Could anyone please explain to me the differences between Non-Diegetic, Spatial, Meta and Diegetic User Interfaces? An example for each would be great.
There is an excellent article over at gamasutra which explains it all, but I'll go over what each mean
In terms of game UI, Non-Diegetic is what you would normally associate a typical game UI, an overlay on top of the game. They have the freedom to be completly removed from the games fiction. Non-Diegetic UIs can represent health and ammo or be a hotbar like in World of Warcraft. Non-Diegetic UIs are normally represented two dimensionally.
On the flip side you have Diegetic, which exist in a game world instead of being overlaid onto the game, very much being part of the games fiction. For example a player could press a button to make their character look at their watch to check the time.
Meta UIs are like Non-Diegtic UIs, the difference is that Meta UIs have some way of staying the fiction of the game. A great example is Call of Duty; There is no health bar, but when you are low on health the screen would be overlay with blood to show that you are damaged. Meta UIs are normally represented two dimensionally.
Spatial UIs are again like Non-Diegetic and Meta UIs, but the main difference is that Spatial UIs exist three dimensionally. An example of this is a glowing trail that appears on the floor that the player can follow.