Modifying Save Data

Learn how to safely modify Pokémon, items, trainer data, and more in save files

Overview

Once you’ve loaded a save file, you can modify various aspects including Pokémon, items, trainer information, Pokédex entries, and game progress. PKHeX.Core provides safe APIs for all modifications.

Always work on a backup copy of save files. Validate checksums after modifications.

Modifying Trainer Information

Basic Trainer Data

var sav = SaveUtil.GetSaveFile("save.sav");

if (sav != null)
{
    // Change trainer name
    sav.OT = "ASH";
    
    // Change Trainer IDs
    sav.TID16 = 12345;
    sav.SID16 = 54321;
    
    // Or set full ID32 (Gen 7+)
    sav.ID32 = 0x12345678;
    
    // Change gender (0 = Male, 1 = Female)
    sav.Gender = 0;
    
    // Change money
    sav.Money = 999999;
    
    // Mark as edited
    Console.WriteLine($"Edited: {sav.State.Edited}");
}

Play Time

// Modify play time
sav.PlayedHours = 255;
sav.PlayedMinutes = 59;
sav.PlayedSeconds = 59;

Console.WriteLine($"Play Time: {sav.PlayTimeString}");

Generation-Specific Properties

// Gen 6+ properties
if (sav is SAV6 sav6)
{
    sav6.Region = 1; // Region code
    sav6.Country = 49; // Country code
    sav6.GameSyncID = "1234567890123456";
}

// Gen 7+ properties
if (sav is SAV7 sav7)
{
    sav7.TrainerTID7 = 123456; // New TID format
}

// Gen 8+ properties
if (sav is SAV8SWSH swsh)
{
    swsh.MyStatus.OT = "TRAINER";
    swsh.MyStatus.Money = 999999;
}

Working with Pokémon

Reading Party Pokémon

var sav = SaveUtil.GetSaveFile("save.sav");

if (sav != null)
{
    Console.WriteLine($"Party Count: {sav.PartyCount}");
    
    for (int i = 0; i < sav.PartyCount; i++)
    {
        var pk = sav.GetPartySlot(i);
        Console.WriteLine($"Slot {i + 1}: {pk.Species} Lv.{pk.CurrentLevel}");
        Console.WriteLine($"  Nickname: {pk.Nickname}");
        Console.WriteLine($"  OT: {pk.OriginalTrainerName}");
        Console.WriteLine($"  Moves: {string.Join(", ", pk.Moves)}");
    }
}

Reading Box Pokémon

// Read a specific box
int boxIndex = 0;
for (int slot = 0; slot < sav.BoxSlotCount; slot++)
{
    var pk = sav.GetBoxSlotAtIndex(boxIndex, slot);
    
    if (pk.Species != 0) // Not empty
    {
        Console.WriteLine($"Box {boxIndex + 1} Slot {slot + 1}: {pk.Species}");
    }
}

Adding Pokémon to Party

// Create a new Pokémon
var pk = sav.BlankPKM;
pk.Species = (ushort)Species.Pikachu;
pk.Form = 0;
pk.CurrentLevel = 50;
pk.Move1 = (ushort)Move.Thunderbolt;
pk.Move2 = (ushort)Move.QuickAttack;
pk.Move3 = (ushort)Move.IronTail;
pk.Move4 = (ushort)Move.ElectroBall;

// Set legal values
pk.HealPP();
pk.Nickname = "PIKACHU";
pk.Ball = (byte)Ball.Poke;
pk.MetLevel = 5;
pk.MetLocation = 1;

// Apply trainer info
pk.OriginalTrainerName = sav.OT;
pk.TID16 = sav.TID16;
pk.SID16 = sav.SID16;
pk.OriginalTrainerGender = sav.Gender;

// Refresh calculated values
pk.RefreshChecksum();
pk.RefreshAbility(pk.AbilityNumber);

// Add to party
if (sav.PartyCount < 6)
{
    sav.SetPartySlot(pk, sav.PartyCount);
    Console.WriteLine("Pokémon added to party!");
}
else
{
    Console.WriteLine("Party is full!");
}

Adding Pokémon to Box

// Add to specific box and slot
int targetBox = 0;
int targetSlot = 0;

sav.SetBoxSlotAtIndex(pk, targetBox, targetSlot);
Console.WriteLine($"Pokémon added to Box {targetBox + 1}, Slot {targetSlot + 1}");

Modifying Existing Pokémon

// Get a Pokémon from party
var pk = sav.GetPartySlot(0);

// Modify properties
pk.CurrentLevel = 100;
pk.Species = (ushort)Species.Charizard;
pk.Form = 0;
pk.Nickname = "CHARIZARD";

// Modify stats
pk.IV_HP = 31;
pk.IV_ATK = 31;
pk.IV_DEF = 31;
pk.IV_SPA = 31;
pk.IV_SPD = 31;
pk.IV_SPE = 31;

pk.EV_HP = 252;
pk.EV_ATK = 252;
pk.EV_SPE = 4;

// Modify moves
pk.Move1 = (ushort)Move.FireBlast;
pk.Move2 = (ushort)Move.AirSlash;
pk.Move3 = (ushort)Move.DragonPulse;
pk.Move4 = (ushort)Move.SolarBeam;
pk.HealPP();

// Set as shiny
pk.SetShiny();

// Update checksum
pk.RefreshChecksum();

// Write back to save
sav.SetPartySlot(pk, 0);
Console.WriteLine("Pokémon modified!");

Cloning Pokémon

// Clone a Pokémon
var original = sav.GetPartySlot(0);
var clone = original.Clone();

// Add clone to box
sav.SetBoxSlotAtIndex(clone, 0, 0);

Modifying Items

Reading Items

var inventory = sav.Inventory;

// Get all items of a specific pouch
var medicines = inventory.Medicine.Items;
foreach (var item in medicines)
{
    if (item.Count > 0)
    {
        Console.WriteLine($"{item.Index}: {item.Count}x");
    }
}

Adding/Modifying Items

// Gen 8 example
if (sav is SAV8SWSH swsh)
{
    var items = swsh.Items;
    
    // Give max regular items
    items.GiveItem(0001, 999); // Master Ball
    items.GiveItem(0002, 999); // Ultra Ball
    items.GiveItem(0017, 999); // Max Potion
    
    Console.WriteLine("Items added!");
}

// Gen 9 example
if (sav is SAV9SV sv)
{
    var items = sv.Items;
    
    items.GiveItem(0001, 999); // Master Ball
    items.GiveItem(1234, 50);  // Any item by ID
}

Working with Item Pouches

var inventory = sav.Inventory;

// Access different pouches
var regularItems = inventory.Items;
var keyItems = inventory.KeyItems;
var tmhm = inventory.TMHMs;
var medicine = inventory.Medicine;
var berries = inventory.Berries;
var balls = inventory.Balls;
var battleItems = inventory.BattleItems;

// Modify a pouch
foreach (var item in regularItems.Items)
{
    if (item.Count > 0)
    {
        item.Count = 999; // Max out all items
    }
}

// Write back
inventory.Items = regularItems;

Modifying Pokédex

Setting Pokédex Entries

// Mark Pokémon as seen/caught
if (sav is SAV8SWSH swsh)
{
    var dex = swsh.Zukan;
    
    // Set species as seen
    dex.SetSeen((ushort)Species.Pikachu, true);
    
    // Set species as caught
    dex.SetCaught((ushort)Species.Pikachu, true);
    
    // Set specific form as caught
    dex.SetCaught((ushort)Species.Pikachu, 0, true);
}

if (sav is SAV9SV sv)
{
    var dex = sv.Zukan;
    
    // Complete Pokédex
    for (ushort species = 1; species <= sv.MaxSpeciesID; species++)
    {
        if (sv.Personal.IsSpeciesInGame(species))
        {
            dex.SetCaught(species, true);
            dex.SetSeen(species, true);
        }
    }
}

Completing Pokédex

public void CompleteDex(SaveFile sav)
{
    if (sav is SAV8SWSH swsh)
    {
        var dex = swsh.Zukan;
        for (ushort i = 1; i <= swsh.MaxSpeciesID; i++)
        {
            if (swsh.Personal.IsSpeciesInGame(i))
            {
                dex.SetCaught(i, true);
            }
        }
        Console.WriteLine("Pokédex completed!");
    }
}

Modifying Box Names and Wallpapers

if (sav is IBoxDetailName boxNames)
{
    // Set box names
    for (int i = 0; i < sav.BoxCount; i++)
    {
        boxNames.SetBoxName(i, $"Box {i + 1}");
    }
}

if (sav is IBoxDetailWallpaper wallpapers)
{
    // Set box wallpapers
    for (int i = 0; i < sav.BoxCount; i++)
    {
        wallpapers.SetBoxWallpaper(i, i % 16); // Cycle through wallpapers
    }
}

Modifying Event Flags

Setting Event Flags

if (sav is IEventFlagProvider flagProvider)
{
    // Set a specific event flag
    flagProvider.SetEventFlag(1234, true);
    
    // Check if flag is set
    bool isSet = flagProvider.GetEventFlag(1234);
    Console.WriteLine($"Flag 1234: {isSet}");
}

// Gen-specific flags
if (sav is SAV8SWSH swsh)
{
    // Set bike unlocked flag (example)
    swsh.SetEventFlag(0x1234, true);
}

Working with Work Values

if (sav is IEventWorkProvider<ushort> workProvider)
{
    // Set work value (variables used by game events)
    workProvider.SetWork(100, 999);
    
    // Get work value
    ushort value = workProvider.GetWork(100);
    Console.WriteLine($"Work 100: {value}");
}

Modifying Game Progress

Badges (Older Generations)

if (sav is SAV4 sav4)
{
    // Set all badges
    for (int i = 0; i < 8; i++)
    {
        sav4.SetFlag(sav4.GetWorkBlock(), i, true);
    }
}

if (sav is SAV6 sav6)
{
    sav6.Badges = 0xFF; // All 8 badges
}

Battle Points

if (sav is SAV6 sav6)
{
    sav6.BP = 9999;
}

if (sav is SAV8SWSH swsh)
{
    swsh.SetValue<uint>(0xYourBPKey, 9999);
}

Working with Multiple Pokémon

Batch Modifications

public void MaximizeAllPartyPokemon(SaveFile sav)
{
    for (int i = 0; i < sav.PartyCount; i++)
    {
        var pk = sav.GetPartySlot(i);
        
        // Max level
        pk.CurrentLevel = 100;
        
        // Max IVs
        pk.IV_HP = pk.IV_ATK = pk.IV_DEF = 31;
        pk.IV_SPA = pk.IV_SPD = pk.IV_SPE = 31;
        
        // Max happiness
        pk.CurrentFriendship = 255;
        
        // Heal
        pk.Heal();
        pk.HealPP();
        
        // Update checksum
        pk.RefreshChecksum();
        
        // Write back
        sav.SetPartySlot(pk, i);
    }
    
    Console.WriteLine("All party Pokémon maximized!");
}

Box Operations

// Clear a box
public void ClearBox(SaveFile sav, int boxIndex)
{
    for (int slot = 0; slot < sav.BoxSlotCount; slot++)
    {
        sav.SetBoxSlotAtIndex(sav.BlankPKM, boxIndex, slot);
    }
}

// Copy box to another
public void CopyBox(SaveFile sav, int sourceBox, int destBox)
{
    for (int slot = 0; slot < sav.BoxSlotCount; slot++)
    {
        var pk = sav.GetBoxSlotAtIndex(sourceBox, slot);
        sav.SetBoxSlotAtIndex(pk.Clone(), destBox, slot);
    }
}

Generation-Specific Features

Gen 8 Records

if (sav is SAV8SWSH swsh)
{
    var records = swsh.Records;
    
    // Set battle records
    records.SetRecord(0, 999); // Example record
    
    Console.WriteLine("Records modified!");
}

Gen 9 Fashion and Appearance

if (sav is SAV9SV sv)
{
    var fashion = sv.PlayerFashion;
    var appearance = sv.PlayerAppearance;
    
    // Unlock all fashion items
    // (specific implementation depends on block structure)
    
    Console.WriteLine("Fashion unlocked!");
}

Data Validation

Validating Modified Pokémon

using PKHeX.Core;

var pk = sav.GetPartySlot(0);

// Validate the Pokémon
var la = new LegalityAnalysis(pk);

if (la.Valid)
{
    Console.WriteLine("Pokémon is legal!");
}
else
{
    Console.WriteLine("Pokémon has legality issues:");
    foreach (var line in la.Report)
    {
        Console.WriteLine($"  - {line}");
    }
}

Sanitizing Data

// Apply sanity checks
public PKM SanitizePokemon(PKM pk, SaveFile sav)
{
    // Ensure level is valid
    if (pk.CurrentLevel > 100)
        pk.CurrentLevel = 100;
    
    // Ensure stats are within bounds
    if (pk.IV_HP > 31) pk.IV_HP = 31;
    if (pk.IV_ATK > 31) pk.IV_ATK = 31;
    // ... etc
    
    // Ensure moves are valid
    var learnset = pk.GetLegalMoves();
    // Validate moves against learnset
    
    pk.RefreshChecksum();
    return pk;
}

Always call pk.RefreshChecksum() after modifying a Pokémon to update its internal checksum.

Best Practices

1. Always work on copies: Never modify the original save file directly
2. Validate data: Check bounds and legal values before setting
3. Update checksums: Call RefreshChecksum() on modified Pokémon
4. Mark as edited: The State.Edited flag tracks changes
5. Test modifications: Load the modified save in-game to verify

public SaveFile SafeModification(string path)
{
    // Load save
    var sav = SaveUtil.GetSaveFile(path);
    if (sav == null) return null;
    
    // Clone for safety
    var modified = sav.Clone();
    
    // Make modifications
    modified.OT = "TEST";
    
    // Validate
    if (modified.ChecksumsValid)
    {
        return modified;
    }
    
    return null;
}

Next Steps

Exporting Saves

Learn how to export and write modified save files

Creating Pokémon

Create new Pokémon with proper attributes