How do I save and load the game?

Short answer

Put the data in a Dictionary, turn it into JSON with JSON.stringify(), and write it to a file under user:// with FileAccess. Loading does the same in reverse.

What to save

The script sits on Main and holds the values worth keeping:

• MainNode2Dthe script goes here

Gather those values into a Dictionary of plain types: numbers, strings, booleans and arrays of them. Save values, not nodes.

main.gd

extends Node2D

var coins := 0
var level := 1

func get_save_data() -> Dictionary:
  return {
    "coins": coins,
    "level": level,
    "position": [position.x, position.y],
  }

Save to a file

Open a file for writing, turn the dictionary into a JSON string, and store it. The file closes on its own when the variable goes out of scope:

GDScript

main.gd

func save_game() -> void:
  var data := get_save_data()
  var file := FileAccess.open("user://save.json", FileAccess.WRITE)
  file.store_string(JSON.stringify(data))

C#

Main.cs

using Godot;
using Godot.Collections;

public partial class Main : Node2D
{
    private int _coins = 0;
    private int _level = 1;

    private Dictionary GetSaveData()
    {
        return new Dictionary
        {
            { "coins", _coins },
            { "level", _level },
            { "position", new Array { Position.X, Position.Y } },
        };
    }

    private void SaveGame()
    {
        using var file = FileAccess.Open("user://save.json", FileAccess.ModeFlags.Write);
        file.StoreString(Json.Stringify(GetSaveData()));
    }
}

user:// is a folder Godot owns for your game, writable on every platform; open it from the editor with Project → Open User Data Folder to see save.json appear. The extension is up to you: .json is a hint to people reading the folder, but .save, .dat or no extension at all works exactly the same, because Godot only cares about the text inside.

Load it back

Check the file exists first, so the very first run doesn’t crash. Then open it for reading, parse the text, and copy the values back:

GDScript

main.gd

func load_game() -> void:
  if not FileAccess.file_exists("user://save.json"):
    return
  var file := FileAccess.open("user://save.json", FileAccess.READ)
  var data = JSON.parse_string(file.get_as_text())
  if data == null:
    return
  coins = int(data["coins"])
  level = int(data["level"])
  position = Vector2(data["position"][0], data["position"][1])

C#

Main.cs

private void LoadGame()
{
    if (!FileAccess.FileExists("user://save.json"))
    {
        return;
    }
    using var file = FileAccess.Open("user://save.json", FileAccess.ModeFlags.Read);
    var data = Json.ParseString(file.GetAsText()).AsGodotDictionary();
    if (data == null)
    {
        return;
    }
    _coins = (int)data["coins"];
    _level = (int)data["level"];
    var pos = data["position"].AsGodotArray();
    Position = new Vector2((float)pos[0], (float)pos[1]);
}

JSON.parse_string() returns null when the text isn’t valid JSON, which is why there is a second check. JSON has no integer type, so every number comes back as a float: data["coins"] is 12.0, not 12, and int() turns it back.

Common mistakes

Writing to res://

res:// is your project folder, and in an exported game it is read-only. FileAccess.open("res://save.json", FileAccess.WRITE) works in the editor and returns null on the player’s machine. Always save under user://.

Putting a node in the dictionary

{"player": $Player} or a Resource reference can’t be turned into JSON; JSON.stringify() writes a useless string in its place. Store the values you need, such as the position and health, not the object that holds them.

Loading before anything was saved

On a fresh install there is no file, so FileAccess.open() returns null and the next line crashes. Check FileAccess.file_exists() first and bail out.

Using loaded numbers as ints

level = data["level"] tries to put a float into an int variable and stops with a type error, and "Level " + str(data["level"]) prints Level 1.0. Convert with int() as soon as you read it.

Related

Saving gamesOfficial guide, including saving several nodes at once.

FileAccessOfficial class reference.