A game's user interface is the player's entryway into a virtual world - "the plane between reality and your game," says Marcus Andrews in a new Gamasutra feature
. Making sure the player survives that cross-plane transition is crucial.
Andrews compares a UI designer's responsibility with that of a doctor fitting a patient with a prosthetic limb. "[For example, if] a human is robbed of his right arm, a doctor fits a prosthetic arm to take its place. The prosthesis is the interface in this example, and the better the interface, the more right arm functions will be preserved," Andrews explains.
"You could say that this person has crossed his right arm through the plane. Now imagine the prosthesis designer had decided that preserved functionality was not as important as the authenticity of the rubber skin covering the mechanics," he says. "The person with the prosthesis would have a more authentic looking arm, with less preserved functionality. Since UI could be considered a virtual prosthesis, always make preserved functionality your main goal."
Some games go for a UI that encourages a player's immersion in a game. The third-person shooter Dead Space
, for example, doesn't have a traditional HUD and menu system. On-screen notifiers such as health are displayed on the back of the avatar's space suit. Menus are presented as holograms that the avatar can "see" along with the player. All of it is meant to keep the player immersed in that avatar and his world.
Other games like Valve's Team Fortress 2
use a HUD that is up front and straightforward for the most part - health and ammo are always on-screen.
Neither way is really "right" or "wrong," but there are specific factors to keep in mind when designing a UI, Andrews says.
"Players exist in your game in two instances, the 'avatar' and the 'organism.' The avatar is, of course, what is rendered on screen; the organism is what is left of the player after passing through the plane into the game world -- the preservation the game's functionality and its translation into in-game abilities," he says.
"Regardless of your overall UI direction, be it immersion or a HUD your first priority has to be to enable the organism to operate in your game world, otherwise all else will fail. There is simply no viable strategy that allow for neglect of this vital aspect."