I ran OA yesterday. We started late partly because Ashli's boyfriend Victor wanted to play and needed to make a character and partly because of the general slow moving and procrastination associated with socializing here. D&D is a social activity after all. After Giving them a brief background (they all are retainers of Lord Yabu) I opened the campaign in classic fashion with the Black Riders assaulting the mura of Gobo. Now there were only 4 characters and I may have over role-played Gobo into convincing the samurai stay hidden in his house at first, but I have never seen this fight go down like it did here. Ashli's Akiko nearly one-shotted the leader when she kiai shouted and attacked (the riders were going to take her horse as a "tax payment"); Mona's Midori did one shot the rider that entered Gobo's house to investigate after Akiko charged out of there. Ashli's surprise round and the next round went really well for the party (except John whose character Ryuuro never hit anything)after that though things went south for the party fast. Akiko's surprise round and the party's first round dropped the leader and 3 riders, they would never hit another target and 3 rounds later they were all unconscious and bleeding (except Ryuuro, who at zero I ruled was merely gravely wounded and immobilized).
Now, I have decided that the temple lackeys would take these samurai as prisoners back to the temple for their superiors to decide their fate. This is nearly as bad as dieing for the samurai and not much better for Victor's Bushi Shin. I also decided that it might be better if we had the NPC/back-up PC's that we had talked about earlier. I was a little worried about the party's total lack of magic, particularly healing magic, going into this game; but everyone wanted to play fighter types. I dropped the ball by not having an NPC Shukenja for the party's use.
That said, the party really made some poor tactical decisions (indecision about whether or not to attack the riders to start with, Akiko launching a surprise round on her own when the entire party could have charged out from hiding at once) along the way. However, I think their luck turning bad was the real PC killer here. Also, maybe, me not rebalancing the encounter for fewer PCs. I hate doing that though, it rankles my old school sensibilities to alter an encounter just because they came with 4 PCs instead of the recommended 6 to 8.