What Pokémon GS Chronicles changes

How the game plays differently from Pokémon FireRed, then every stat, type and ability it alters next to what the official games do.

How the game plays

Pokémon GS Chronicles is a FireRed hack by Ruki Studios that retells Gold and Silver rather than remaking them: the towns and the badge order are Johto's, the maps take after HeartGold and SoulSilver, and the events around them are the team's own. It runs on a heavily modified Complete FireRed Upgrade, so it carries the physical/special split, the Fairy type, Gen 4–8 moves, Mega Evolution during the main story, a day-and-night cycle with time-based encounters, and a set of PokéRides that stand in for HMs. Build 2.7.6 (June 2024) runs from New Bark Town through the eight Johto gyms to the Pokémon League and stops at the gym rematches; Kanto is promised but not in this build. This guide is built from the team's documentation sheet and their source repository, and says so wherever the two cannot vouch for what a player of 2.7.6 actually sees.

The main changes

• A Johto story rebuilt from scratch with HGSS-style maps, new events and a few new characters
• Mega Evolution in the main story, with 38 Mega Stones the sheet places, and Z-Moves promised for the Kanto post-game
• PokéRides instead of HMs: Bright, Sharp, Crush, Wave, Skydive, Heavy, Whirl, Clamber and Cascade Rides, each picked up along the way
• Day and night encounters, a regional dex of 448 species with 21 of them given new base stats
• 120 TMs, reusable, with 53 of them located so far; 13 move tutors
• 69 documented boss fights through the League and the scaling gym rematches

How the Pokémon change

Measured from the guide's own data, so it can't drift from the pages it links to.

Compared against present-day official data. The Fairy type and hidden abilities arrived after Pokémon FireRed, so a difference here can belong to the series rather than to this hack.

Base stat changes (33)

	Pokémon	What changed	Total
	Bulbasaur	HP 45→0, Attack 49→0, Defense 49→0, Sp. Atk 65→0, Sp. Def 65→0, Speed 45→0	318→0
	Ivysaur	HP 60→0, Attack 62→0, Defense 63→0, Sp. Atk 80→0, Sp. Def 80→0, Speed 60→0	405→0
	Charmander	HP 39→0, Attack 52→0, Defense 43→0, Sp. Atk 60→0, Sp. Def 50→0, Speed 65→0	309→0
	Charizard	HP 78→0, Attack 84→0, Defense 78→0, Sp. Atk 109→0, Sp. Def 85→0, Speed 100→0	534→0
	Squirtle	HP 44→0, Attack 48→0, Defense 65→0, Sp. Atk 50→0, Sp. Def 64→0, Speed 43→0	314→0
	Wartortle	HP 59→0, Attack 63→0, Defense 80→0, Sp. Atk 65→0, Sp. Def 80→0, Speed 58→0	405→0
	Blastoise	HP 79→0, Attack 83→0, Defense 100→0, Sp. Atk 85→0, Sp. Def 105→0, Speed 78→0	530→0
	Ninetales	HP 73→80, Attack 76→67, Defense 75→90, Sp. Atk 81→108, Sp. Def 100→110	505→555
	Farfetch'd	HP 52→72, Attack 90→95, Defense 55→73, Sp. Atk 58→53, Sp. Def 62→87, Speed 60→85	377→465
	Porygon-Z	HP 85→0, Attack 80→0, Defense 70→0, Sp. Atk 135→0, Sp. Def 75→0, Speed 90→0	535→0
	Aerodactyl	HP 80→0, Attack 105→0, Defense 65→0, Sp. Atk 60→0, Sp. Def 75→0, Speed 130→0	515→0
	Meganium	Attack 82→65, Defense 100→74, Sp. Atk 83→125, Sp. Def 100→114, Speed 80→77	525→535
	Ledian	HP 55→80, Attack 35→105, Defense 50→80, Sp. Atk 55→25, Speed 85→100	390→500
	Ariados	HP 70→65, Attack 90→100, Defense 70→65, Sp. Atk 60→100, Sp. Def 70→65, Speed 40→110	400→505
	Xatu	Sp. Atk 95→105, Speed 95→105	470→490
	Ampharos	Speed 55→90	510→545
	Sunflora	HP 75→95, Attack 75→30, Defense 55→110, Sp. Atk 105→110, Sp. Def 85→110, Speed 30→40	425→495
	Forretress	Sp. Atk 60→45, Sp. Def 60→90	465→480
	Granbull	Speed 45→95	450→500
	Qwilfish	Attack 95→105, Defense 85→100, Sp. Atk 55→20, Sp. Def 55→120	440→495
	Ursaring	HP 90→80, Defense 75→110, Sp. Atk 75→50, Sp. Def 75→110	500→535
	Corsola	HP 65→110, Attack 55→95, Defense 95→85, Sp. Atk 65→90, Sp. Def 95→85	410→500
	Stantler	Attack 95→130, Defense 62→97, Sp. Atk 85→35, Sp. Def 65→85, Speed 85→105	465→525
	Delcatty	HP 70→80, Attack 65→120, Defense 65→75, Sp. Atk 55→25, Sp. Def 55→75, Speed 90→110	400→485
	Tropius	HP 99→89, Attack 68→58, Sp. Atk 72→12	460→380
	Luxray	Sp. Atk 95→45, Speed 70→120	523→523
	Bonsly	HP 50→0, Attack 80→0, Defense 95→0, Sp. Atk 10→0, Sp. Def 45→0, Speed 10→0	290→0
	Spiritomb	HP 50→0, Attack 92→0, Defense 108→0, Sp. Atk 92→0, Sp. Def 108→0, Speed 35→0	485→0
	Lumineon	Attack 69→38, Sp. Atk 69→91, Speed 91→100	460→460
	Electivire	Sp. Atk 95→75, Speed 95→115	540→540
	Magmortar	Defense 67→87, Speed 83→63	540→540
	Yanmega	HP 86→85, Attack 76→110, Defense 86→60, Sp. Atk 116→110, Sp. Def 56→60, Speed 95→110	515→535
	Perrserker	HP 70→0, Attack 110→0, Defense 100→0, Sp. Atk 50→0, Sp. Def 60→0, Speed 50→0	440→0

Type changes (10)

	Pokémon	Was	Now
	Ledian	Bug / Flying	BugFighting (N)
	Ariados	Bug / Poison	BugGhost (N)
	Ampharos	Electric	ElectricDragon (N)
	Sunflora	Grass	GrassFire (N)
	Stantler	Normal	NormalPsychic (N)
	Miltank	Normal	NormalFairy
	Combusken	Fire / Fighting	Fire
	Blaziken	Fire / Fighting	Fire
	Yanmega	Bug / Flying	BugDragon (N)
	Gliscor	Ground / Flying	GroundDark (N)

Ability changes (29)

	Pokémon	Gains	Loses
	Pikachu	Lightningrod	Lightning Rod
	Raichu	Lightningrod	Lightning Rod
	Sandshrew	Sand Throw	Sand Rush
	Sandslash	Sand Throw	Sand Rush
	Koffing	Neutralize Gas	Neutralizing Gas, Stench
	Weezing	Neutralize Gas	Neutralizing Gas, Stench
	Goldeen	Lightningrod	Lightning Rod
	Seaking	Lightningrod	Lightning Rod
	Pichu	Lightningrod	Lightning Rod
	Qwilfish	Poison Touch	Poison Point
	Ursaring	—	Quick Feet
	Kingdra	Poison Point	Swift Swim
	Raikou	Volt Absorb	Inner Focus
	Entei	Flash Fire	Inner Focus
	Dustox	Compoundeyes	Compound Eyes
	Shiftry	Early Bird	Wind Rider
	Meditite	Huge Power	Pure Power
	Medicham	Huge Power	Pure Power
	Plusle	—	Lightning Rod
	Minun	—	Volt Absorb
	Kecleon	—	Protean
	Duskull	—	Frisk
	Dusclops	—	Frisk
	Piplup	Defiant	Competitive
	Prinplup	Defiant	Competitive
	Empoleon	Defiant	Competitive
	Starly	—	Reckless
	Gallade	—	Sharpness
	Dusknoir	—	Frisk