Chapter 10. User Interfaces
A game typically has two main components to its user interface: a menu system and an in-game heads-up display (HUD). The menu system defines how the player gets in and out of the game—including changing modes, pausing the game, selecting options, and so on. Some games (especially RPGs) may also have menus to manage an inventory or upgrade skills.
The HUD includes any elements that give additional information to the player as he or she is actually playing the game. This can include a radar, ammo count, compass, and an aiming reticule. Although not all games will have a HUD (and some might have the option to disable the HUD), the vast majority have at least a basic one.
A well-implemented menu system should ...