What Pokémon Sour Crystal changes

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

How the game plays

Pokémon Sour Crystal is SourApple's build-upon of Pokémon Crystal, written from the game's own disassembled source code rather than a binary patch. The creator's own words for the project are that it does not set out to change Crystal so much as build on it: all 251 Johto and Kanto Pokémon are still obtainable, the story beats are the ones you remember, and the twelve original gym leaders keep their names — but Kanto is restored to its original Gen 1 size with several HeartGold/SoulSilver routes grafted on, base stats are brought in line with Generation 7, move data and movepools are updated, Ghost is a special type here and Dark and Dragon are physical, catching is friendlier (Apricorn balls work instantly, TMs are reusable, a Pager calls in field moves, so no team slot goes to a Pokémon kept only for an HM), and a whole second difficulty — Challenge Mode — runs alongside the standard game with its own trainer rosters and some of its own wild tables. Over 200 species carry the creator's own redrawn sprites. This guide is generated from the creator's own source tree at tag SC-v7.0a and the documentation spreadsheet linked from the project's own README and FAQ.

The main changes

• All 251 Pokémon obtainable, Johto and Kanto together
• Kanto restored to its original Game Boy size, plus several HeartGold/SoulSilver-only routes
• A full second difficulty, Challenge Mode, with its own trainer rosters (often with held items and EVs) and some of its own wild tables — chosen once, at New Game
• Base stats updated to Generation 7 numbers
• Ghost is a special type here; Dark and Dragon are physical
• Over 200 Pokémon with the creator's own redrawn sprites
• A four-area Johto Safari Zone alongside Kanto's own, plus overworld weather and a day/night cycle
• 95+ wild swarms, each with its own notifier and raised shiny odds
• An upgraded trainer rematch system: ~44 trainers call to rematch across five story checkpoints, and every gym leader, Elite Four member and the Champion take a rematch team once Red is beaten
• Reusable TMs, instant Apricorn balls, a Pager that calls in field moves instead of a Pokémon kept only for its HMs, and trade evolutions that work with a held item (the Linking Cord) instead of a trade

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 Crystal, so a difference here can belong to the series rather than to this hack.

Evolution methods for all 113 species →

Base stat changes (3)

	Pokémon	What changed	Total
	Ledian	Sp. Atk 55→65	390→400
	Slugma	HP 40→50, Defense 40→50, Sp. Def 40→50	250→280
	Magcargo	HP 60→80	430→450

Type changes (13)

	Pokémon	Was	Now
	Clefairy	Fairy	Normal
	Clefable	Fairy	Normal
	Jigglypuff	Normal / Fairy	Normal
	Wigglytuff	Normal / Fairy	Normal
	Mr. Mime	Psychic / Fairy	Psychic
	Cleffa	Fairy	Normal
	Igglybuff	Normal / Fairy	Normal
	Togepi	Fairy	Normal
	Togetic	Fairy / Flying	NormalFlying
	Marill	Water / Fairy	Water
	Azumarill	Water / Fairy	Water
	Snubbull	Fairy	Normal
	Granbull	Fairy	Normal