Differences From Vanilla

Heart & Soul begins with the broad shape of a Johto adventure, then gets considerably less interested in leaving you alone with 2001-era friction. This is the practical version of what changes from vanilla Crystal: the systems you will actually feel while playing, and the settings that can turn the whole run sideways if you click through them too quickly.

First thing first: choose your run before starting. The challenge menu can be reopened from a PC, but Nuzlocke, randomizer, difficulty, and challenge settings generally only move in the easier direction after the save exists. A few options are exceptions; see Features, Settings & Challenge Modes.

The shape of the game

Heart & Soul keeps the Johto journey and adds a Kanto postgame, with familiar Johto story material alongside a much more modern set of systems. The day-and-night cycle matters for encounters, your lead Pokémon can follow you in the overworld, and Kanto is part of the intended game rather than an afterthought you discover after the credits.

For exact encounters, use Locations or Encounter Finder. Overworld Pokémon are nice atmosphere. They are not a reliable encounter table, because apparently sprites have been known to lie.

Quality-of-life changes you will notice immediately

Field moves without the HM tax

A Pokémon that can learn a required HM does not need to keep that move in its four-move set to use the corresponding field action. Exploration still has requirements; your movesets just do not have to pay rent for them.

More options around the journey

Heart & Soul includes modern convenience features such as AutoRun, FastSurf, faster wild-battle escaping, quick Poké Ball prompts, more Fly destinations, expanded Bag storage, and a clock in the Start menu. It also retains Johto-flavoured systems including following Pokémon, day and night, Pokégear radio features, Mom's savings, Voltorb Flip, room decoration, and Gen 2-style music through the GB Player.

Trainers, rematches, and Kanto

Trainer teams and the level curve are reworked for a smoother Johto run, with extra difficulty available if you want it. Gym Leader rematches remain, and regular trainer rematches return through Pokégear match calls. Kanto also has its own expanded maps, encounters, rematches, and postgame systems.

Use Trainer Battles for the source-backed records available on PolishedDex. The Walkthrough & Progression Guide is the better place to start when you want the next verified story milestone rather than a spoiler cannon aimed directly at your face.

Modern battle and collection options

A Custom run can choose the Pokémon movepool, Physical/Special split, Fairy type, reusable TMs, Nature Mint availability, selected ability and item behaviour, and recharge-move behaviour.

That means a guide can only be exact for the settings you actually chose. If you change the movepool or battle mechanics, check your configuration before assuming a learnset, type interaction, or TM rule works like the default run.

Heart & Soul also expands the available TM set, includes later-generation abilities and selected items, and supports hidden abilities. That is useful context -- it is not permission to assume every modern Pokémon or item is normally available.

Randomizer, Nuzlocke, and challenge runs

The built-in Randomizer can independently affect starters, wild encounters, trainers, static encounters, legendaries, types, moves, abilities, evolutions, evolution methods, type effectiveness, obtainable items, and chaos mode. In 2.0.4, its generation range is Gen 1–3 or Gen 1–9; Gen 1–3 is the default. The generation-range choice remains adjustable after starting.

Nuzlocke has Off, Easy, Normal, and Hard modes. Easy adds permanent faint removal. Normal adds the tracked-area encounter rule. Hard adds save deletion after a full-party loss. You can also layer on clauses and restrictions such as nicknames, duplicate handling, shiny handling, Pokémon Center limits, shop-cost multipliers, evolution limits, one-type-only runs, base-stat equalization, Mirror Mode, and Mirror Thief.

If you are building a challenge run, do yourself a favour: use Level Caps, Team Builder, and Encounter Finder before committing an encounter or assuming your next boss is forgiving.

A few very non-vanilla details worth knowing

• Apricorns are replaced by berries for Kurt's special Poké Balls.
• Traditional swarms are replaced by a chance to find Hoenn Pokémon on Kanto routes; the Hoenn Sound radio channel can improve that chance.
• Kanto encounter levels are higher than the original game's postgame curve.
• The Pokéathlon Dome is not included.
• The Battle Frontier and Battle Tents use the Modern Emerald implementation.
• Level 50 Frontier rules differ from vanilla Emerald: Pokémon from level 1 through 100 can be set to level 50, while Open Level uses their current level.

What this guide cannot promise

Reference data describes the standard game. Randomized encounters, trainers, moves, abilities, evolutions, and items are deliberately personalised, so the normal Pokédex, trainer, location, and learnset pages cannot magically know what your seed did. Shocking, I know.

For the full setup breakdown, see Features, Settings & Challenge Modes. For current release notes and upstream patch information, use the official Heart & Soul 2.0.4 release.