Silent but Deadly: The Essentials Assassin

Problems with the Essentials Assassin:
It is not made immediately clear (at least, it wasn't to me or the player who chose the assassin, using just the E-tools web character builder and Compendium to create the character, not the book the e-assassin appears in, Heroes of Shadow) that the Essentials Assassin melee-build should have as high a strength as possible if you want to have any chance at successfully using their very cool garrote at-will power.  You can grab an enemy and start choking them out, but they will almost certainly defeat your Fortitude defense with Athletics checks and escape.

Some of my players and I brainstormed a couple of fixes:

Fix 1: A Feat.  This is inspired by the Fighter Feat for grapple-fighters that makes creatures you grab always oppose your Fortitude Defense when trying to escape.

Unshakable Garrote  
Prerequisite: Assassin, Proficiency with Garrote
Benefit:  Creatures you have grabbed with your garrote who are trying to escape always oppose your reflex defense.

This makes you spend a feat for one of your class powers to work the way you want it to, which isn't my favorite thing, but it certainly follows existing design and takes up a less valuable resource (a single feat) than having to max out your strength as your secondary stat.

Fix 2: Skill Challenges.  This idea, combined with Skill Challenges as they are presented in the Rules Compendium, set me on the path of extending the skill challenge system beyond its intended use and creating entire skill-challenge based mini-games.

Quite simply, this fix involves creating a standing skill challenge for garroting enemies.  It would be a complexity 1 skill challenge with a level (and thus DCs) tied to the level of the monster being assassinated.  As complexity 1, it would involve 4 successful moderate DC checks, and not fail until you've failed 3 checks.  Basically, you would always roll a Stealth check (or MAYBE in certain situations, a Bluff check) to approach your target, and the other three checks would be situational:

• Insight to wait until the guard looks distracted 
• Bluff to throw a stone to the other side of the courtyard to distract the guard
• Athletics to tightly wrap the cord around his neck
• Acrobatics to stick with him as he thrashes around
• Perception to watch the guard's patrol patterns in order to strike when other guards aren't looking.
• Endurance to never, ever let go.
• The appropriate monster knowledge check (or a Heal check?) to identify the best way to cut off the air supply of an unusual species.
• Thievery to lock my garrote around his neck so I don't have to maintain the garrote myself.

Basically, this lets the PC and DM co-narrate sneak-and-kill scenarios, allowing every 4 checks to kill a standard monster.  Since it is a Complexity 1 challenge of a level equal to the monster, it is, by the rules, worth the same XP killing that monster in combat should be worth.  And if the PC fails the challenge?  Then he has to fight the monster and he STILL can, if he manages to be hidden, use the combat rules as written.  Of course, in this case, he may have even more monsters come down on him, but that's why he has allies who will, hopefully, rush in to guard his back.

If the PC wants to sneak up on and kill minions, it's even easier: that would take a single check per minion (on the basis that minions counts as a quarter of an enemy, and 4 successful checks win a Complexity 1 encounter).  3 failures between a group of 4 minions alerts any remaining minions in the group, plus whomever else is close enough to come.

Elites and Solos would be WAY harder to do this to, probably impossible.  Complexity 2 challenges seem too easy to take out an elite.  Complexity 4 challenges seem too difficult to narrate reasonably.  Was Jabba an Elite? A Solo?  How good were Leia's skill checks?

I like this because it follows existing 4ed design, but doesn't use up PC resources beyond investment in skills, which PCs likely to do this sort of thing (assassins and rogues) would be doing anyway.  It also opens this sort of activity up to small squadrons taking out facilities on the fly, combining skill checks to get stealth kills.  It might be fun to run a group of stealth-minded PCs through a castle-invasion, and play the whole thing in skill challenge mode until they fail the small skill challenges, then shift to combat.

In conclusion: If I had another PC who wanted to play an Essentials Assassin, I will likely do both of these things in order to make his or her iconic concept, stealth kills, work.