Planning generates sequences of actions called plans. Practical planning for game artificial intelligence (AI) refers to a planning procedure that fits in the AI budget of a game and supports playability so that nonplayer characters (NPCs) execute actions from the plans generated by this planning procedure.
Jeff Orkin developed Goal-Oriented Action Planning (GOAP) [Orkin 04] as the first ever implementation of practical planning for the game [F.E.A.R. 05]. GOAP implements practical planning with (1) actions as C++ classes, (2) plans as paths in a space of states, and (3) search as path planning in a space of states, applying actions backwardly from the goal state to ...