In Discworld, the mouse cursor is an intelligent 'sparkly thing', which leaves a trail of stars behind it as it moves and brings up a label of any item of interest it is currently over. Once a label is displayed, that item can be interacted with by clicking the mouse buttons. Single left click is 'walk to', single right click is 'look at', and double left click is 'action'. This ridiculously simple approach really does work - walking to an object cause Rincewind to stroll over to the object, walk off screen, or whatever. Look at prompts a description of the object in full 'talkie' style, and Use depends on what kind of object it is.
Further ease is lent to the game by the remarkable inventory system used.
Objects are displayed in the inventory window, which can be moved or resized in traditional style by dragging the title bar or a corner respectively. Items can be selected from the inventory and by clicking outside the window, game control is resumed. If you have selected an item, it is now shown under the mouse cursor, and double clicking on an on-screen object now causes Rincewind to try to use the item on the object. In the same way, objects can be combined in the inventory window. I won't spoil the game by giving away too much, but suffice to say the aim of the game is to rid Ankh-Morpork of a rather nasty dragon that has decided to terrorise the city.