Fighters have a class feature called Combat Challenge that allows that fighter to mark on a hit or miss, and be able to make a melee basic attack against any adjacent marked enemy who shifts or makes an attack that does not include the fighter as an immediate interrupt.
My question is this: Is this immediate interrupt a special kind of opportunity action or is it really just the fighter's immediate action for the round? If it really is just the immediate action this is a severe limitation, as Combat Superiority and quite a few feats improve Opportunity Attacks (which are a special immediate reaction) but nothing to improve the main feature of the fighter class. Not to mention you can only do this once per round and if you do you forgo any use of any immediate power for that round.
Does anyone have any insight into which this is?
My question is this: Is this immediate interrupt a special kind of opportunity action or is it really just the fighter's immediate action for the round? If it really is just the immediate action this is a severe limitation, as Combat Superiority and quite a few feats improve Opportunity Attacks (which are a special immediate reaction) but nothing to improve the main feature of the fighter class. Not to mention you can only do this once per round and if you do you forgo any use of any immediate power for that round.
Does anyone have any insight into which this is?