While we love the theme and movement system of Kill Doctor Lucky, we found its murder resolution system to be unsatisfying after a few games. Mostly, it's a game of bluffing that you don't have Failure cards in order to conserve yours as long as possible, not one of setting up that perfect murder attempt...
So, in the Cheapass tradition, here is a variant that doesn't require any extra components, except for a standard six-sided die.
All rules of Kill Doctor Lucky are used except for resolving murder attempts.
Once a murder attempt has been announced, every player (except the Murderer), starting with the player to the left of the Murderer and proceeding clockwise, may play one F1 or F2 card from his or her hand in order to move a player's pawn one space (with a F1 card) or two spaces (with a F2 card).
A player may move any pawn except the Murderer, Dr. Lucky or a pawn that has already been moved by another player during this murder attempt (tip over each pawn as it is moved to indicate this).
Once all F1 or F2 movement is done, resolve the murder attempt by rolling a die. If the number rolled is less than or equal to the Weapon number of the murder attempt, modified by -2 for each 'witness' to the Murder created by F1 or F2 movement, then the murder tentatively succeeds. Otherwise, it tentatively fails.
(Note that players are not required to move pawns with F1 or F2 cards so as to make them witnesses. They are free to take advantage of a murder attempt's chaos to move pawns to other locations.)
After the die is rolled, all players -- except the Murderer -- may play one or more F3 cards to each add '1' to the number rolled. The Murderer may play one or more F3 cards to each subtract '1' from the number rolled.
Once all players had played all F3 cards they wish to play (players may respond to each other's plays until all players are done playing F3 cards), the murder attempt is completely resolved:
If the modified die roll is less than or equal to the adjusted Weapon number, the attempt succeeds and the game is over. Otherwise, discard all Failure cards used and continue play.
Example:
A murder with a 4 Weapon is attempted. During failure movement, one witness is created for -2. A '2' is rolled, so the murder tentatively succeeds. One player plays an F3 card to make the result a "3" (failure); the Murderer plays an F3 card to make the result a "2" again; and another player plays a third F3 card to make it a "3". The Murderer has no more F3 cards, so this attempt fails and the game continues.
This variant places a premium on your skill in setting up murders. The right weapon in the right place can produce a "7" or "8" attempt. Even if the players can get one or two witnesses in place (reducing these attempts to, say, a "5" or a "4"), the Murderer still has a reasonable chance of winning with a good die roll, despite the other players possibly holding a couple of the four F3 cards.
Even a poke in the eye, if everyone else is more than two rooms away, has a chance of winning the game... Enjoy!