inventory-system

Inventory, Equipment, and Crafting System

Patterns for building a complete item management pipeline: define items as ScriptableObjects, store them in a slot-based inventory, equip gear, craft new items, and bind everything to UI.

Item Definition (ScriptableObject)

Every item in the game is defined as a ScriptableObject asset. This keeps data out of code, lets designers create items in the editor, and makes save/load straightforward (reference by ID, not by full object).

using UnityEngine;

public enum ItemType
{
    Consumable,
    Equipment,
    Material,
    QuestItem,
    Currency
}

public enum EquipmentSlotType
{
    None,
    Head,
    Body,
    Weapon,
    Shield,
    Accessory
}

[CreateAssetMenu(fileName = "New Item", menuName = "Inventory/Item Definition")]
public class ItemDefinition : ScriptableObject
{
    [Header("Identity")]
    public string itemId;           // Unique ID for save/load: "sword_iron_01"
    public string displayName;
    [TextArea(2, 4)]
    public string description;
    public Sprite icon;

    [Header("Stacking")]
    public bool isStackable = true;
    public int maxStackSize = 99;

    [Header("Type")]
    public ItemType itemType;
    public EquipmentSlotType equipSlot = EquipmentSlotType.None;

    [Header("Stats (for equipment)")]
    public int attackBonus;
    public int defenseBonus;
    public int healthBonus;
    public int speedBonus;

    [Header("Usage (for consumables)")]
    public int healAmount;
    public int manaRestoreAmount;

    [Header("Economy")]
    public int buyPrice;
    public int sellPrice;
}

Naming convention for itemId: Use snake_case with category prefix. Examples: sword_iron_01, potion_health_small, mat_wood_plank. This makes save files human-readable and debugging easier.

Item Registry

Maintain a central registry so you can look up an ItemDefinition by its itemId. This is essential for save/load (you save the ID string, then reconstruct the reference on load).