ROM Hack — Changelog

Difficulty and progression

×1.5

Level multiplier
(all trainers & wild)

Kanto map bonus
(added before ×1.5)

×3.0

Battle EXP gain
multiplier

Badges to lift
the level cap

⚔️

Hard Mode (always on)

Every battle level — trainers, wild encounters, and scripted fights — is computed as (base + 6 on Kanto) × 1.5, rounded, clamped to 100. The catching tutorial stays at level 5. EXP gains are tripled (3.0×).

🔒

Badge-based Level Cap

Your Pokémon can’t gain EXP past a cap tied to your badge count. After 8 Johto badges (pre-League), the cap locks to Lance’s ace level. Pokémon above the cap simply stop earning EXP. Daycare and Rare Candy obey it too. The cap lifts entirely after all 16 badges.

Hard mode level = (base level + (Kanto? 6 : 0)) × 1.5 → rounded → clamped to 100

Progress (badge count)	Base cap (reference)	Cap after hard mode	Notes
Johto 0	9	14	Applies from start until you earn your 1st Johto badge
Johto 1	16	24
Johto 2	20	30
Johto 3	25	38
Johto 4	30	45
Johto 5	31	47
Johto 6	35	53
Johto 7	40	60	Applies until you earn your 8th Johto badge
Johto 8 (pre-League)	50	75	Applies until you clear the League (Champion Lance ace level)
Kanto 0	60	90	Used after you clear the League, even with 0 Kanto badges
Kanto 1	62	93
Kanto 2	64	96
Kanto 3	66	99
Kanto 4	68	100	Clamp at 100 for higher tiers
Kanto 5	70	100
Kanto 6	72	100
Kanto 7	75	100	Cap removed after you earn all 8 Kanto badges (16 total)

Wild encounters and roaming beasts

🌿

Wild Level Scaling

Grass, surfing, fishing, headbutt trees, Bug-Catching Contest, and most static encounters (Red Gyarados, legendaries, Sudowoodo) all get the Kanto +6 bonus then the ×1.5 multiplier. Snorlax is exempt from the +6 bonus (still gets ×1.5).

⚡

Roaming Beasts

Raikou and Entei: if on the same map as the player, any wild encounter becomes the roamer. They cannot flee on the first turn. Each roam tick gives a 50% chance to stay put. Their levels also scale with Kanto bonus + hard multiplier.

Trainers (before vs after, plus hard-mode result)

6v6

Full teams for
every Gym Leader

Boss trainers
with upgraded rosters

Lv100

All Kanto leaders
cap at max level

All Johto leaders now have 6 Pokémon; Kanto leaders, Blue and Red are also 6. Key ace levels:

Trainer (ace)	Vanilla ace lvl	Hack ace lvl (base)	Hack ace lvl in hard mode
Falkner (Pidgeotto)	9	9	14
Bugsy (Scyther)	16	16	24
Whitney (Miltank)	20	20	30
Morty (Gengar)	25	25	38
Chuck (Poliwrath)	30	30	45
Pryce (Piloswine)	31	31	47
Jasmine (Steelix)	35	35	53
Clair (Kingdra)	40	40	60
Will (Xatu)	42	42	63
Koga (Crobat)	44	44	66
Bruno (Machamp)	46	46	69
Karen (Houndoom)	47	47	71
Lance (Dragonite)	50	50	75
Brock (Tyranitar)	44	72	100 (78×1.5 capped)
Misty (Suicune)	47	70	100 (76×1.5 capped)
Lt. Surge (Raikou)	46	62	100 (68×1.5 capped)
Erika (Celebi)	46	66	100 (72×1.5 capped)
Janine (Muk)	39	64	100 (70×1.5 capped)
Sabrina (Lugia)	48	68	100 (74×1.5 capped)
Blaine (Entei)	50	74	100 (80×1.5 capped)
Blue (Ho-Oh)	58	77	100 (83×1.5 capped)
Red (Mewtwo)	81	88	100 (capped from 132)

Notes:

Hard-mode level = (base level [+6 if the fight is in Kanto]) × 1.5, rounded, then clamped to 100. All Kanto bosses therefore hit the level cap. Red is not in Kanto for the +6, but still caps at 100 after the 1.5× multiplier.
Major battles use a stronger (but non-cheating) trainer AI profile: type-aware move choice, more consistent setup/status logic, aggressive switching, and more decisive item usage.

Trainer Pokémon stat boosts (DVs + Stat Exp) + held items

📊

Before

Trainer Pokémon stats were computed without pulling Stat Exp from the party struct — trainer Stat Exp was effectively 0.

📈

After

Trainer Pokémon now receive class-based DVs + Stat Exp, stats are recomputed at party build, and battle stats are copied from the party struct (the boost actually applies).

Gen 2 terminology: “IVs” = DVs (0–15 per stat), “EVs” = Stat Exp (0–65535 per stat).

Trainer class DVs (before → after) Atk/Def/Spd/Spc · 0–15 each

Trainer class	Before	After
FALKNER	9/10/7/7	11/11/11/11
WHITNEY	8/8/8/8	11/11/11/11
BUGSY	9/8/8/8	11/11/11/11
MORTY	9/8/8/8	12/12/12/12
PRYCE	9/8/8/8	12/12/12/12
JASMINE	9/8/8/8	12/12/12/12
CHUCK	9/8/8/8	12/12/12/12
CLAIR	7/12/13/13	13/13/13/13
WILL	13/12/13/13	13/13/13/13
BRUNO	13/12/13/13	13/13/13/13
KAREN	7/15/13/15	13/13/13/13
KOGA	13/12/13/13	13/13/13/13
CHAMPION	13/12/13/13	15/15/15/15
BROCK	9/8/8/8	13/13/13/13
MISTY	7/8/8/8	13/13/13/13
LT_SURGE	9/8/8/8	13/13/13/13
ERIKA	7/8/8/8	13/13/13/13
JANINE	9/8/8/8	13/13/13/13
SABRINA	7/13/8/7	13/13/13/13
RIVAL2	9/8/8/8	14/14/14/14
BLAINE	9/8/8/8	13/13/13/13
EXECUTIVEM	13/8/10/8	13/13/13/13
EXECUTIVEF	7/14/10/8	13/13/13/13
RED	15/13/13/14	15/15/15/15
BLUE	9/13/13/13	15/15/15/15

Trainer class Stat Exp (EVs) Applied equally to all 5 stats

Stat Exp is applied equally to HP/Atk/Def/Spd/Spc. Tuning knobs: trainer class Stat Exp table + Rival ID scaling.

Trainer class Stat Exp

Stat Exp is applied equally to HP/Atk/Def/Spd/Spc as a big-endian word, where the low byte is always 0: StatExp = (high_byte) × 256.

Tuning knobs: trainer class Stat Exp table + Rival ID scaling.

Trainer class	Stat Exp high byte	Stat Exp per stat
FALKNER	30	7680
WHITNEY	30	7680
BUGSY	30	7680
MORTY	60	15360
PRYCE	60	15360
JASMINE	60	15360
CHUCK	60	15360
CLAIR	80	20480
EXECUTIVEM	100	25600
EXECUTIVEF	100	25600
WILL	120	30720
BRUNO	120	30720
KAREN	120	30720
KOGA	120	30720
CHAMPION	140	35840
BROCK	180	46080
MISTY	180	46080
LT_SURGE	180	46080
ERIKA	180	46080
JANINE	180	46080
SABRINA	180	46080
BLAINE	180	46080
BLUE	200	51200
RED	220	56320

Rival Stat Exp scaling (special-cased by trainer ID)

Rival1: IDs 1–3 → 0; 4–6 → 30; 7–9 → 50; 10–12 → 70; 13–15 → 100
Rival2: IDs 1–3 → 160; 4–6 → 180

Stat Exp impact (rule-of-thumb)

In the Gen 2 stat formula, Stat Exp contributes floor(sqrt(StatExp)) / 4, then scales with level.

High byte	Stat Exp	`isqrt(StatExp)//4`	+stat @ Lv50	+stat @ Lv100
30	7680	21	10	21
60	15360	30	15	30
80	20480	35	17	35
100	25600	40	20	40
120	30720	43	21	43
140	35840	47	23	47
160	40960	50	25	50
180	46080	53	26	53
200	51200	56	28	56
220	56320	59	29	59

Per-stat contributions before the constant +5 (or +Level+10 for HP). Same Stat Exp to all 5 stats, so trainers are “evenly” buffed.

Held items (major battles)

Held items are distinct from trainer-used items (Potions/Full Restores/etc). This section is only about Pokémon-held items.

Before → after

Before: most major battles used TRAINERTYPE_MOVES (so held items were not possible).
After: major battles use TRAINERTYPE_ITEM_MOVES, and many Pokémon carry held items.

Held items used (unique list)

BERRY, BLACKBELT_I, BLACKGLASSES, CHARCOAL, DRAGON_FANG, GOLD_BERRY, HARD_STONE, LEFTOVERS, LIGHT_BALL, MAGNET, METAL_COAT, MINT_BERRY, MIRACLEBERRY, MIRACLE_SEED, MYSTIC_WATER, NEVERMELTICE, PINK_BOW, POISON_BARB, SHARP_BEAK, SILVERPOWDER, SOFT_SAND, SPELL_TAG, TWISTEDSPOON.

Held items are shown directly on the Hack Pokémon cards in the visualizers below (Rival / Rocket / Boss teams). Pokémon without a displayed held item use NO_ITEM.

Trainer AI upgrades (major battles)

Applies to Gym Leaders, Elite Four + Champion, Rival fights, Team Rocket bosses, key Grunts, and endgame bosses (Red/Blue).

Move selection layers

AI_BASIC

Avoids redundant/invalid moves (e.g. status when the target can’t be statused).

AI_SETUP

More willing to use stat boosts and nerfs early in the fight.

AI_TYPES

Avoids immunities and prefers super-effective moves when available.

AI_SMART

Extra context rules for Protect timing, Encore, Perish Song, and more.

AI_OPPORTUNIST

Discourages stalling/setup when the AI is low HP.

AI_AGGRESSIVE + RISKY

Pushes toward higher-damage lines and takes KOs when available.

AI_STATUS

Avoids wasting status moves into immunities (e.g. Toxic into Poison).

🔄

Switching & Items

SWITCH_OFTEN punishes bad matchups and exploits resistances. ALWAYS_USE items: bosses don’t sit on Full Heal/Restore anymore.

🐛

AI Bugfixes (8 fixes)

Mean Look, Conversion2, Sunny Day synergy, Cautious AI, Future Sight, type-matchup reading, item selection loop, and status-heal logic.

Full bugfix details 8 engine-level AI fixes

Fixed Smart AI checks for Mean Look so it keys off the player being badly poisoned (instead of itself).
Fixed Smart AI Conversion2 logic so it doesn’t incorrectly discourage it after the first turn.
Fixed Smart AI Sunny Day synergy so it recognizes SolarBeam / Flame Wheel / Moonlight.
Fixed Cautious AI so it can’t “early return” and fail to discourage residual moves.
Fixed redundant-check for Future Sight so it correctly detects an already-active Future Sight.
Fixed type-matchup reading so AI layers don’t accidentally evaluate matchups with the wrong move type.
Fixed AI item selection loop so it can’t read past the trainer item slots.
Fixed AI status-heal logic so Full Heal/Restore also clears Nightmare + confusion.

Rival battles

🤜

Full Boss Teams

Every Rival fight is 6v6 except the intro fight in Cherrygrove (still 1 Pokémon). Fixed movesets prevent accidental early STAB from level scaling.

📈

Threatening Progression

Zubat→Crobat, Gastly→Gengar, Magnemite→Magneton. Sneasel and Kadabra/Alakazam become core threats by late Johto.

Team Rocket executives

🚀

Full 6v6 Executive Teams

All Rocket Executive battles in Mahogany Hideout and Radio Tower are full boss teams with fixed movesets and held items.

💣

Real Threats

Fake Director mixes Poison/Dark/Flying/Steel staples. Radio Tower boss runs Houndoom with Sunny Day + Solarbeam.

Full teams before/after (levels, moves, held items)

Levels shown are base (pre hard-mode). Kanto fights also get +6 then ×1.5 (cap 100). Compare Vanilla vs Hack rosters below. Held items shown on Hack cards.

Other changes

💰 Economy & Items

Repel prices slashed: Repel 120, Super Repel 170, Max Repel 240.
Evo stones at Celadon Dept Store 4F (¥50,000 each).
Free EXP Share in the PC on a fresh save.

📈 EXP Curves

Many strong Pokémon move from Slow to Medium-Slow growth: Gyarados, Dragonite, Tyranitar, Rhydon, Arcanine, Starmie, Heracross, Skarmory, Houndoom, Snorlax, Lapras, legendaries, and more.

🚲 Quality of Life

Bike works anywhere and stays active across map changes.
Route 17 no longer forces downhill drift.
NPCs stay in place (no random wandering).

⭐ Post-game

After the League, receiving the S.S. Ticket also immediately enables the GS Ball event, without Virtual Console conditions.

💬 Feedback

A clear battle message appears when EXP is blocked by the current level cap, so players know why gains stop.

Evolution changes

All former trade evolutions now trigger on level-up. Held-item requirements stay; the item is consumed on success.

From	To	New trigger	Notes
Kadabra	Alakazam	Level 36	No item needed
Machoke	Machamp	Level 36	No item needed
Graveler	Golem	Level 36	No item needed
Haunter	Gengar	Level 36	No item needed
Poliwhirl	Politoed	Level 36 + King’s Rock	Consumes King’s Rock
Slowpoke	Slowking	Level 37 + King’s Rock	Consumes King’s Rock
Onix	Steelix	Level 37 + Metal Coat	Consumes Metal Coat
Scyther	Scizor	Level 36 + Metal Coat	Consumes Metal Coat
Seadra	Kingdra	Level 40 + Dragon Scale	Consumes Dragon Scale
Porygon	Porygon2	Level 40 + Up-Grade	Consumes Up-Grade