I'd like to qualify this post by saying that I was bored tonight, and really in the mood for D&D. Given that this wasn't a night that the group is available, that means that I decided to do a random playtest. Feeling particularly ambitious, I decided to transcribe everything that happened in this encounter (which I normally don't do). The PCs are all level 6, and the enemy forces are a 9th level encounter for 4 PCs.
In one corner, we have our PCs (some of which you may recognize from the Red Frogs campaign): Lyra Cinderfield (Human Staff Wizard), Berylis Lindelenon (Elf Panther Shaman), Albanon Izariel (Eladrin Assault Swordmage | Charisma Warlock Hybrid, with focus on teleportation), and Unit 27 (Warforged Weaponmaster Fighter). In the other corner, we have the Raven Roost strike force: 3 Raven Roost Outlaw Veterans, 2 Raven Roost Sharpshooters, and 4 Human Thugs (minions). I used the poster map that came with MV2, specifically the one in the woods near the water, with the small cabin (which is where the PCs started out).
This encounter turned out to be the epitome of an encounter-gone-wrong due to cold dice. Albanon missed a total of 10 times out of 16 attacks, for a hit rate of 38%! Doing a rough calculation assuming Eldritch Strike is used, he should have had a 70% hit rate versus the Sharpshooters, 65% vs the Thugs, and 80% vs the Veterans. But the dice just were not on his side, even with attacks granted by Aegis of Assault and Berylis' Claws of the Eagle. Normally I hit the mark pretty well with these playtests, defeating encounters in 4-6 rounds. This one took EIGHT! Healing Spirit was used both times, and Hearth Spirit was also used (both Lyra and 27 took advantage of the 2nd wind as minor despite poor positioning, all made possible by a strategically placed enlarged Winged Horde). Still, nobody ever fell unconscious so the encounter wasn't too challenging, it was just turned into a grind by all of the missing (specifically on the part of the party striker). Surge expenditure (including post-battle recovering back to full health) was as follows: Lyra used 2 surges, Berylis 1, Albanon 2, and 27 3. For much of the encounter Albanon was in danger (bloodied), and Lyra spent several rounds getting between enemies and him (fortunately she has both Shield and Staff of Defense, both of which negated attacks).
Now, I'll fully admit that cold dice weren't the only factor. I'll usually roll randomly before a playtest to determine which PCs have action points available and what, if any, Daily powers can be used. I didn't do that this time, so 1) nobody had action points, and 2) the only dailies I used were Icy Terrain (from Lyra's wand, which I hadn't used in play yet since picking it up with some leftover cash) and Hearth Spirit (because either Lyra or 27 or both would have gone down if I hadn't). Upon further reflection I also didn't focus fire as well as I should have, and tactics were more focused on action denial than anything (Albanon probably could have gotten more consistent CA if I'd tried harder...though to be fair I usually rely on a combination of Stalker's Strike and Claws of the Eagle for that, but they always kept missing).
Unfortunately, this isn't the first time this has happened. At the start of the Red Frogs campaign (before it was even named) the party was TPK'd in a very close fight; one in which my Hunter (a very accurate class) had an absurd missing spree where I rolled 5 or 6 twos and threes. It doesn't seem like anyone else I play with is quite as prone to such severe bouts of bad luck; perhaps I need to stick with a single d20 and develop some superstitious dice rituals (our player who rolls the most crits notably sticks his dice in his mouth a lot...maybe I'll try that?).
So what's a player to do in such circumstances? Well, aside from picking up the standard accuracy boosters (expertise, accurate implements, +3 weapons) one of my strategies is to favor controllers. The more attack rolls you make, the more likely you are to hit something. Definitely enjoying playing Lyra more than that poor Hunter. I'm also fond of implement users that can be flexible about which defense to target. Lyra does exactly this, with an emphasis on Will, which is just perfect. Auto-damage is also nice. Though Lyra hasn't been struck with a major missing streak yet, I think as I level her I may enchant a Wand of Beguiling Strands (my least-used at-will) and trade out that power for Heroic Effort. For the same reason I tend to favor Elf PCs as well. Interestingly, in this playtest encounter I ended up critting with Spirit Hunt in round 1 thanks to Elven Accuracy (talk about a hard-hitting power to crit with!), though lady luck balanced that out when I rolled a 20 for Charm of Misplaced Wrath and a 2 for the attack that it grants. Yeesh.