How To Win Clue! ("Hoe win ikCluedo" is verkrijgbaar door mij te mailen)
Or: Clue for Dummies.

Clue is an adorable game, for age 8 and over. Someone is murdered, and it's up to you and your fellow players to find out who. It's a great game, with a certain luck element and a murder to make things exciting. Your deductive skills and ability to psychoanalyse your opponents will help you find the right cards first. If you want to spoil your game forever, you can spend years finding out how to play it best. But if you're just tired of losing all the time, you can read thisand learn how to improve your playing.
This guide has come from 13 happy years of playing Clue. It's not perfect, but it may give inexperienced players a little help.

This is how I started my article on Cluedo, several years ago. Although the basic outset is still actual and working, I decided to re-vamp my Cluedo page in celebration of this magnificent game setup, and to coincide it with the release of my Cluedo? and FoulPlay pages.
My original page was built in NetScape Composer, which was quite a pleasant tool at the time. Nowadays I prefer to program my entire site in NotePad. My old pages, Bonny1 and TM2, are still more or less intact, but unfortunately something went wrong with it somewhere; many spaces have disappeared. And all the tags are written in caps, which is very annoying. So I'm updating that aspect of my old article.
I also intend to improve the readability. And I intend to focus more on one important aspect of the game I left out. This time, however, I will assume the reader knows the rules to the game.

In this article, I call the game Cluedo. This is the name with which the game was initially marketed in Britain. The name is a pun on Ludo, which is another famous board game.
My style of playing is naturally based on Dutch rules, as I grew up playing the 1992 Dutch edition. (For the true afficionadoes I'd like to note that this was the last edition where the characters were addressed by their English monicres. The next edition saw the translation of the names into the hideous shapes in which they are known today.)
This differs to the US version in three VERY important points:

This changes my tactic greatly. Whenever I play with the Clue PC game or Cluedo?, I end up using the secret passages a lot.

There is one main tactic that is the heart of the win-a-lot strategy. It is the same strategy the computer version uses at Expert level. I see it as the heart of the game, it's what puts it over simple guessing games. The game is not just about ticking off the cards you have in your hand and the cards you are shown. It is about... (drum fill) finding out what cards your opponents get to see.
To illustrate this, I'll sketch out a 6-person game.
Let's say you are Mrs. Scarlett. You have the cards: Scarlett, Dagger, Dining Room.
If Mustard goes to the dining room and suggests Peacock, Dagger, Dining Room, and White shows him a card, you know that the card he showed was Peacock. Simply because you have all the other cards.
If Peacock asks for Peacock, Wrench and Dining Room in her next turn, and Plum shows another card, you know he showed the Wrench card, as you have the Dining Room already and you know that White has Peacock.
If Green asks for Peacock, Wrench and Kitchen in a turn, and he is shown a card by Peacock, you know that Peacock showed the kitchen because the other two cards are accounted for.
You can use this deduction method even for turns where you can't learn anything directly. Just write down who asks what, and who shows.

Another important thing to note is that players might not have a card. Let's say Peacock asks for Scarlet, Revolver, Conservatory. Plum has nothing, so you show Scarlet.
Later on, Green asks for Green, Revolver, Conservatory. Peacock doesn't have anything, but Plum shows a card. You know that Plum didn't have Conservatory or Revolver, so he must have Reverend Green.
So another thing you will have to jot down, is who HASN't got a certain card. That is best done using a Logic Puzzle Grid. To see how you make one of them, check this page: Logic Puzzle on Wikipedia. Or, even easier, use a table that is 6+6+9 rows long, and as wide as the number of players. Remember to write negative marks in the rows where you have a positive mark already, and remember that every person has a fixed number of cards!

So there'll be a lot to write! But it's worth it! With good players it will not be much more than 20 turns anyway. And by deducing, you will actually have to use your head in the game.

If you play with "uninitiated", you're likely to finish way ahead of the others. This is always good for your ego, but your opponents may stress you so that you're forced to share your method. Or perhaps you play with people who know how to play the game anyway. If that is the case, there is another important trick you'll have to learn.
It's called "holding back". Pick a card, preferably a person, that you keep away from other players whenever you can. Especially with three players, such a trick is easy to pull off.
If, for whatever reason, you cannot hold back your card anymore, stay calm and check your notes to see if there's another card you've never shown to your opponents.

And there you have it: pretty much all you ever needed to know about Cluedo tactics. There are still a number of minor interesting tactic aids. It is preferable to be the first to ask the questions, so be Ms Scarlet. Players tend to mimick each other's guesses, but when you are writing down every turn, you don't have to.

If you don't appreciate this type of playing, you may decide to go back to the old only-note-cards, but that will make your game as interesting as Ludo. A nicer way to play it once everybody is overly familiar with deducing, you might like to try the SuperSleuth version: don't write at all. If all players do that, you're bound to get something interesting!