EDIT: Thanks for all your answers and comments. After thinking about it i would rephrase the core of the question to: "How to determine and limit the minimum resolution/ratio my game is able to run on". Because imo either the game becomes unplayable on the smallest screen/ratio (lack of detail) or supporting even the smallest screen/ratio degrades the experience for all the others significantly. Besides we do not even know what the smallest resolution is or can restrict it in any way other than disabling ldpi... which still doesn't tell us about the smallest mdpi. After all i'm not thinking about how to create a good result but about how to create a perfect result ;). Guess it's not possible (yet?).
Note: This is purely about phones not tablets Also this question is not that relevant for applications as it is for games which don't use the Android layout system.
I always found the definitions of which resolutions to expect somewhat vague. I am aware of the list in the docs.
Now my first question is if this list is complete or in other words are manufacturer allowed to use other reolutions or aspect ratios. My current approach is to view this list in terms of aspect ratios which looks something like that (Not sure if it's exact but you get the idea):
So if i want to cover a range of devices i figure out what my smallest and my biggest aspect ratios are and design the layout for the smallest while making it automatically grow to the biggest. For example if i want to support all densities i design the screens for 4:3 and make it grow to 16:9. In case i remove ldpi support i would design for 3:2. Of course this assumes there will never be an mdpi device with an aspect ratio of 4:3 which brings us back to my first question.
My preferred solution would be to indicate on the Android Market which aspect ratios my application can handle but that doesn't seem possible so far.
Does anyone have a better approach? (Keeping in mind that it's for games on phones only)
I can't directly answer your question, but i'd like to tell you my approach. I try not to use to use any numbers at all. Instead I try using paddings, margins and relative layouts so that my views look correctly on any phone. It also helps me to avoid creating view for different orientations.