AndEngine will actually adjust the resolution via RatioResolutionPolicy
. Basically you really just want the resolution to be nice and big and for the device you plan to release on.
I made a game for my Galaxy S3 which has a resolution of 1280x720. So if I deploy my game on another phone with lesser resolution AndEngine will adjust it automatically.
Remember one thing, if your game resolution is 1280x720 and your devices resolution is greater (for example 1920x1080) the game will stretch and distort.