That’s what I meant by:
What I’m pondering is making facing and attention a very real and game-impacting facet of the game. If I go that direction, “looking around” may* no longer be a free action (though it’d be VERY cheap), and the direction you are looking when performing actions will impact your ability to perform those actions.
For example, movement penalties for “not looking where you’re going”, melee penalties for looking away from combat, and restricting ranged attacks to enemies in the current view. The default would be no penalties because the view is centered on your character.
*I’m on the fence whether “look around” should have a cost, you make a good argument FOR it having a cost in that otherwise there is no penalty other than convenience for keeping track of any and all enemies within your field of view. That’s definitely bad design because it makes the optimal way of playing really irritating and time-consuming. On the other hand free “look around” has a valuable realism use in that we’re representing a very high-bandwith stream of visual information with a very low-bandwidth representation. “You should be able to glance at a room and see what’s in it”, but just the ASCII or tiles are often insufficient, so roguleikes use “look around” to get information that “should” be available.
An alternative would be to use facing to restrict your field of view even when in “look around” mode, so when in neutral facing you are aware of things within a certain (smaller than it is now) radius , and when facing a certain direction your perception extends further in that direction, but at the cost of developing a blind spot in the opposite direction, and possibly reducing the radius of lateral perception. It would be WAY easier to just add a small cost to looking around instead of messing with rendering, but I’m not sure which is the superior UI.