static void Main(string[] args) { List<Item> recipeItems = new List<Item>() { new Item { Name = "Sword" } , new Item { Name = "Magic Stone" } }; Item outputItem = new Item() { Name ="Super magic sword" }; Inventory inventory = new Inventory() { new Item { Name = "Sword" } , new Item { Name = "Ring" }, new Item { Name = "Magic Stone" } }; CraftingRecipe craftingRecipe = new CraftingRecipe(recipeItems, outputItem); var newlyCraftedItem = craftingRecipe.CraftItem(inventory); if (newlyCraftedItem != null) { Console.WriteLine(newlyCraftedItem.Name); } else { Console.WriteLine("Your item has not been crafted"); } Console.Read(); }