If the option determine at begin is enabled, every tile is fully determined when the simulation begins. If the option is not enabled,only those properties are determined, that are needed to calculate the percept for the agent. If the agent is placed on the map, it will start at the specified location and have the specified direction. Else the simulator will chose the starting position. The direction is chosen randomly, although it will not be directly towards a wall or danger that the agent knows about (for example if Lower_X_Bound_Is_Known and the agent starts next to the lower x border, the agent will not face the border). It also avoids facing an enemy that the agent knows about unless the agent can neutralize. If no good starting direction is found, one is chosen randomly among all 4 directions.