Generation 8 Save Files

Save file implementations for Nintendo Switch Pokemon games.

SAV8SWSH

Save file for Pokemon Sword and Shield.

Class Definition

public sealed class SAV8SWSH : SaveFile, ISaveBlock8SWSH, ITrainerStatRecord, 
    ISaveFileRevision, ISCBlockArray, IBoxDetailName, IBoxDetailWallpaper

Source: PKHeX.Core/Saves/SAV8SWSH.cs

Save Revisions

Sword and Shield has 3 save revisions based on DLC:

public int SaveRevision { get; } // 0, 1, or 2
public string SaveRevisionString { get; } // "-Base", "-IoA", "-CT"

// Revision 0: Base game (Vanilla)
// Revision 1: DLC 1 - Isle of Armor
// Revision 2: DLC 2 - Crown Tundra

Storage Specifications

Property	Base	IoA	CT
Box Count	32	32	32
Max Species	400	500	664
Max Move	796	826	850
Max Item	1278	1489	1589
Max Ability	258	260	267

SCBlock System

Gen 8 introduced the SCBlock (Save Block) architecture:

public IReadOnlyList<SCBlock> AllBlocks { get; }
public SCBlockAccessor Accessor { get; }
public T GetValue<T>(uint key) where T : struct
public void SetValue<T>(uint key, T value) where T : struct

Blocks are accessed by 32-bit hash keys:

public Box8 BoxInfo => Blocks.BoxInfo;
public Party8 PartyInfo => Blocks.PartyInfo;
public MyItem8 Items => Blocks.Items;
// ... etc

Block Accessors

public SaveBlockAccessor8SWSH Blocks { get; }
public MyStatus8 MyStatus { get; }
public Coordinates8 Coordinates { get; }
public Misc8 Misc { get; }
public Zukan8 Zukan { get; }
public BoxLayout8 BoxLayout { get; }
public PlayTime7b Played { get; }
public Fused8 Fused { get; }
public Daycare8 Daycare { get; }
public Record8 Records { get; }
public TrainerCard8 TrainerCard { get; }
public FashionUnlock8 Fashion { get; }
public RaidSpawnList8 RaidGalar { get; }
public RaidSpawnList8 RaidArmor { get; }
public RaidSpawnList8 RaidCrown { get; }
public TitleScreen8 TitleScreen { get; }
public TeamIndexes8 TeamIndexes { get; }

Key Properties

public override uint ID32 { get; set; }
public override ushort TID16 { get; set; }
public override ushort SID16 { get; set; }
public override GameVersion Version { get; set; }
public override byte Gender { get; set; }
public override int Language { get; set; }
public override string OT { get; set; }
public override uint Money { get; set; }
public int Badges { get; set; }

Box Management

public override int BoxCount { get; } // 32
public override int CurrentBox { get; set; }
public override int BoxesUnlocked { get; set; }
public string GetBoxName(int box)
public void SetBoxName(int box, ReadOnlySpan<char> value)
public int GetBoxWallpaper(int box)
public void SetBoxWallpaper(int box, int value)

public override byte[] BoxFlags { get; set; }
// Secret box unlock status

Battle Teams

public TeamIndexes8 TeamIndexes { get; }
public override StorageSlotSource GetBoxSlotFlags(int index)

Max Raid Battles

public RaidSpawnList8 RaidGalar { get; }  // Base game dens
public RaidSpawnList8 RaidArmor { get; }  // Isle of Armor dens
public RaidSpawnList8 RaidCrown { get; }  // Crown Tundra dens

Diglett Hunt (IoA)

public void UnlockAllDiglett()
{
    // Unlocks all 150 Alolan Diglett in Isle of Armor
    // Sets flags and counters for all zones
}

Form Arguments

protected override void SetPKM(PKM pk, bool isParty = false)
{
    PK8 pk8 = (PK8)pk;
    pk8.UpdateHandler(this);
    
    if (FormArgumentUtil.IsFormArgumentTypeDatePair(pk8.Species, pk8.Form))
    {
        pk8.FormArgumentElapsed = pk8.FormArgumentMaximum = 0;
        pk8.FormArgumentRemain = (byte)GetFormArgument(pk8);
    }
    pk8.RefreshChecksum();
}

private static uint GetFormArgument(PKM pk)
{
    if (pk.Form == 0) return 0;
    return pk.Species switch
    {
        (int)Species.Furfrou => 5u,
        (int)Species.Hoopa => 3u,
        _ => 0u,
    };
}

Record Tracking

public int RecordCount { get; } // ~100 records
public int GetRecord(int recordID)
public void SetRecord(int recordID, int value)
public int GetRecordMax(int recordID)
public int GetRecordOffset(int recordID)

No Traditional Checksums

public override bool ChecksumsValid => true;
public override string ChecksumInfo => string.Empty;
protected override void SetChecksums() { } // No checksums!

SAV8BS

Save file for Pokemon Brilliant Diamond and Shining Pearl.

Class Definition

public sealed class SAV8BS : SaveFile, ISaveFileRevision, ITrainerStatRecord, 
    IEventWorkArray<int>, IBoxDetailName, IBoxDetailWallpaper, IDaycareStorage, 
    IDaycareEggState, IDaycareRandomState<ulong>

Source: PKHeX.Core/Saves/SAV8BS.cs

Save Revisions

public int SaveRevision { get; } // Game version
public string SaveRevisionString { get; } // e.g., "V1_3"

// v1.0: Launch version
// v1.1: First update (RecordAdd, MysteryRecords blocks)
// v1.2: Second update (additional Hall of Fame tracking)
// v1.3: Final update

Storage Specifications

Property	Value
Box Count	40
Box Slot Count	30
Party Size	6
Daycare Slots	2

Block Structure

BDSP uses a fixed-offset block system:

public FlagWork8b FlagWork { get; }           // 0x00004
public MyItem8b Items { get; }                // 0x0563C
public UndergroundItemList8b Underground { get; } // 0x111BC
public SaveItemShortcut8b SelectBoundItems { get; } // 0x14090
public Party8b PartyInfo { get; }             // 0x14098
public BoxLayout8b BoxLayout { get; }         // 0x148AA
// Boxes start at 0x14EF4

// Player Data Block (0x79B74+)
public ConfigSave8b Config { get; }
public MyStatus8b MyStatus { get; }
public PlayTime8b Played { get; }
public Contest8b Contest { get; }
public Zukan8b Zukan { get; }
public BattleTrainerStatus8b BattleTrainer { get; }
public MenuSelect8b MenuSelection { get; }
public FieldObjectSave8b FieldObjects { get; }
public Record8b Records { get; }
public EncounterSave8b Encounter { get; }
public PlayerData8b Player { get; }
public SealBallDecoData8b SealDeco { get; }
public SealList8b SealList { get; }
public RandomGroup8b Random { get; }
public FieldGimmickSave8b FieldGimmick { get; }
public BerryTreeGrowSave8b BerryTrees { get; }
public PoffinSaveData8b Poffins { get; }
public BattleTowerWork8b BattleTower { get; }
public SystemData8b System { get; }
public Poketch8b Poketch { get; }
public Daycare8b Daycare { get; }
public UgSaveData8b UgSaveData { get; } // Underground
public UnionSaveData8b UnionSave { get; }
public ContestPhotoLanguage8b ContestPhotoLanguage { get; }
public ZukanSpinda8b ZukanExtra { get; }
public UgCountRecord8b UgCount { get; }

Version-Specific Blocks

public bool HasFirstSaveFileExpansion { get; } // v1.1+
public bool HasSecondSaveFileExpansion { get; } // v1.2+

// v1.1 additions
public RecordAddData8b RecordAdd { get; }
public MysteryBlock8b MysteryRecords { get; }

Key Properties

public override uint ID32 { get; set; }
public override GameVersion Version { get; set; }
public override byte Gender { get; set; }
public override int Language { get; set; }
public override string OT { get; set; }
public override uint Money { get; set; }
public string Rival { get; set; }

Position Data

public short ZoneID { get; set; } // Current map
public float TimeScale { get; set; } // Default: 1440.0f

Daycare System

public int DaycareSlotCount { get; } // 2
public bool IsDaycareOccupied(int slot)
public bool IsEggAvailable { get; set; }
public Memory<byte> GetDaycareSlot(int index)
public ulong Seed { get; set; } // LCRNG seed

Event Work

public int EventWorkCount { get; } // FlagWork8b.COUNT_WORK
public int GetWork(int index)
public void SetWork(int index, int value = 0)

Battle Teams

public override StorageSlotSource GetBoxSlotFlags(int index)
{
    int team = TeamSlots.IndexOf(index);
    if (team < 0) return StorageSlotSource.None;
    
    team /= 6;
    var result = (StorageSlotSource)((int)StorageSlotSource.BattleTeam1 << team);
    if (BoxLayout.GetIsTeamLocked(team))
        result |= StorageSlotSource.Locked;
    return result;
}

Checksums

BDSP uses MD5 hashing:

private const int HashLength = 16; // MD5.HashSizeInBytes
private const int HashOffset = SaveUtil.SIZE_G8BDSP_0 - HashLength;

protected override void SetChecksums()
{
    var current = CurrentHash;
    current.Clear();
    RuntimeCryptographyProvider.Md5.HashData(Data, current);
}

public override bool ChecksumsValid
{
    get
    {
        var current = CurrentHash;
        Span<byte> exist = stackalloc byte[HashLength];
        current.CopyTo(exist);
        SetChecksums();
        var result = current.SequenceEqual(exist);
        if (!result)
            exist.CopyTo(current); // restore
        return result;
    }
}

SAV8LA

Save file for Pokemon Legends: Arceus.

Class Definition

public sealed class SAV8LA : SaveFile, ISaveBlock8LA, ISCBlockArray, 
    ISaveFileRevision, IBoxDetailName, IBoxDetailWallpaper

Source: PKHeX.Core/Saves/SAV8LA.cs

Save Revisions

public int SaveRevision { get; } // 0 or 1
public string SaveRevisionString { get; } // "-Base" or "-DB"

// Revision 0: Base game (Vanilla)
// Revision 1: Daybreak update

Storage Specifications

Property	Value
Box Count	32
Box Slot Count	30
Party Size	6
Total Capacity	960 Pokemon

SCBlock System

Similar to SWSH, uses SCBlock architecture:

public IReadOnlyList<SCBlock> AllBlocks { get; }
public SCBlockAccessor Accessor { get; }
public T GetValue<T>(uint key) where T : struct
public void SetValue<T>(uint key, T value) where T : struct

Block Accessors

public SaveBlockAccessor8LA Blocks { get; }
public Box8 BoxInfo { get; }
public Party8a PartyInfo { get; }
public MyStatus8a MyStatus { get; }
public PokedexSave8a PokedexSave { get; }
public BoxLayout8a BoxLayout { get; }
public MyItem8a Items { get; }
public Epoch1970Value AdventureStart { get; }
public Coordinates8a Coordinates { get; }
public Epoch1900DateTimeValue LastSaved { get; }
public PlayTime8b Played { get; }
public AreaSpawnerSet8a AreaSpawners { get; }

Key Properties

public override uint ID32 { get; set; }
public override GameVersion Version { get; set; }
public override byte Gender { get; set; }
public override int Language { get; set; }
public override string OT { get; set; }
public override uint Money { get; set; } // Max: 9,999,999
public override uint SecondsToStart { get; set; }

Pokedex System

Legends Arceus uses a research-based Pokedex:

public PokedexSave8a PokedexSave { get; }

protected override void SetDex(PKM pk)
{
    // Updates research progress, not just seen/caught
    PokedexSave.OnPokeGet_TradeWithoutEvolution(pk);
}

public override bool GetCaught(ushort species)
{
    if (species > Personal.MaxSpeciesID)
        return false;
    
    var formCount = Personal[species].FormCount;
    for (byte form = 0; form < formCount; form++)
    {
        if (PokedexSave.HasAnyPokeObtainFlags(species, form))
            return true;
    }
    return false;
}

public override bool GetSeen(ushort species) 
    => PokedexSave.HasPokeEverBeenUpdated(species);

Area Spawners

Manages wild Pokemon spawns:

public AreaSpawnerSet8a AreaSpawners { get; }
// Controls which Pokemon spawn in each area

Box Management

public override int CurrentBox { get; set; }
public override int BoxesUnlocked { get; set; }
public string GetBoxName(int box)
public void SetBoxName(int box, ReadOnlySpan<char> value)
public int GetBoxWallpaper(int box)
public void SetBoxWallpaper(int box, int value)

public override byte[] BoxFlags { get; set; } // 3 secret boxes

No Traditional Checksums

public override bool ChecksumsValid => true;
public override string ChecksumInfo => string.Empty;
protected override void SetChecksums() { }

Technical Notes

SwishCrypto

Gen 8 Switch games use SwishCrypto for encryption:

// SWSH and LA
public SAV8SWSH(Memory<byte> data) : this(SwishCrypto.Decrypt(data.Span)) { }
protected override Memory<byte> GetFinalData() => SwishCrypto.Encrypt(AllBlocks);

// BDSP uses raw data (no encryption at save level)

SCBlock Architecture

SCBlocks use 32-bit FNV-1a hashes as keys:

var flag = "FSYS_UI_WAZA_MACHINE_RELEASE_001";
var hash = (uint)FnvHash.HashFnv1a_64(flag);
var block = Accessor.GetBlock(hash);

PKM Formats

SWSH: PK8 (stored and party both 0x148 bytes)
BDSP: PB8 (stored and party both 0x158 bytes)
PLA: PA8 (stored 0x168 bytes, party 0x168 bytes)

String Encoding

All Gen 8 games use StringConverter8:

public override string GetString(ReadOnlySpan<byte> data)
    => StringConverter8.GetString(data);

Party Format in Boxes

Gen 8 stores Pokemon in party format even in boxes:

public override int SIZE_BOXSLOT => PokeCrypto.SIZE_8PARTY;
public override byte[] GetDataForBox(PKM pk) => pk.EncryptedPartyData;

Core Classes

PKM Formats

Save File Types

Editing

Legality

Utilities

​Generation 8 Save Files

​SAV8SWSH

​Class Definition

​Save Revisions

​Storage Specifications

​SCBlock System

​Block Accessors

​Key Properties

​Box Management

​Battle Teams

​Max Raid Battles

​Diglett Hunt (IoA)

​Form Arguments

​Record Tracking

​No Traditional Checksums

​SAV8BS

​Class Definition

​Save Revisions

​Storage Specifications

​Block Structure

​Version-Specific Blocks

​Key Properties

​Position Data

​Daycare System

​Event Work

​Battle Teams

​Checksums

​SAV8LA

​Class Definition

​Save Revisions

​Storage Specifications

​SCBlock System

​Block Accessors

​Key Properties

​Pokedex System

​Area Spawners

​Box Management

​No Traditional Checksums

​Technical Notes

​SwishCrypto

​SCBlock Architecture

​PKM Formats

​String Encoding

​Party Format in Boxes

Build docs developers (and LLMs) love

Generation 8 Save Files

SAV8SWSH

Class Definition

Save Revisions

Storage Specifications

SCBlock System

Block Accessors

Key Properties

Box Management

Battle Teams

Max Raid Battles

Diglett Hunt (IoA)

Form Arguments

Record Tracking

No Traditional Checksums

SAV8BS

Class Definition

Save Revisions

Storage Specifications

Block Structure

Version-Specific Blocks

Key Properties

Position Data

Daycare System

Event Work

Battle Teams

Checksums

SAV8LA

Class Definition

Save Revisions

Storage Specifications

SCBlock System

Block Accessors

Key Properties

Pokedex System

Area Spawners

Box Management

No Traditional Checksums

Technical Notes

SwishCrypto

SCBlock Architecture

PKM Formats

String Encoding

Party Format in Boxes