Just read most of the PHB yesterday, and I am confused about a few points.
1) When an adjacent enemy moves away (not shifts), do I get combat advantage AND an attack of opportunity (assuming enemy + me are NOT under any effects/conditions)?
2) same as 1), but when an adjacent enemy uses a ranged/thrown weapon or area affect?
3) For prone: "You get a +2 bonus to all defenses against ranged attacks from nonadjacent enemies." So when I am prone, I get a bonus to defense (vs ranged)?! Just want to make sure
4) Essentially, maybe all of the above can be summed up as "what is the difference between being prone, granting combat advantage, and attacks of opportunity?"