When it comes to HUDs in games there are 3 types of HUDs first is a permanent HUD that is the information constantly displayed on screen in a game it would be the timer or speedometer. after that comes the pull up HUD this is information a player can bring up usually at anytime but isn’t constantly visible like when you go on the option menu on a action game and it shows you the full map or icon information. the third is actioned HUD this is information the comes up after a player has done something to trigger the information to appear such as blood to show your health on a shooter game when you’ve been shot this only appears after the player has been shot and other wise will not be visible.
When creating a HUD you have to consider the UI and UX. The UI stands for user interface which makes up part of the HUD, this is A user interface is the method by which the user and the computer exchange information and instructions. It refers to the methods (keyboard control, mouse control) and interfaces (inventory screen, map screen) through which a user interacts with the game. while UX stands for user experience this refers to how enjoyable the interactions that make up the user interface are.
The main difference between to the two design wise is that while User Experience is a combination of tasks focused on optimising a product for effective and enjoyable use. The user interface design is its strong point, it focuses on the look and feel, interactivity of a product.