Optional Readonlycategoryany item whose category is this
Optional Readonlyidone exact item id, or any of several
Optional Readonlymatchesfull control: an item this returns true for
Readonlyquantityhow many items matching this the recipe needs
What one recipe ingredient consumes.
idis the simple case: one exact item, or any of several.categoryasks for any item of a kind ("any herb plus any runestone"), matching thecategoryan item's definition carries.matchesis the escape hatch when neither fits. Give exactly one of the three.