Slot Rules

Slot Rules allow you to restrict what items can be placed into specific inventory slots. This is essential for equipment systems (e.g., ensuring a helmet can only go in the head slot).

SlotDefinition (Resource)

Every slot in an Inventory has a corresponding SlotDefinition. - display_name: Name of the slot (e.g., "Head", "Weapon"). - icon_placeholder: Texture shown when the slot is empty. - rules: An Array[SlotRule] that must all pass for an item to be accepted. - allow_drag_out / allow_right_click: UI interaction restrictions.

Base Class: SlotRule (Resource)

All rules extend SlotRule.

# Returns true if the item is allowed in this slot.
func can_accept_item(item: ItemDefinition, slot_index: int, inventory: Inventory) -> bool

# Returns a human-readable string explaining why the item was rejected.
func get_rejection_reason(item: ItemDefinition, slot_index: int) -> String

Built-in Rules

EquipmentTypeRule

Locks a slot to a specific integer equipment_type. - Property: equipment_type (int). - Usage: Set the rule's equipment_type to 1. Set your Helmet item's equipment_type to 1.

ItemTagRule

Requires items to have specific string tags. - Properties: required_tags (Array[String]), match_any (bool). - Usage: If match_any is true, the item needs at least one of the tags. If false, it must have all of them.

MaxOneRule

Prevents items from stacking in a specific slot (e.g., equipment slots). - Usage: Add this to equipment slots so players can't stack 64 Iron Swords in a single weapon slot.

Rule Implementation Details

EquipmentTypeRule.can_accept_item() uses item.get("equipment_type") rather than item.equipment_type due to a potential missing meta check in the code. This works for direct property access but may behave differently if the item lacks the property.