Dear Gary,
Do you recall how you had intended the assassination to work for an assassin? Did you intend the rules to say that the assassin always hits (as long as surprise is won), and that normal damage is taken even if the assassination attempt fails? Or did you mean to say the assassin must hit by rolling before he could attempt to assassinate?
Also, when an assassin wins surprise, does he only get 1 segment of surprise to attempt to assassinate, or all the segments he wins (ex. an assassin wins 3 segs. of surprise on a target, would he get only 1 of those 3 to attempt to assassinate, and attack normally for the other 2, get only 1 attack for that sequence of surprises, or something different).
Also, can an assassination be conducted using a missile attack (as long as the assassin wins surprise)?
I have read some who claim that the assassination attempt was meant to be a "plan" handed to the DM that is rolled for (as long as the plan is sound). A single role that shows if the overall plan worked (ex. the plan to hide above in a tree that overhangs a road, as a passing nobel rides by, drop down from above attacking with a dagger to assassinate. This would be considered a single assassination attempt, rather then a role to climb, a role to HIS, a role to see if the nobel happens to be on the wrong side of the road etc.).
Thanks for taking the time to answer such questions. Keep well!

Tx7321