Ammunition

References

1. ^ abA missile tank raises Samus's missile capacity by 5.Codenmikstas/metroid-disassembly · “Metroid (USA)”
   How we know

   4349LDBF7:* BEQ +               ;Branch if item is an energy tank.
   4350LDBF9:  LDA #$05            ;
   4351LDBFB:  JSR AddToMaxMissiles        ;($DD97)Increase missile capacity by 5.
   

   In the cartridge (“Metroid (USA)”): bank 7 $DBF7. 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

2. ^ abA new game starts with 99 units of energy, no energy tanks, and 30 of 30 missiles.Codealex-west/M2RoS
   How we know

   20    db $00       ; Samus' equipment
   ⋮
   23    dw $0099     ; Samus' health
   24    dw $0030     ; Samus' max missiles
   25    dw $0030     ; Samus' missiles
   

   9942pickup_missileTank: ;{
   9943    ; Add 10 to max missiles
   9944    ld a, [samusMaxMissilesLow]
   9945    add $10
   9946    daa
   

   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

3. ^ abA missile tank adds 10 to Samus's missile capacity and 10 to her missiles, each capped at 999.Codealex-west/M2RoS
   How we know

   9942pickup_missileTank: ;{
   9943    ; Add 10 to max missiles
   9944    ld a, [samusMaxMissilesLow]
   9945    add $10
   9946    daa
   ⋮
   9950    daa
   ⋮
   9952    ; Clamp max missiles at 999
   ⋮
   9961    ; Add 10 to current missiles
   ⋮
   9963    add $10
   9964    daa
   ⋮
   9968    daa
   ⋮
   9970    ; Clamp current missiles to 999
   

   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

4. ^ abMissiles, super missiles, and power bombs are three separate pools, each with its own tank; each tank instruction adds its argument, 5, to that pool's maximum and its count.CodeInsaneFirebat/sm_disassembly
   How we know

   1496Instruction_PLM_CollectAmmo_MissileTank:
   

   1520Instruction_PLM_CollectAmmo_SuperMissileTank:
   

   1544Instruction_PLM_CollectAmmo_PowerBombTank:
   

   dw Instruction_PLM_CollectAmmo_MissileTank,$0005

   dw Instruction_PLM_CollectAmmo_SuperMissileTank,$0005

   dw Instruction_PLM_CollectAmmo_PowerBombTank,$0005

   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

5. ^Missiles, super missiles, and power bombs each have their own maximum and count, and each tank adds to both: 5 missiles, 2 super missiles, or 2 power bombs on Easy and Normal, and 2, 1, or 1 on Hard, from a start of 0 (mzm/start-energy). Missile tanks stop adding past 50 tanks' worth, 250 missiles, or 100 on Hard (computed). Metroid has missiles only, and its tank adds 5 to both the count and the capacity.Codemetroidret/mzm · nmikstas/metroid-disassembly
   How we know

   520                if (i == ITEM_TYPE_MISSILE)
   ⋮
   522                    if (sNumberOfTanksPerArea[MAX_AMOUNT_OF_AREAS - 1].missile * sTankIncreaseAmount[gDifficulty].missile + sStartingHealthAmmo.missile >= gEquipment.maxMissiles + sTankIncreaseAmount[gDifficulty].missile)
   ⋮
   524                        if (gEquipment.maxMissiles == 0)
   525                            isFirstTank = TRUE;
   ⋮
   527                        gEquipment.maxMissiles += sTankIncreaseAmount[gDifficulty].missile;
   528                        gEquipment.currentMissiles += sTankIncreaseAmount[gDifficulty].missile;
   

   539                else if (i == ITEM_TYPE_SUPER_MISSILE)
   ⋮
   546                        gEquipment.maxSuperMissiles += sTankIncreaseAmount[gDifficulty].superMissile;
   547                        gEquipment.currentSuperMissiles += sTankIncreaseAmount[gDifficulty].superMissile;
   ⋮
   550                else if (i == ITEM_TYPE_POWER_BOMB)
   ⋮
   557                        gEquipment.maxPowerBombs += sTankIncreaseAmount[gDifficulty].powerBomb;
   558                        gEquipment.currentPowerBombs += sTankIncreaseAmount[gDifficulty].powerBomb;
   

   52    [MAX_AMOUNT_OF_AREAS - 1] = {
   53        .energy = 12,
   54        .missile = 50,
   

   67const struct TankList sTankIncreaseAmount[DIFF_COUNT] = {
   68    [DIFF_EASY] = {
   69        .energy = 100,
   70        .missile = 5,
   71        .superMissile = 2,
   72        .powerBomb = 2
   ⋮
   74    [DIFF_NORMAL] = {
   75        .energy = 100,
   76        .missile = 5,
   77        .superMissile = 2,
   78        .powerBomb = 2
   ⋮
   80    [DIFF_HARD] = {
   ⋮
   

   4349LDBF7:* BEQ +               ;Branch if item is an energy tank.
   4350LDBF9:  LDA #$05            ;
   4351LDBFB:  JSR AddToMaxMissiles        ;($DD97)Increase missile capacity by 5.
   

   4635; Adds A to both MissileCount & MaxMissiles, storing the new count
   ⋮
   4641    ADC MissileCount
   ⋮
   4644*   STA MissileCount
   ⋮
   4647    ADC MaxMissiles
   ⋮
   4650*   STA MaxMissiles
   

   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

6. ^Samus has one missile count and one power bomb count, each with a maximum. A missile tank adds 5 to both the missile count and its maximum, unless the maximum would pass 255; a power bomb tank adds 2 to both, up to 254. The missile types the downloads add (super, ice, and diffusion missiles, flags in weaponsStatus) draw on that one count. Zero Mission keeps separate counts for missiles, super missiles, and power bombs, and its missile tank also adds 5, or 2 on Hard.Codemetroidret/mf · metroidret/mzm
   How we know

   258                // Apply tank
   259                if (i == TANK_TYPE_MISSILE)
   ⋮
   261                    if (gEquipment.maxMissiles + MISSILE_INCREASE_AMOUNT <= MAX_MISSILE_AMOUNT)
   ⋮
   263                        gEquipment.maxMissiles += MISSILE_INCREASE_AMOUNT;
   264                        gEquipment.currentMissiles += MISSILE_INCREASE_AMOUNT;
   ⋮
   275                else if (i == TANK_TYPE_POWER_BOMB)
   ⋮
   277                    if (gEquipment.maxPowerBombs + POWER_BOMB_INCREASE_AMOUNT <= MAX_POWER_BOMB_AMOUNT)
   ⋮
   279                        gEquipment.maxPowerBombs += POWER_BOMB_INCREASE_AMOUNT;
   280                        gEquipment.currentPowerBombs += POWER_BOMB_INCREASE_AMOUNT;
   

   241#ifndef REGION_JP
   242#define ENERGY_INCREASE_AMOUNT 100
   243#define MISSILE_INCREASE_AMOUNT 5
   244#define POWER_BOMB_INCREASE_AMOUNT 2
   ⋮
   248// Default 255
   249#define MAX_MISSILE_AMOUNT (51 * MISSILE_INCREASE_AMOUNT)
   250// Default 254
   251#define MAX_POWER_BOMB_AMOUNT (127 * POWER_BOMB_INCREASE_AMOUNT)
   

   42struct Equipment {
   43    u16 currentEnergy;
   44    u16 maxEnergy;
   45    u16 currentMissiles;
   46    u16 maxMissiles;
   47    u8 currentPowerBombs;
   48    u8 maxPowerBombs;
   49    u8 beamStatus;
   50    u8 weaponsStatus;
   

   273#define MBF_NONE 0
   274#define MBF_MISSILES (1 << 0)
   275#define MBF_SUPER_MISSILES (1 << 1)
   276#define MBF_ICE_MISSILES (1 << 2)
   277#define MBF_DIFFUSION_MISSILES (1 << 3)
   ⋮
   280#define MBF_ANY_MISSILE (MBF_MISSILES | MBF_SUPER_MISSILES | MBF_ICE_MISSILES | MBF_DIFFUSION_MISSILES)
   

   16struct Equipment {
   17    u16 maxEnergy;
   18    u16 maxMissiles;
   19    u8 maxSuperMissiles;
   20    u8 maxPowerBombs;
   21    u16 currentEnergy;
   22    u16 currentMissiles;
   23    u8 currentSuperMissiles;
   24    u8 currentPowerBombs;
   

   67const struct TankList sTankIncreaseAmount[DIFF_COUNT] = {
   68    [DIFF_EASY] = {
   69        .energy = 100,
   70        .missile = 5,
   ⋮
   74    [DIFF_NORMAL] = {
   75        .energy = 100,
   76        .missile = 5,
   ⋮
   80    [DIFF_HARD] = {
   81        .energy = 50,
   82        .missile = 2,
   

   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

7. ^In the US build, Event_CommonItemTake gives 15 handgun bullets, 6 shotgun shells, or 6 rifle shells per ammunition pickup, times a multiplier of extraBulletAdjust + 1, which is at least 2 on Easy; healing pickups always give one item. Normal and Hard don't change the count. extraBulletAdjust is an Extra Options setting: the options screen allows 1 plus one step for each of the five low bits set in extraOptionsEnabled, so ×1 to ×6.Codeshdecompilations/silent-hill-decomp
   How we know

   7#define DEFAULT_PICKUP_ITEM_COUNT      1
   8#define HANDGUN_AMMO_PICKUP_ITEM_COUNT 15
   9#define SHOTGUN_AMMO_PICKUP_ITEM_COUNT 6
   10#define RIFLE_AMMO_PICKUP_ITEM_COUNT   6
   

   1104void Event_CommonItemTake(u32 pickupType, e_EventFlag eventFlagIdx) // 0x800879FC
   ⋮
   1106    #define EASY_DIFFICULTY_AMMO_COUNT_MULT_MIN 2
   ⋮
   1111    ammoCountMult = g_GameWork.config.extraBulletAdjust + 1;
   1112    if (g_SavegamePtr->gameDifficulty == GameDifficulty_Easy)
   ⋮
   1114        ammoCountMult = CLAMP(ammoCountMult, EASY_DIFFICULTY_AMMO_COUNT_MULT_MIN, ammoCountMult);
   ⋮
   1121            Event_ItemTake(InvItemId_FirstAidKit, DEFAULT_PICKUP_ITEM_COUNT, eventFlagIdx, MapMsgIdx_FirstAidSelect);
   ⋮
   1133            Event_ItemTake(InvItemId_HandgunBullets, ammoCountMult * HANDGUN_AMMO_PICKUP_ITEM_COUNT, eventFlagIdx, MapMsgIdx_HandgunAmmoSelect);
   ⋮
   1137            Event_ItemTake(InvItemId_ShotgunShells, ammoCountMult * SHOTGUN_AMMO_PICKUP_ITEM_COUNT, eventFlagIdx, MapMsgIdx_ShotgunAmmoSelect);
   ⋮
   1141            Event_ItemTake(InvItemId_RifleShells, ammoCountMult * RIFLE_AMMO_PICKUP_ITEM_COUNT, eventFlagIdx, MapMsgIdx_RifleAmmoSelect);
   

   136            g_ExtraOptionsMenu_BulletMultMax     = 1;
   137            unlockedOptFlags                     = g_GameWork.config.extraOptionsEnabled;
   ⋮
   139            // Set available bullet multiplier.
   140            for (i = 0; i < 5; i++)
   ⋮
   142                if (unlockedOptFlags & (1 << i))
   ⋮
   144                    g_ExtraOptionsMenu_BulletMultMax++;
   

   460                    g_GameWork.config.extraBulletAdjust = g_GameWork.config.extraBulletAdjust + (g_ExtraOptionsMenu_BulletMultMax - 1);
   ⋮
   462                g_GameWork.config.extraBulletAdjust = g_GameWork.config.extraBulletAdjust % g_ExtraOptionsMenu_BulletMultMax;
   

   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

8. ^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.Codemetroidret/mf
   How we know

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

   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;
   ⋮
   

   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;
   

   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