A key/value store to hold data shared by BT tasks. A key/value store to hold data shared by tasks of a behavior tree. Blackboard can serve as a parent scope for another blackboard. In this way, if a value is not found in the active scope, a parent scope Blackboard is asked to return a value. A parent scope Blackboard can have its own parent scope. This structure is called Blackboard scope chain. There is no limit on how many Blackboards can take part in a chain. Blackboard never overwrites parent scope values. A new scope can be created by [BTNewScope] or [BTSubtree] tasks. It is automatically created for any [LimboState] that has a non-empty Blackboard data defined, or for any root [LimboHSM]. Removes variable by name. Returns [Blackboard] data as a [Dictionary]. Returns a [Blackboard] that serves as a parent scope for this instance. Returns variable value. Returns [code]true[/code] if Blackboard contains [code]p_key[/code] variable. Parent scope included. Replaces NodePath variables in the [Blackboard] with references that are retrieved by calling [method Node.get_node] on a [code]p_node[/code] argument. Overrides Blackboard data, discarding anything that was stored at this scope. Use with caution. Sets the parent scope. If a value is not found in the Blackboard's active scope, the parent scope Blackboard will be asked to retrieve it. Sets value of blackboard variable. Returns topmost [Blackboard] in the scope chain.