So, Warlord goes and hits with one of his encounter powers and goes 'Okay, Ranger, you're +1 attack for the encounter'? Every encounter, one of his four encounter powers?
First off, the Warlord has to hit.
Second, the +1 could be for one attack per round.
Nothing says that this is unbalanced, it just has to be designed well. It can work.
+1 is not that huge of a bonus to one PC for an entire encounter.
Wow... that sounds just like the responses people used to have to save or dies. 'So, you rolled an 8 or lower and died. Cry me a river. Boo hoo.'
It might sound like that, but it's hardly an apt comparison.
If you're fighting in a 8 x 8 room with no terrain, it pretty much isn't, to be honest. If you're more able to pick your battlefield, and you do it at ranged to a creature, or a nice burst of creatures, then just keep casually walking away from it... it's extraordinarily powerful.
No, it really isn't. Slow hardly does squat in 4E. There is almost always someone within 4 squares of a foe, at least in the published modules.
There are some unique scenarios where this might be powerful, but it would be rare.
And now they're no longer defending. They're just striking, in a different way. If you want to rebalance all defenders to assume that they'll get to trigger their benefit far, far more often... great, but if not, eh.
So, the current Combat Challenge implementation is flawed because it does damage only???
I consider it fairly sticky, at least in my games. To each their own.
And then goes somewhere else on the battlefield and attacks someone else, since he's going to get attacked no matter what, and that other person has lesser defenses? Eh, doesn't match thematically that well.
Could work if you balanced around it, but that'd screw up the balance of a defender who doesn't have a second defender to force catch 22s.
I'm not sure you understood the concept. He could do this at any time, just like Combat Challenge today. It doesn't require flank.
Combat Challenge: If a foe is within melee attack range of the Fighter and the Fighter can attack, the foe is threatened (i.e. marked) and Combat Challenge works as it does today.
The only difference is that one does not have to keep track of that mark. If the miniature is next to the Fighter miniature, the foe is threatened. No bookkeeping necessary.
It actually makes Combat Challenge a little bit stronger and the Fighter a little bit stickier because every foe around the Fighter is always "marked".
The players just don't need to use the marked terminology and they don't need to do bookkeeping for it. It would be a Fighter Class feature called Combat Challenged. No mark involved. The monsters are "threatened" instead.