Fusion 2002	Touching an absorbable X parasite runs `SamusAbsorbX`, which refills by its color: a red X (`SSC_RED_X_PARASITE`) 500 energy, 100 missiles, and 10 power bombs; a green X 2 missiles; any other (yellow) X 10 energy. `SpriteUtilRefillSamus` adds missiles only once a missile flag is set and power bombs only once the power bomb flag is, and stops each at its maximum.	Code
Metroid Fusion 2002	When a dying sprite's countdown ends, `SpriteDying` sets its pose to 0x5B (the decompilers' `SPRITE_POSE_TURNING_INTO_X`) unless it is a secondary sprite, and an enemy's AI (Choot's, for one) runs `XParasiteInit` in that pose. The X it becomes takes its color from a number from 1 to 1024, made from the low 2 bits of `gSpriteRandomNumber` and the 8-bit frame counter, against three weights in that sprite's row of `sPrimarySpriteStats`: the top red-weight values give red and the next green-weight values green, each only when its weight is above 0, and everything left below the green bound gives yellow, whatever the yellow weight is, unless it is 0, which deletes the X instead. A would-be green X turns yellow when missiles are full and energy isn't, or Samus has no missiles yet; a would-be yellow X turns green when energy is full and missiles aren't. An X from a core X is green when `gSpriteRandomNumber` is below 5 or that energy test holds, and otherwise yellow; an X placed in a room is yellow. All of this applies only to an X whose sprite property is `SSP_X_ABSORBABLE_BY_SAMUS`: one marked `SSP_X_UNABSORBABLE_BY_SAMUS`, or the unnamed `SSP_UNKNOWN_40`, is always yellow, and any other property deletes the X.	Code
The Legend of Zelda: The Minish Cap 2004	When a monster dies, its death effect calls the drop routine with the monster's drop table: 6 for Octoroks, ChuChus, Leevers, and Peahats. Unless the room disables random drops, the routine adds the table's 16 weights to an active Picolyte's row, then adds 5 to the heart weight at 8 health (one heart) or less, 3 to bombs with none carried, 3 to arrows with none, and 1 to the 5-rupee weight at 10 rupees or fewer; a weight below 0 (the tables rule an entry out with −999) counts as 0. One `Random()` value then picks the entry: its bits 24–27 choose where to start, and the value modulo the weights' sum walks the 16 entries from there. Table 6 weighs nothing 73, a green rupee 25, a heart 5, bombs 1, and arrows 1, so with no Picolyte and no need bonus an Octorok drops nothing about 70% of the time (computed). Bombs and arrows drop only once Link has the bag or the bow. A Link to the Past instead steps each prize pack through 8 prizes in order.	Code

References

^ a b c dDropItemTable holds ten items for each group, and the kill cycle picks the column; group A's row is heart, rupee, heart, rupee, fairy, rupee, heart, heart, rupee, rupee.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”

How we know

11057; ID's for items dropped by monsters.
11058; WorldKillCycle addresses the column.
⋮
11060; Monsters are arranged in groups that determine the row.
11061; There are four rows.
⋮
11063DropItemTable:
11064    .BYTE $22, $18, $22, $18, $23, $18, $22, $22
11065    .BYTE $18, $18, $0F, $18, $22, $18, $0F, $22
11066    .BYTE $21, $18, $18, $18, $22, $00, $18, $21
11067    .BYTE $18, $22, $00, $18, $00, $22, $22, $22
11068    .BYTE $23, $18, $22, $23, $22, $22, $22, $18

src/Z_04.asm lines 11057–11068 at 50a1c86 · upstream ↗

11137    LDY $01
11138    LDA DropItemSetBaseOffsets, Y
11139    CLC
11140    ADC WorldKillCycle
11141    TAY
11142    LDA DropItemTable, Y
11143    STA $00                     ; [00] Dropped item ID

src/Z_04.asm lines 11137–11143 at 50a1c86 · upstream ↗

In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4, as in drop-groups. We don't reproduce the bytes.

Checked against the evidence by its author, an AI model, 2026-10-20.

Checked by a second AI model, 2026-10-21.

In the claim ledger

^ a b c d eOutside the special cases, a drop happens only when the dead monster's slot's byte of Random is below its group's rate: $50, $98, $68, and $68, or 80, 152, 104, and 104 in 256.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”
How we know
```
11051; Top drop an item, a random value must be less than the
11052; element for the monster group.
⋮
11054DropItemRates:
11055    .BYTE $50, $98, $68, $68
```
src/Z_04.asm lines 11051–11055 at 50a1c86 · upstream ↗
```
11176@RandomlyCancel:
11177    ; If the random value >= drop item rate for the monster's group,
11178    ; then go destroy the monster.
11179    LDY $01
11180    LDA Random, X
11181    CMP DropItemRates, Y
11182    BCS @DestroyMonster
```
src/Z_04.asm lines 11176–11182 at 50a1c86 · upstream ↗
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4, as in drop-groups. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b c d eWhen an enemy dies, a RandomNumber1 below 16 drops nothing; otherwise its low 3 bits pick from ItemDropTbl, which holds a missile at 0 and 3, energy at 1, 4, and 6, and $89 at 2, 5, and 7.Codenmikstas/metroid-disassembly · “Metroid (USA)”
How we know
```
4575    LDA RandomNumber1
4576    CMP #$10
4577    BCC LDD5B
4578*   AND #$07
4579    TAY
4580    LDA ItemDropTbl,y
4581    STA EnAnimFrame,x
```
Source_Files/Bank07.asm lines 4575–4581 at 4270d57 · upstream ↗
```
4722;The following table determines what, if any, items an enemy will drop when it is killed.
⋮
4724ItemDropTbl:
4725LDE35:  .byte $80           ;Missile.
4726LDE36:  .byte $81           ;Energy.
4727LDE37:  .byte $89           ;No item.
4728LDE38:  .byte $80           ;Missile.
4729LDE39:  .byte $81           ;Energy.
4730LDE3A:  .byte $89           ;No item.
4731LDE3B:  .byte $81           ;Energy.
4732LDE3C:  .byte $89           ;No item.
```
Source_Files/Bank07.asm lines 4722–4732 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 7 $DCFC, the drop code; bank 7 $DE35, ItemDropTbl. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b cThe main loop calls RandomNumbers once per frame, after the frame's work; it adds 5 to RandomNumber1 five times, 25 in all, so the byte steps through all 256 values every 256 frames.Codenmikstas/metroid-disassembly · “Metroid (USA)”
How we know
```
34RandomNumbers:
⋮
37LC002:  LDX #$05                ;
38LC004:* LDA RandomNumber1       ;
39LC006:  CLC                     ;
40LC007:  ADC #$05                ;
41LC009:  STA RandomNumber1       ;2E is increased by #$19 every frame and
⋮
46LC012:  DEX                     ;
47LC013:  BNE -                   ;
```
Source_Files/Bank07.asm lines 34–47 at 4270d57 · upstream ↗
```
170WaitNMIEnd:
⋮
176LC0D3:* JSR RandomNumbers       ;($C000)Update pseudo random numbers.
177LC0D6:  JMP MainLoop            ;($C0BC)Jump to top of subroutine.
```
Source_Files/Bank07.asm lines 170–177 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 7 $C000. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b cA defeated monster's prize pack (1–7) gives a drop half the time, and pack 4 always. Each pack keeps its own counter that steps through 8 prizes in order; pack 1's row is heart, heart, heart, heart, green rupee, heart, heart, green rupee.Codespannerisms/usdasm
How we know
```
24136|06F9B2| JSL GetRandomNumber
⋮
24138|06F9B6| PLY
⋮
24140|06F9B7| AND.w PrizePackRarities,Y
24141|06F9BA| BNE .you_dont_get_a_drop
⋮
24152|06F9C0| ORA.w $0FC7,Y
⋮
24155|06F9C4| LDA.w $0FC7,Y
24156|06F9C7| INC A
24157|06F9C8| AND.b #$07
24158|06F9CA| STA.w $0FC7,Y
⋮
24162|06F9CE| LDA.w PrizePackPrizes,Y
```
bank_06.asm lines 24107–24162 at bcdd96e · upstream ↗
```
24276|06FA5C| db $01 ; pack 1 :  50%
⋮
24279|06FA5F| db $00 ; pack 4 : 100%
```
bank_06.asm lines 24275–24283 at bcdd96e · upstream ↗
```
24307.pack_1
24308|06FA72| db $D8 ; SPRITE D8 - heart
⋮
24312|06FA76| db $D9 ; SPRITE D9 - green rupee
```
bank_06.asm lines 24305–24315 at bcdd96e · upstream ↗
Checked against the evidence by its author, an AI model, 2026-10-21.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b c dEach kill advances WorldKillCycle from 0 to 9 and back to 0 before the drop is chosen, except kills of types $5D, $14, and $1C, which the comments call a Child Gel and a Red Keese.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”
How we know
```
5457    ; Certain objects don't advance the world kill cycle.
5458    CMP #$5D
5459    BEQ @DropItem
5460    CMP #$14                    ; Child Gel
5461    BEQ @DropItem
5462    CMP #$1C                    ; Red Keese
5463    BEQ @DropItem
⋮
5465    ; Advance the world kill cycle (0 to 9).
5466    LDA WorldKillCycle
5467    CLC
5468    ADC #$01
5469    CMP #$0A
⋮
```
src/Z_07.asm lines 5457–5488 at 50a1c86 · upstream ↗
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 7 UpdateMetaObjectEnd, $FC95. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger

^ a b cWhen a dying sprite's countdown ends, SpriteDying sets its pose to 0x5B (the decompilers' SPRITE_POSE_TURNING_INTO_X) unless it is a secondary sprite, and an enemy's AI (Choot's, for one) runs XParasiteInit in that pose. The X it becomes takes its color from a number from 1 to 1024, made from the low 2 bits of gSpriteRandomNumber and the 8-bit frame counter, against three weights in that sprite's row of sPrimarySpriteStats: the top red-weight values give red and the next green-weight values green, each only when its weight is above 0, and everything left below the green bound gives yellow, whatever the yellow weight is, unless it is 0, which deletes the X instead. A would-be green X turns yellow when missiles are full and energy isn't, or Samus has no missiles yet; a would-be yellow X turns green when energy is full and missiles aren't. An X from a core X is green when gSpriteRandomNumber is below 5 or that energy test holds, and otherwise yellow; an X placed in a room is yellow. All of this applies only to an X whose sprite property is SSP_X_ABSORBABLE_BY_SAMUS: one marked SSP_X_UNABSORBABLE_BY_SAMUS, or the unnamed SSP_UNKNOWN_40, is always yellow, and any other property deletes the X.Codemetroidret/mfrevised

How we know

561        case SSP_X_ABSORBABLE_BY_SAMUS:
562            if (type == X_PARASITE_TYPE_FROM_CORE_X)
⋮
564                if (gSpriteRandomNumber < 5 || SpriteUtilCheckEnergyFullAndMissilesNotFull())
⋮
566                    gCurrentSprite.pOam = sXParasiteOam_Green;
567                    gCurrentSprite.samusCollision = SSC_GREEN_X_PARASITE;
⋮
569                else
⋮
571                    gCurrentSprite.pOam = sXParasiteOam_Yellow;

src/x_parasite_util.c lines 561–572 at a6d6187 · upstream ↗

575            else if (type == X_PARASITE_TYPE_FROM_SPRITE)
⋮
577                // Calculate random number between 1 and 1024 inclusive
578                randomNumber = gSpriteRandomNumber & 3;
579                randomNumber <<= 8;
580                randomNumber |= gFrameCounter8Bit;
581                randomNumber++;
⋮
583                yellowXThreshold = sPrimarySpriteStats[spriteId][4];
584                greenXThreshold = sPrimarySpriteStats[spriteId][5];
585                redXThreshold = sPrimarySpriteStats[spriteId][6];
⋮
589                    redXThreshold = 1024 - redXThreshold;
590                    if (randomNumber <= 1024 && randomNumber > redXThreshold)
⋮
598                else
⋮

src/x_parasite_util.c lines 574–655 at a6d6187 · upstream ↗

657        case SSP_X_UNABSORBABLE_BY_SAMUS:
658            gCurrentSprite.invincibilityStunFlashTimer &= 0x7f;
659            gCurrentSprite.pOam = sXParasiteOam_Yellow;
⋮
661            break;
⋮
663        case SSP_UNKNOWN_40:
664            gCurrentSprite.pOam = sXParasiteOam_Yellow;
665            gCurrentSprite.samusCollision = SSC_YELLOW_X_PARASITE;
666            break;
⋮
668        default:
669            gCurrentSprite.status = 0;

src/x_parasite_util.c lines 657–669 at a6d6187 · upstream ↗

509void SpriteDying(void)
⋮
519    if (--gCurrentSprite.work1 == 0)
⋮
521        if (gCurrentSprite.properties & SP_SECONDARY_SPRITE)
⋮
523            gCurrentSprite.status = 0;
⋮
525        else
⋮
527            gCurrentSprite.pose = 0x5b;

src/x_parasite_util.c lines 509–530 at a6d6187 · upstream ↗

328        case 0x57:
329            SpriteDyingInit();
330        case 0x58:
331            SpriteDying();
332            break;
⋮
338            break;
⋮
340        case 0x5b:
341            XParasiteInit();
342            break;

src/sprites_AI/choot.c lines 328–342 at a6d6187 · upstream ↗

477    SPRITE_POSE_TURNING_INTO_X = 0x5B,

include/constants/sprite.h line 477 at a6d6187 · upstream ↗

2746u8 SpriteUtilCheckEnergyFullAndMissilesNotFull(void)
⋮
2748    if (gEquipment.currentEnergy == gEquipment.maxEnergy)
⋮
2750        if (gEquipment.weaponsStatus & MBF_ANY_MISSILE && gEquipment.currentMissiles < gEquipment.maxMissiles)
2751            return TRUE;
⋮
2762u8 SpriteUtilCheckMissilesFullAndEnergyNotFull(void)
⋮
2764    if (!(gEquipment.weaponsStatus & MBF_ANY_MISSILE))
2765        return TRUE;
⋮
2767    if (gEquipment.currentMissiles == gEquipment.maxMissiles && gEquipment.currentEnergy < gEquipment.maxEnergy)
2768        return TRUE;

src/sprite_util.c lines 2746–2770 at a6d6187 · upstream ↗

697        case PSPRITE_X_PARASITE_IN_ROOM:
698        case PSPRITE_X_PARASITE_IN_ROOM_PROXIMITY:
⋮
704            XParasiteDetermineColor(X_PARASITE_TYPE_IN_ROOM, 0);
705            break;
⋮
720            XParasiteDetermineColor(X_PARASITE_TYPE_FROM_CORE_X, 0);
⋮
726            break;
⋮
728        case PSPRITE_X_PARASITE:
729        case PSPRITE_X_PARASITE_AQUA_ZEBESIAN:
730            XParasiteSpawningInit();
731            XParasiteDetermineColor(X_PARASITE_TYPE_FROM_SPRITE, gCurrentSprite.roomSlot);
732            break;
⋮
734        default:
⋮

src/x_parasite_util.c lines 697–737 at a6d6187 · upstream ↗

Checked against the evidence by its author, an AI model, 2026-10-22.

Revised after a check by a second AI model, 2026-10-22.

In the claim ledger

^ a bTouching an absorbable X parasite runs SamusAbsorbX, which refills by its color: a red X (SSC_RED_X_PARASITE) 500 energy, 100 missiles, and 10 power bombs; a green X 2 missiles; any other (yellow) X 10 energy. SpriteUtilRefillSamus adds missiles only once a missile flag is set and power bombs only once the power bomb flag is, and stops each at its maximum.Codemetroidret/mf

How we know

482void XParasiteGettingAbsorbedInit(void)
⋮
497    SamusAbsorbX();

src/x_parasite_util.c lines 482–497 at a6d6187 · upstream ↗

433void SamusAbsorbX(void)
⋮
444        case SSP_X_ABSORBABLE_BY_SAMUS:
445            if (gCurrentSprite.samusCollision == SSC_RED_X_PARASITE)
⋮
447                energy = 500;
448                missiles = 100;
449                powerBombs = 10;
⋮
453            else if (gCurrentSprite.samusCollision == SSC_GREEN_X_PARASITE)
⋮
455                energy = 0;
456                missiles = 2;
457                powerBombs = 0;
⋮
461            else
⋮
463                energy = 10;
⋮

src/x_parasite_util.c lines 433–470 at a6d6187 · upstream ↗

2686void SpriteUtilRefillSamus(u16 energy, u16 missiles, u16 powerBombs)
⋮
2688    gEquipment.currentEnergy += energy;
⋮
2690    if (gEquipment.currentEnergy > gEquipment.maxEnergy)
2691        gEquipment.currentEnergy = gEquipment.maxEnergy;
⋮
2693    if (gEquipment.weaponsStatus & MBF_ANY_MISSILE)
⋮
2695        gEquipment.currentMissiles += missiles;
⋮
2697        if (gEquipment.currentMissiles > gEquipment.maxMissiles)
2698            gEquipment.currentMissiles = gEquipment.maxMissiles;
⋮
2701    if (gEquipment.weaponsStatus & MBF_POWER_BOMBS)
⋮
2703        gEquipment.currentPowerBombs += powerBombs;

src/sprite_util.c lines 2686–2707 at a6d6187 · upstream ↗

Checked against the evidence by its author, an AI model, 2026-10-22.

Checked by a second AI model, 2026-10-22.

In the claim ledger

^ a b c dEach door re-rolls the room's caps from RandomNumber1, 0 to 15 missile drops and 64 to 94 energy drops, and zeroes the counts. A drop that would pass its cap is lost; one that passes the test adds to its count, even a $89 roll that the enemy then can't drop.Codenmikstas/metroid-disassembly · “Metroid (USA)”revised
How we know
```
1381L8B1B:  STA CrntMslePickups     ;
1382L8B1D:  STA CrntEnrgyPickups    ;Reset current missile and energy power-up counters.
1383L8B1F:  LDA RandomNumber1       ;
1384L8B21:  AND #$0F                ;Randomly recalculate max missile pickups(16 max, 0 min).
1385L8B23:  STA MaxMissilePickup    ;
1386L8B25:  ASL                     ;
1387L8B26:  ORA #$40                ;*2 for energy pickups and set bit 6(128 max, 64 min).
1388L8B28:  STA MaxEnergyPickup     ;
```
Source_Files/Bank01.asm lines 1381–1388 at 4270d57 · upstream ↗
```
4584    LDY MaxMissilePickup
4585    CPY CrntMslePickups
4586    BEQ LDD5B
4587    LDA MaxMissiles
4588    BEQ LDD5B
4589    INC CrntMslePickups
⋮
4594    BEQ LDD5B
4595    INC CrntEnrgyPickups
4596    CMP #$89
4597    BNE --
4598    LSR $00
4599    BCS --
```
Source_Files/Bank07.asm lines 4584–4599 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 1 $8B1B-$8B29, the reset in SamusEnterDoor; each area bank has its own copy; bank 7, the drop code. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Revised after a check by a second AI model, 2026-10-21: A withheld $89 drop still counts toward the cap.
In the claim ledger
^ a b cSetUpDroppedItem sorts a dead monster's type into one of four drop groups by three type lists, with every unlisted type in the fourth; seven types, among them the Gels, the Keese, and the Like Like, drop nothing.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”
How we know
```
11030; Types of objects that do not drop items.
⋮
11032NoDropMonsterTypes:
11033    .BYTE $5D, $14, $15, $1B, $1C, $1D, $17
⋮
11035DropItemMonsterTypes0:
11036    .BYTE $07, $08, $0E, $04, $0F, $23
⋮
11038DropItemMonsterTypes1:
11039    .BYTE $21, $22, $0D, $10, $13, $28, $2A, $27
11040    .BYTE $16
⋮
11042DropItemMonsterTypes2:
11043    .BYTE $09, $0A, $03, $01, $12, $06, $0B, $24
11044    .BYTE $30
```
src/Z_04.asm lines 11030–11044 at 50a1c86 · upstream ↗
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4 $B01B, the lists, tables, and SetUpDroppedItem. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b cWhen WorldKillCount, the kills since Link was last hurt, equals 16 and the monster can drop items, the drop is a fairy, whatever its random byte.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”
How we know
```
11145    ; If the global kill count = $10, set the dropped item to a fairy.
11146    LDA #$23
11147    LDY WorldKillCount
11148    CPY #$10
11149    BEQ @SetHelpItem
```
src/Z_04.asm lines 11145–11149 at 50a1c86 · upstream ↗
```
5996HandleMonsterDied:
5997    ; Handle the monster dying.
5998    INC WorldKillCount
```
src/Z_01.asm lines 5996–5998 at 50a1c86 · upstream ↗
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4, as in drop-groups. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger

^ a b cThe 10th kill since Link was last hurt brings a guaranteed drop of 5 rupees, or of bombs when that 10th kill was by bomb, and the count starts again from 0.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”

How we know

6000    ; Increase the help drop counter, if not at max ($A).
6001    LDA HelpDropCount
6002    CMP #$0A
6003    BCS @SetDyingMetastate
6004    INC HelpDropCount
⋮
6006    ; If the help drop counter has reached the max, and damage type = bomb (8);
6007    ; then set [51] HelpDropValue in order to drop a bomb next time.

src/Z_01.asm lines 6000–6007 at 50a1c86 · upstream ↗

11151    ; If help drop counter < $A, then use the dropped item ID as is.
11152    ; But there is a random chance that the item drop will be canceled.
⋮
11157    ; Otherwise, the item will be guaranteed to be made.
11158    ; [51] HelpDropValue determines which kind:
11159    ; - 0:     5 rupees
11160    ; - other: bomb
⋮
11172    STA HelpDropCount
11173    STA HelpDropValue

src/Z_04.asm lines 11151–11173 at 50a1c86 · upstream ↗

In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4, as in drop-groups. We don't reproduce the bytes.

Checked against the evidence by its author, an AI model, 2026-10-20.

Checked by a second AI model, 2026-10-21.

In the claim ledger

^ a bWhenever Link is hurt, the game zeroes WorldKillCount, HelpDropCount, and HelpDropValue, the counters behind the fairy and the 10th-kill drops.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”
How we know
```
5759@ResetHelp:
5760    ; Reset values used in special item drops.
5761    LDA #$00
5762    STA WorldKillCount
5763    STA HelpDropCount
5764    STA HelpDropValue
```
src/Z_01.asm lines 5759–5764 at 50a1c86 · upstream ↗
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 1, as in ring. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b cCalled in Rev 1 for every group, kill-cycle column, and value of the random byte, SetUpDroppedItem drops in 800, 1,520, 1,040, and 1,040 of 2,560 cases for groups A to D, each the item its column names; it gives a fairy at a kill count of 16, and 5 rupees or bombs at a help count of 10.Verified“Legend of Zelda, The (USA) (Rev 1)” · aldonunez/zelda1-disassembly
How we know
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4, the routine and tables the probe calls. We don't reproduce the bytes.
```
11138    LDA DropItemSetBaseOffsets, Y
⋮
11140    ADC WorldKillCycle
⋮
11142    LDA DropItemTable, Y
⋮
11147    LDY WorldKillCount
11148    CPY #$10
⋮
11153    LDA HelpDropCount
11154    CMP #$0A
⋮
11180    LDA Random, X
11181    CMP DropItemRates, Y
11182    BCS @DestroyMonster
```
src/Z_04.asm lines 11070–11201 at 50a1c86 · upstream ↗
Measured by a script in MesenCE 2.2.1 (build 4b8a196), on Legend of Zelda, The (USA) (Rev 1) (SHA-1 4671517d72d0…). It fails if the result disagrees with the claim.
The numbers come from the run; its author, an AI model, checked the script measures what the claim says, 2026-10-25.
Checked by a second AI model, 2026-10-21.
Checked by a second AI model, 2026-10-25.
In the claim ledger

^In TakeItem, item $18 is a rupee, $0F five rupees, $22 a heart, $23 a fairy, $21 the clock, and $00 four bombs; a heart restores 1 heart and a fairy 3.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”

How we know

4318ItemIdToSlot:
4319    .BYTE $01, $00, $00, $00, $06, $05, $04, $04
4320    .BYTE $02, $02, $03, $0D, $09, $0C, $1B, $1C
4321    .BYTE $08, $0A, $0B, $0B, $0E, $0F, $10, $11
4322    .BYTE $16, $17, $18, $1A, $1F, $1D, $1E, $07
4323    .BYTE $07, $15, $19, $14
⋮
4341ItemIdToDescriptor:
4342    .BYTE $14, $21, $22, $23, $01, $01, $21, $22
4343    .BYTE $21, $22, $01, $01, $01, $01, $01, $15
4344    .BYTE $01, $01, $21, $22, $01, $01, $01, $01
4345    .BYTE $11, $11, $10, $01, $01, $01, $01, $11
4346    .BYTE $22, $01, $10, $12

src/Z_01.asm lines 4318–4346 at 50a1c86 · upstream ↗

4540    CPY #$18                    ; Heart container item slot
4541    BEQ @TakeHeartContainer
4542    CPY #$1C                    ; 5 Rupees item slot
4543    BEQ Take5Rupees
4544    CPY #$16                    ; Rupee item slot
4545    BEQ @TakeRupee

src/Z_01.asm lines 4540–4545 at 50a1c86 · upstream ↗

4651TakeHeartsNoSound:
4652    LDA $0A                     ; Move item value in [0A] to [01].
4653    STA $01                     ; [01] holds the number of hearts to add minus 1.

src/Z_01.asm lines 4651–4653 at 50a1c86 · upstream ↗

In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 1 TakeItem through the heart routines, run from RAM at $7370. We don't reproduce the bytes.

Checked against the evidence by its author, an AI model, 2026-10-20.

Checked by a second AI model, 2026-10-21.

In the claim ledger

^A dropped item lasts 255 decrements of its lifetime, one every other frame, about 510 frames, and Link can't take it until the 16th decrement, about 32 frames.Codealdonunez/zelda1-disassembly · “Legend of Zelda, The (USA) (Rev 1)”revised
How we know
```
11206UpdateItem:
11207    ; Every other frame, decrement the item lifetime.
11208    LDA FrameCounter
11209    LSR
11210    BCC :+
11211    DEC Item_ObjItemLifetime, X
⋮
11213    ; If lifetime reached 0, go destroy the object.
11214    LDA Item_ObjItemLifetime, X
11215    BEQ DestroyMonster_Bank4
```
src/Z_04.asm lines 11206–11215 at 50a1c86 · upstream ↗
```
4417    ; [03A8][X] is used to count down the life of the item.
4418    LDA Item_ObjItemLifetime, X
4419    CMP #$F0
4420    BCS L6C28_Exit
```
src/Z_01.asm lines 4416–4420 at 50a1c86 · upstream ↗
In the cartridge (“Legend of Zelda, The (USA) (Rev 1)”): bank 4 UpdateItem, $B0FC. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Revised after a check by a second AI model, 2026-10-21: Pickup is blocked for 16 lifetime decrements, not 15.
In the claim ledger

^In both US releases a killed enemy's byte in itemDropTables picks a chance and a drop set, and two random values decide the drop. The first picks one bit of a 64-bit chance mask (computed, 1 in 16 to always); the second picks one of the set's 32 entries, which Seasons first maps through a Subrosia set when Link is in Subrosia. A drop Link can't use yet, such as bombs or seeds he hasn't found, becomes no drop. An Octorok drops something 24 times in 64; its set holds 16 hearts, 12 single rupees, and 4 five-rupee pieces.CodeStewmath/oracles-disasm

How we know

28	xor a
29	call decideItemDrop
30	jp z,partDelete
31	ld b,PART_ITEM_DROP

object_code/common/parts/enemyDestroyed.s lines 28–31 at 21c924a · upstream ↗

761; Decides what an enemy will drop.
⋮
766decideItemDrop_body:
⋮
780	ld hl,itemDropTables
781	rst_addAToHl
⋮
790	ld hl,itemDropProbabilityTable
⋮
795	call getRandomNumber
796	and $3f
797	call checkFlag
⋮
801	and $1f
802	ld hl,itemDropSetTable
⋮
807	call getRandomNumber
808	and $1f
⋮

code/treasureAndDrops.s lines 761–811 at 21c924a · upstream ↗

814; Checks whether an item drop of a given type can spawn.
⋮
817; @param[out]	c	$ff if item cannot spawn (Link doesn't have it), otherwise the item itself
⋮
819.ifdef ROM_SEASONS
820	; different drop table for subrosia

code/treasureAndDrops.s lines 813–845 at 21c924a · upstream ↗

896;   Byte 1: Value to AND with that variable to check availability; if nonzero, the item
897;           can drop.
898itemDropAvailabilityTable:

code/treasureAndDrops.s lines 894–920 at 21c924a · upstream ↗

421wc608: ; $c608
422; This is always 1. Used as a dummy value in various places?

include/wram.s lines 421–423 at 21c924a · upstream ↗

923; Each entry in this table is a bitset. A random bit is chosen. If the bit is 0, no item drops.
924itemDropProbabilityTable:
⋮
934@probability0:
935@probability1:
⋮
953@probability7:

code/treasureAndDrops.s lines 923–956 at 21c924a · upstream ↗

1061itemDropSetE:

code/treasureAndDrops.s lines 1061–1065 at 21c924a · upstream ↗

1074;   Bits 5-7: Index for itemDropProbabilityTable
1075;   Bits 0-4: Index for itemDropSetTable
1076; Or it can be $ff for no item drop.
1077; Comments show changes in Seasons
1078itemDropTables:
1079.ifdef ROM_AGES

code/treasureAndDrops.s lines 1073–1081 at 21c924a · upstream ↗

1098.else

code/treasureAndDrops.s lines 1098–1100 at 21c924a · upstream ↗

39.define ENEMY_OCTOROK $09

constants/common/enemies.s line 39 at 21c924a · upstream ↗

5	ITEM_DROP_FAIRY                   db ; $00
6	ITEM_DROP_HEART                   db ; $01
7	ITEM_DROP_1_RUPEE                 db ; $02
8	ITEM_DROP_5_RUPEES                db ; $03

constants/common/itemDrops.s lines 4–8 at 21c924a · upstream ↗

Checked against the evidence by its author, an AI model, 2026-10-22.

Checked by a second AI model, 2026-10-22.

In the claim ledger

^ a b c dItem $89 drops only for an enemy whose byte in the area's table at $968B has bit 0 set, and Samus collects it as 20 units of energy; the table's comment calls it "No item".Codenmikstas/metroid-disassembly · “Metroid (USA)”
How we know
```
4592*   LDY MaxEnergyPickup
4593    CPY CrntEnrgyPickups
4594    BEQ LDD5B
4595    INC CrntEnrgyPickups
4596    CMP #$89
4597    BNE --
4598    LSR $00
4599    BCS --
```
Source_Files/Bank07.asm lines 4592–4599 at 4270d57 · upstream ↗
```
8534LF74B:  ldy EnDataIndex,x
8535    lda $968B,y
```
Source_Files/Bank07.asm lines 8534–8535 at 4270d57 · upstream ↗
```
8203    ldy #$00
8204    ldx #$03
8205    pla
8206    bne ++
8207    dex
8208    pla
8209    cmp #$81
8210    bne +
8211    ldx #$00            ;Increase HealthHi by 0.
8212    ldy #$50            ;Increase HealthLo by 5.
⋮
8215    sty HealthLoChange
8216    stx HealthHiChange
```
Source_Files/Bank07.asm lines 8203–8216 at 4270d57 · upstream ↗
```
1878L968B:  .byte $01, $01, $01, $00, $86, $04, $89, $80, $81, $00, $00, $00, $82, $00, $00, $00 
```
Source_Files/Bank01.asm line 1878 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 7 $F483, the pickup code; bank 1 $968B, Brinstar's table. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^Until the first door, the caps on missile and energy drops are 39 when the game starts in Brinstar, because SamusInit stores the mirroring value $27 into them, or 47 ($2F) elsewhere.Codenmikstas/metroid-disassembly · “Metroid (USA)”
How we know
```
1564        LDY #$27
1565        LDA InArea
1566        AND #$0F
1567        BEQ +                   ;Branch if Samus starting in Brinstar.
1568        LSR ScrollDir           ;If not in Brinstar, change scroll direction from left
1569        LDY #$2F                ;to down. and set PPU for horizontal mirroring.
1570      * STY MirrorCntrl         ;
1571        STY MaxMissilePickup
1572        STY MaxEnergyPickup
```
Source_Files/Bank07.asm lines 1564–1572 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 7 SamusInit, $C8D1. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a bA small energy ball gives Samus 5 units and a $89 ball 20; a missile gives 2 missiles; an enemy whose data index carries the 30-unit flag gives 30 units or 30 missiles instead.Codenmikstas/metroid-disassembly · “Metroid (USA)”
How we know
```
8203    ldy #$00
8204    ldx #$03
8205    pla
8206    bne ++
8207    dex
8208    pla
⋮
8210    bne +
⋮
8220PickupMissile:
8221    lda #$02
8222    ldy EnDataIndex,x
8223    beq +
8224    lda #$1E
```
Source_Files/Bank07.asm lines 8203–8224 at 4270d57 · upstream ↗
```
4566    JSR LF74B
4567    STA $00
4568    JSR $80B0
4569    AND #$20
4570    STA EnDataIndex,x
```
Source_Files/Bank07.asm lines 4566–4570 at 4270d57 · upstream ↗
```
89L80B0:  LDY EnDataIndex,X
90L80B3:  LDA $977B,Y
91L80B6:  ASL                     ;*2 
```
Source_Files/Bank01.asm lines 89–91 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 7 $F483, the pickup code. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b cIn Tourian, enemies with data index 2 or 4 drop nothing, and any other kill that would drop nothing resets both caps to 1 and both counts to 0 and rolls the same RandomNumber1 again, skipping the test for 16.Codenmikstas/metroid-disassembly · “Metroid (USA)”
How we know
```
4555LDCFC:  LDA InArea
4556    CMP #$13
4557    BNE +
4558    LDA EnDataIndex,x
4559    CMP #$04
4560    BEQ +++++
4561    CMP #$02
4562    BEQ +++++
```
Source_Files/Bank07.asm lines 4555–4562 at 4270d57 · upstream ↗
```
4601LDD5B:  ldx PageIndex
4602    lda InArea
4603    cmp #$13
4604    beq ++
4605*   jmp KillObject          ;($FA18)Free enemy data slot.
⋮
4607*   lda RandomNumber1
4608    ldy #$00
4609    sty CrntEnrgyPickups
4610    sty CrntMslePickups
4611    iny
4612    sty MaxMissilePickup
4613    sty MaxEnergyPickup
⋮
```
Source_Files/Bank07.asm lines 4601–4614 at 4270d57 · upstream ↗
In the cartridge (“Metroid (USA)”): bank 7, the drop code. We don't reproduce the bytes.
Checked against the evidence by its author, an AI model, 2026-10-20.
Checked by a second AI model, 2026-10-21.
In the claim ledger
^ a b cCalled in the ROM for all 256 values of RandomNumber1, the drop code gives a Brinstar enemy of data index 0 60 missiles, 90 small energy balls, 90 $89 balls, and 16 nothing; index 3, whose byte in the table LF74B reads ($968B + data index, kept in $00) has bit 0 clear, gives 106 nothing and no $89.Verified“Metroid (USA)” · nmikstas/metroid-disassemblyrevised
How we know
In the cartridge (“Metroid (USA)”): bank 7 $DCFC, the code the probe calls with Brinstar's bank mapped. We don't reproduce the bytes.
```
4566    JSR LF74B
4567    STA $00
⋮
4575    LDA RandomNumber1
4576    CMP #$10
4577    BCC LDD5B
4578*   AND #$07
4579    TAY
4580    LDA ItemDropTbl,y
⋮
4596    CMP #$89
4597    BNE --
4598    LSR $00
4599    BCS --
```
Source_Files/Bank07.asm lines 4555–4614 at 4270d57 · upstream ↗
```
8535    lda $968B,y
8536    rts
```
Source_Files/Bank07.asm lines 8534–8536 at 4270d57 · upstream ↗
Measured by a script in MesenCE 2.2.1 (build 4b8a196), on Metroid (USA) (SHA-1 2080059bea45…). It fails if the result disagrees with the claim.
The numbers come from the run; its author, an AI model, checked the script measures what the claim says, 2026-10-25.
Checked by a second AI model, 2026-10-21.
Revised after a check by a second AI model, 2026-10-25.
In the claim ledger

Sources

Code

Núñez, Aldo. 2021. “zelda1-disassembly: A complete disassembly of The Legend of Zelda.” Commit 50a1c86. aldonunez/zelda1-disassembly @ 50a1c86 · licence, all uses
n.d. “Legend of Zelda, The (USA) (Rev 1).” · licence, all uses
nmikstas and Kent Hansen. 2025. “metroid-disassembly: Metroid software disassembly.” Commit 4270d57. nmikstas/metroid-disassembly @ 4270d57 · licence, all uses
n.d. “Metroid (USA).” · licence, all uses
(spannerisms), kan. 2026. “usdasm: A Link to the Past US Disassembly.” Commit bcdd96e. spannerisms/usdasm @ bcdd96e · licence, all uses
metroidret contributors. 2026. “mf: a decompilation of Metroid Fusion (metroidret/mf).” Commit a6d6187. metroidret/mf @ a6d6187 · licence, all uses

#How it works

#Implementations

#The Legend of Zelda (1986)

#Metroid (1986)

#Compared

Related

Builds on

See also

Mentioned in

Games

References

Sources

Code