Darkening effect of map edges for isometric game

Hello ! I’m starting to make an isometric game without 3d objects, only the sprites. Very interested in how I can make such effect:alt text

That is the effect of leaving the edges of the territory in the fog for hiding borders of the map. And also little question - if I will make a camera zoom-in, zoom-out effects with small changes in the angle of the camera (like warcraft 3) will this regularly or not for the sprite game?

You could try a shader-based solution, or use volumetric fog. So far, the only VF assets I have found were for use with Unity Pro. A workaround would be to write a simple script that checks if an object is withing the map border zone (and how far away from it), and based on that distance, change it’s material’s main color towards black the farther it is positioned. I don’t know how to do something like this for the ground.
You can also look into the various fog of war tutorials out there, like this one:

Looks like it would work with some modifications.

As for your second question: I don’t understand it. What does “will this regularly or not for the sprite game?” mean?