It looks like Crusadar King 2 use bitmap as some kind of mask,and it display it with 3D Terrain.

So what's the general idea to write things like this.Bitmap unregular Bitmap selection and 3D Terrain display.

If convert it to polygon,some pixel may be very ugly and mess up the shape.If don't use polygon.I don't know how to do the 3D detection of BItmap Checking and 3D display with it.

And it also have edge dash line glow effect.How to write those 2D effect and display as 3D effect?

Here is the video how it looks like at about 7:22

Anyone know one thing or two?Or did I post the wrong place.

Off the top of my head (just guessing) I'd say each country is made of triangles and the selection is done with picking.  I think the dash only shows up on the border between two countries and there already seems to be a visual dash without the highlighting.  As far as the outlining goes theres a few ways to implement it,  I'm not sure which one they use, try google for techniques.

edit - I tried a little googlefu and found out that the engine is named the Clausewitz engine (i think 2.0) and its shared with other games.  It also appears to be moddable so if you research modding the graphics that might give you insight on how they accomplish them.