Hey I would like to know if it is possible and if there is a tutorial on how to make an object, for example lets say a cube, have an outline on all of its edges in the BGE. I know its possible in rendering but I havn’t been able to find something on making it in the Game Engine. Any help would be nice, and If I have to get into python let me know! Thanks,
TheGamersHaven 
One old trick is to duplicate the mesh in edit mode (no need to separate it), scale it up (or scale up along normals), invert the normals and give those new faces a black shadeless material. Just make sure you do all these steps only to the new duplicated mesh
Thanks it worked! But, I forgot to mention in the original post that I wanted the edges to be outlined in black not just the outline of what you see. What you told me works perfectly and I may do that method but, do you know a way to do it my way?
Here’s the tutorial of what sago said: http://blenderartists.org/forum/showthread.php?t=190153
But I don’t know what you mean in the 2nd post.
I think he wants all edges outlined, so it looks like a wireframe. A method for that would certainly be scripting. First you need to get the mesh of the object (and by that you’ll get all the faces, edges, vertices). Then you could probably create colored lines between these vertices. I didn’t try that out though and maybe there is an easier method…
The artist approach would be to make textures that have all the lines/edges you wish. Combine that with the first method and you can get a nice toony look.
Problem is, if you wish to have this for everything, you need to create those textures for everything…
Well, if you can live with the lines being a bit thinner…
Do what the others said - make a duplicate and scale to normals, but when you scale it, scale it to 1.01. Go to the materials tab and create a new material and check wireframe or wire or whatever. You’ll get an effect kinda like this.
Here’s the blendfile: http://www.pasteall.org/blend/3172
EDIT: Here’s a quick test with a low(ish)-poly human model I had.
Makes for an interesting effect if thats what you’re looking for.