Crowd control done right

I complained some about crowd control in Mass Effect before but today I come before you with nothing but praise.  ME2 really found a fantastic way to deal with crowd control effects that I have not seen before and which seems like a great way to deal with the issue:  Allow crowd control effects only on enemies that have all of their defenses (shield, armor, barriers) destroyed.  The genius of the idea is that it not only works well for bosses but also allows really nice difficulty level scaling too.  Any mooks that the designer wants to be very easy to throw / fear / mind control can be spawned with no defenses allowing the player to horribly abuse them.  Bosses can be started with multiple layers of protection on them though which means that they have to be fought for awhile and have most of their effective health stripped away before they are vulnerable to crowd control effects.  This means that in any given fight crowd control can be used but that simply bringing a barrage of crowd control effects and nothing else will be disastrous whenever you encounter something challenging.  Perfect!

I particularly like this solution because it means that you can dial up the difficulty significantly without completely changing the fight.  Just adding some extra armor or shields onto random enemies not only increases how hard it is to kill them but also means that using CC effects becomes more and more difficult.  On lower difficulties it is fine to lets players horribly maul the enemies by stacking CC but there needs to be some way to mitigate that that isn't just 'MOAR DUDES!' when the difficulty goes up.  There are also the considerations of lore and immersion to keep in mind; having some enemies be inexplicably immune to things can be frustrating and feel very kludgy.  Having a consistent mechanic across the whole game where some enemies have greater protection and cannot be CCed until that protection is gone feels reasonable and the fact that bosses simply have more protections that other people is a nice solution.  Any time you mouse over an enemy you can tell what will work on them and what won't rather than nasty "Sorry, immune to that!" gotcha moments.

In WOW CC was often a problem (Magister's Terrace anyone?) where groups would sit around waiting for a mage because the mage brought the best crowd control in the game.  If a group of four enemies is winnable then a group of three enemies must be extremely easy in comparison so crowd control became very prominent and left those classes or parties without it in a bad situation.  This led Blizzard to give basically every dps class a CC power because otherwise balanced groups and encounters were really hard to design; that is, unless you just made everything immune to CC which has its own problems.  The ME solution is so much better because it lets the designers build challenges that cannot be trivialized by stacking CC without making CC irrelevant.  Given the overall design of WOW fights I can't see how they could implement something similar unfortunately; the design that every monster is pounding on the tank means that CC has to be useful right off the bat or it will be entirely ignored.

Unfortunately I don't have a lot of ideas for how to incorporate this into tabletop games (too much bookkeeping) nor even WOW style fighting games.  The major issue with WOW in this sense is that it has a PvP element.  Setting up the game such that as soon as you get seriously damaged you suddenly lose all control over your character seems like it would be really frustrating and would be quite strange with effective in combat healing.  Not that this solution wouldn't work for MMOs in general but I don't have a particularly good sense of how they run mechanically.  The only one I know inside out is WOW and although CC in WOW is a mess I don't think this (or any other solution I have ever seen) will fix it barring other major system overhauls.