For those who find "Clue" to be too easy and boring, I present
(Cluedo if you're British.)
The board is from any version of "Risk". (Kids may use a Monopoly board, or Candyland.)
One person is the Judge. This person sets the murder combination, sets the Death Traps and Distractions, and hands out the murder tokens privately to each player. Before the game commences, the Judge hands out score sheets which players use to deduce the murder. One score card is notated with the traps and distractions, as well as the murder combination. This score card is handed to the actual murderer, but no one knows who that person is.
The murder tokens are any Monopoly tokens, past or present. The number of tokens equals the number of players. The player without a murder token is defined as the murderer and uses deceit to confuse the other players.
If there are fewer than six players, all players may lie.
The suspects may be any "man" ...chess pieces, mini-figs, patron saint medallions... anything which can fit on the board.
Only the players are suspects.
The maximum number of players is determined by the regions on whichever version of Risk (or Monopoly) is used.
Death Traps and Distractions
Domino pieces are used to create random penalties such as death and distraction. They are placed on the board by the Judge before game play commences.
Death traps are represented by a double domino. Distractions are noted by even-numbered dominoes.
The number of Death Traps is determined by the number of players, limited only by the number of double dominoes available. Half of the remaining spaces are reserved for distractions. The rest of the remaining spaces contain "normal" odd-numbered dominoes.
The murderer knows where they are located, and players can note the number of "safe" areas remaining during game play. (The murderer may throw people off the scent by triggering the bomb.) Given that there are only 42 regions (depending on the Risk board used), this happens quickly.
The player who triggers a Death Trap is redefined as a "ghost", shown either the location card or the murder weapon by the Judge, who in this instance is playing the ghost of the victim. They continue playing the game. Ghosts do not trigger dominoes. Ghosts may tell falsehoods for the remainder of the game. For example, NOT showing a card to disprove a hypothesis, or showing another card to the questioner, making others think that the hypothesis was false when part of it might be true.
There are non-player characters which distract the players. They are defined by even-numbered dominoes. Each reveal loses a turn. (Players refer to this as "In the Pantry with the maid and a bottle of sherry.")
If all players are killed via Death Traps, then the murderer has won, and is given the distinction of being a serial killer. (This is made more difficult as the ghosts learn part of the actual murder combination and might solve the game.) Murderers may also note the number of total players killed before deduction for further distinction.
[Any further suggestions? Let me know in the comments!]