Game Representation We represent a game by the tuple H, A, T, R, Ψ , where H is the set of all possible game states, A = {(a, o)} is the set of all commands (action-object pairs), T (h | h, a, o) is the stochastic transition function between states and R(h, a, o) is the reward function.
the game state H is hidden from the player, who only receives a varying textual description, produced by a stochastic function Ψ : H → S. the underlying state h in the game engine keeps track of attributes such as the player's location, her health points, time of day, etc.