We didn't describe anything like a service in our Expected Behaviour, and that's fine – it means that we don't need anything like a service for our Behavior, per-se. However, each Behavior Tree has to update the relevant values somehow. One way to do this is by using a service.
The kinds of services that update specific values are often specific (in the implementation) and less likely reusable, but sometimes they are needed to run the Behavior Tree. Moreover, since we already looked at a practical example on how to create a Task and a Decorator, this is the occasion to learn a bit more about Services.
We need to think about the variables contained in the Blackboard, and which one needs to be updated.
The first variable that we need to assign is the Player. In fact, we need to have a reference to the Player Pawn so...