Clue (Cluedo) Advanced Strategy
As a kid I would play Clue with my family but none of us were any good at it. I'd use one column on the scoresheet per game and only make notes when it was my turn. I knew there had to be a better way because there is so much information flying around the table when it isn't your turn. You could journal everyone's suggestions and note which player disproved each but it's too much raw data to process. How then to boil that data down into actionable intelligence?
Good players of Clue have adopted a system of recordkeeping that captures the useful information and presents it in manner that's easy to visualize. This video from Jason at StrataGames clearly and concisely explains the key concepts of the system.
If you use this against beginner level opponents then you'll win every time. Once everyone learns this system then you'll only win one sixth of the time on average (note: this article focuses on six handed Clue in which each player is dealt three cards.) That's when you need to make advanced deductions in order to gain the edge over other good players. Read on for my advanced strategy which I call "Play Deep" and soon you'll be winning about half of the time even against five strong opponents.
It can be hard to find five people willing to sit down for a game of Clue, especially if you continually kick their asses. Fortunately there's an excellent video game from Marmalade Game Studio where you can practice against five NPC's on "Hard" mode before progressing to online games against even craftier human types. The video game has a built in scoresheet with multiple columns to encourage the recordkeeping system above. It even does some routine recordkeeping for you.
Each row on the scoresheet represents a card and each column represents a player. Use the cells to deduce which player holds each card. The following table summarizes the notation used in cells on our scoresheets:
! - The player probably does not hold this card.
/ - I know the player doesn't have this card and he knows it too, but other players may not know it yet. Overrides !
X - It's common knowledge that the player does not hold this card. Overrides ! and /
? - Player probably holds this card. Overrides !
O - Player definitely holds this card. Overrides ?
0 through 9 - These numbers come in sets of two or three within a column (the set is called a "notation group") and indicate that the player definitely holds at least one of these cards.
A cell on the scoresheet is said to be a "space" as long as it does not have a / or X
WHEN IT'S ANOTHER PLAYER'S TURN
1. BEFORE PLAY BEGINS
1.0.1. Try not to sit to the left of a strong player
Play always proceeds clockwise both in terms of which player has the next turn and the order in which players are asked to disprove a suggestion. Good players tend to figure out the solution at approximately the same time. If you and the other strong player solve the mystery during the other players' turns, then whichever one of you goes next will win the game.
For these reasons it is a good idea to identify advanced players and try to sit somewhere to their right. This tip mostly applies to the board game. In the video game you may assign difficulty levels "Easy", "Medium" or "Hard" to NPC's on your left and/or right. When playing against human opponents, seating order is randomized and everyone should be considered strong.
1.0.2. Try to play as Mrs. Peacock
In the board game, Mrs. Peacock's starting location is only seven squares away from the Conservatory. All of the other characters are eight squares away from a Room. If everyone rolled seven on their first turn, only Mrs. Peacock would be able to enter a Room to make a suggestion.
In the video game all players start from the center room (i.e. the Cellar). This is fair to all players, allows you to reach the Ballroom with an opening roll of just 4, and gives you the choice of any Room with a roll of 8 or more. I still choose Mrs. Peacock in the video game because she has style!
1.0.3. Prepare scoresheet header with "Me", other players in clockwise order, "Solution"
While play goes around the table clockwise, it goes across your scoresheet from left to right. The left column represents your hand so put the label "Me" at the top. The second column is for the person on your left and so on. Use the rightmost column to represent the solution: the three cards in the secret envelope.
If the scoresheets that came with your board game don't have enough columns then you may download and print this scoresheet that I created in WordPad.
The video game creates the scoresheet for you but does not include columns for "Me" and "Solution". Instead it completely strikes through the rows of all cards in your hand. You may click on a name to circle it and click again to strike it out. The circled names are later presented to you when making your final accusation.
1.0.4. Put 'O' in your column for each card dealt. Fill remainder of rows and column with '/'.
Whenever you know who has a card, place an O in the corresponding row and column. Some people use a check mark but I prefer O because the circle really stands out in a field of diagonal marks like X and /. The video game uses a green check mark which stands out because it's a different color. Your first opportunity to place Os comes before the first roll of the dice because you know which three cards were dealt to you.
Use a / to represent things that you know to be false. Use an X if everybody knows it's false. The video game uses a large ragged X for deductions you made and a neat little x for things it automatically filled in for you. This isn't quite the same semantically but is usually close enough in practice.
At this point, nobody else knows what cards are in your hand. For any row with an O in your column, fill the rest of that row with / because nobody else has those cards. Also fill the rest of your column with / because you know you don't have any other cards.
2.1 Basic Recordkeeping
2.1.1 When someone cannot disprove your suggestion
For each player who cannot disprove your suggestion place an X (or upgrade a / to an X) in their column for the Suspect, Weapon and Room rows. The good news: you know that they don't have any of those three cards. The bad news: everybody else knows too.
2.1.2 When someone can disprove your suggestion
The other player has to show you a Suspect, Weapon or Room card that matches your suggestion. Record an O in the cell for that player and card. Fill the remainder of that row with /s. Those /'s often cross out cells containing numbers. Refer to 3.3.3 below for how to handle this situation.
If the card shown to you is a Room then enter a ! for both the Suspect and Weapon in the other player's column. When given a choice, most players prefer not to show a Room card. So it's a fair bet that they don't have the Suspect or Weapon you suggested.
Record a 0 (that's a zero) in that player's column for the other two cards you suggested but they didn't show you. You are player number 0 and this is how you record your suggestions and which player disproved them. It's okay if there are already 0s in this column. Just add more 0s.
2.2 On your first, second and third suggestions
This is the heart of the Play Deep strategy. The goal is to record an O and cross out one or more numbers on every turn.
Use the following guidelines to choose one Suspect, Weapon and Room to suggest. You can make each of these choices more or less independent of one another (except for 2.2.4 below). It doesn't matter whether all three choices have the same number in the same column or not. Only one of these rows is going to be disproved by a player showing you a card. When that happens you want to make it count for as much as possible.
2.2.1. Prefer rows with numbers preceded by the most spaces.
By "space" I mean a cell on your scoresheet that has neither a / nor an X. The ideal situation is a row with four spaces followed by a number in the rightmost column. The player two seats to your right made a suggestion and the player on your right immediately disproved it. When this happens, try to get to that Room and repeat the suggestion verbatim. The goal is not to go all the way around the table and have the player on your right disprove it to you. Rather, you want one of the other players to disprove it first. Then you get to score an O for the card they show you and put a / through one of the numbers for the player on your right.
2.2.2. Prefer rows with numbers from a notation group of two rather than three.
When a different player shows you a card and you get to erase a number from notation group of three, then you have reduced the notation group to a set of two. If it was already a set of two, however, then you erase one number and upgrade that last remaining number to an O. That's a good way to get two Os on one turn.
2.2.3. Consider choosing an open row rather than one with a number not preceded by spaces.
A row with a number either in the left column or preceded only by a combination of /s and Xs is generally a poor choice for a suggestion. Instead, look for rows without any numbers or that you hold yourself (see "Bluffing" below).
2.2.4. Never suggest a Suspect or Weapon if you already know another player is holding it.
This should go without saying. The goal of your turn is to learn new information, not to confirm something you already know. It's okay to suggest a card that you hold (see "Bluffing") or one that you know to be part of the solution.
There's an exception for Rooms. While it's preferable not to suggest a Room when you know another player is holding it, sometimes the only Room(s) you can reach have already been eliminated. In this case, choose the Room that has the O farthest to the right.
2.2.5. Avoid suggesting the same Suspect, Weapon or Room on multiple turns.
The first time you make a suggestion and it's disproven, the other players will make a number notation on their scorecards. In general they don't know whether the Suspect, Weapon or Room card was shown to you. If you later suggest the same Weapon again then you're telegraphing to the other players that you weren't shown the Weapon card and they may make deductions (see 3.2.2).
This is where the 0 (zero) notation comes in handy. If a cell with a 0 from your earlier suggestion now also contains an X then everybody already knows you weren't shown that card. This isn't great news but it does mean you're free to suggest that card again.
It's not always possible to avoid suggesting the same Room twice. Sometimes you get a low roll of the dice and have one or two choices for a Room you can reach, none of which are optimal. It's better to suggest a Room twice than to make no suggestion at all.
2.2.6. Avoid suggestions that contain exactly two 'X's in the same column.
If the player who disproves your suggestion has two Xs and one space then everyone else will know which card was shown to you. They can all record an O for that row and column. This is your turn and you are learning valuable information but you don't want to share that information with all the other players.
Before making a suggestion, scan the three rows and count how many Xs are in each column. Zero, one and three are all acceptable answers. If you really can't avoid two Xs, try to make it one of the columns toward the right side of your scorecard.
For example, before suggesting Miss Scarlett with the Dagger in the Billiard Room perform this analysis:
2.3 If you have nothing better to do on your first suggestion...
If on your first turn your scoresheet already has numbers in favorable positions then stick with section 2.2 above. Otherwise, this section presents some ideas for what to do when your scoresheet is essentially blank.
2.3.1. Move to a Room far away from the Room(s) you hold and suggest a player on your right.
When you suggest another player as a Suspect that player's token is moved to the Room where you make the suggestion. On his next turn, you don't want a player on your right to suggest a Room that you hold because then you'll have to show him a card.
So pick a Room far away from any Rooms you hold and move him there. Then he will need some luck (either a big roll or another player moving him elsewhere) to reach your Room on his next turn. Beware of secret passages. If you hold the Kitchen, the Study at the opposite corner is actually the closest Room because of the secret passage that connects them. The Library is the furthest Room from the Kitchen.
2.3.2. "Call your own number" and suggest yourself as the Suspect.
When your opponent gets a low roll of the dice and can't reach any Room to make a suggestion, that's good for you. This is most likely to happen on his first turn, in both the board game and the video game. When you suggest a player who has yet to move, you guarantee that he will be able to make a suggestion on his first move. Even if he rolls snake eyes he can still make a suggestion in the Room that you moved him to.
By calling your own name you keep the pressure on the other players to get a decent roll on their first turn.
2.4 On your fourth and later suggestions
At this point in the game it's time to go for the win. Disregard the rules above about not repeating suggestions and columns with two Xs. Instead of rows with numbers, look for rows that are most likely to be a part of the solution.
2.4.1. Avoid rows with question marks.
A ? is almost certainly an O. It probably disqualifies this row from being a part of the solution.
2.4.2. Prefer rows that have the most /'s and X's.
This is simply playing the percentages. A row with four /s is less likely to be disproved than one with only two /s.
2.4.4. Avoid rows with numbers unless there's an 'O' or '?' elsewhere in the notation group.
Think of it this way: If there are two numbers in the notation group then there's greater than a 50% chance the player holds this card (it's greater than 50% because there's a small chance they hold both[i] cards in the notation group). The odds drop to 33+% for notation groups of 3. If there's an O in the notation group then it has already been satisfied and you should erase the numbers (see 3.3.3). It's no more likely the player holds this card than any other. A ? is less certain than an O but the same logic applies.
2.4.5. Prefer rows that have '!'s rather than open spaces.
This is where we put those !s to use. All other things being equal, a row with four Xs and one ! is preferable to one with four Xs and a space.
2.5 Moving your pawn
We'd like to be able to apply the same logic for suggesting a Room as we do for Suspects and Weapons. Unfortunately the rules say we have to roll the dice and move to a Room before we may suggest it. After rolling the dice, first decide which Room to move to. Only then should you consider which Suspect and Weapon to suggest. Your choice may vary depending upon what Room you are in.
2.5.1. If your roll is large enough to reach several Rooms, choose the best one based on the procedures in 2.2, 2.3, and 2.4 above.
On your first three turns try to choose a Room whose row has spaces followed by a number. If it's your first turn choose a Room far away from those you hold. On your fourth and later suggestions try to reach a Room that's likely to be a part of the solution.
2.5.2. All else being equal, prefer corner Rooms.
The great thing about Rooms at the corners of the board is that they are connected by secret passages to the Room at the opposite corner. Secret passages cannot be blocked by another player. Even if you roll snake eyes you will never be stuck in a corner Room.
2.5.3. Avoid the Hall in the video game.
The Hall is the most remote Room in the video game. You need to roll a 5 or better to reach the nearest Rooms. It's easy to get stuck in the Hall and lose a turn. If someone else suggests your name and moves you to the Hall, you have two chances to roll your way out. I suggest you take the first opportunity. If you roll 4 or less the first time, remain in the Hall and suggest it. Hope that you roll 5+ on your next turn or that someone moves you to another Room.
This doesn't apply in the board game. The corner Rooms are connected by secret passages (no roll required) and all other Rooms require only a roll of 4 to reach another Room.
2.5.4. Always move to a Room if you can and make a suggestion, even if you hold that Room or know who does.
If the only Rooms you can reach are ones that you know are held by players, prefer those that you hold. It's less than ideal but at least you have an opportunity to learn more about Suspects and Weapons.
Only as a last resort should you go to a Room known to be held by another player. Choose the one where the O is furthest to the right on your scorecard. When suggesting Suspects and Weapons, choose rows that have spaces and preferably numbers in columns left of the player who holds the Room.
2.6 Bluffing
When you make a suggestion that involves one or more cards that you hold it's called a "bluff". If bluffing were against the rules then you could record three Xs in another player's column every time they made a suggestion. I don't really like the name "bluff" because it implies that the only purpose is to deceive other players. More often bluffing is used to "brute force" a piece of information. If you [i]really want to know if anybody has the Library card, go to the Library and suggest a Suspect and Weapon you hold.
2.6.1. Occasionally bluff, especially when playing against familiar opponents.
If you never bluff and often play against the same opponents, they may catch on and take advantage of you. I only bluff when there's a tactical reason to do so (see below), which happens about every third or fourth game.
2.6.2. If two categories have numbers preceded by many spaces but the third category does not, consider bluffing the latter.
When applying the rules of section 2.2 you may find really good rows for Suspect and Room but no compelling choices for Weapon. It would be a shame to suggest an open row for Weapon only to have it disproved by the player on your left. You would miss out on a golden opportunity for that Suspect and Room.
This is a good time to bluff with a Weapon card that you hold.
2.6.3. If you know part of the solution that is not common knowledge, bluff to maintain the secret.
Suppose you've deduced that the murder weapon is the Lead Pipe. Looking across the Lead Pipe row you see one or more /s among the Xs. You know it is the Lead Pipe but not everybody else does. If you were to suggest the Lead Pipe it may result in the rest of the row being Xed out. Then everybody would know that it's the Lead Pipe.
This is another good time to bluff the Weapon.
2.6.4. If everyone knows part of the solution then do not bluff.
When a row is all Xs then everybody knows it's in the solution. Go ahead and suggest it on every turn until the end of the game. If you bluff now then others will know you're bluffing and deduce what cards are in your hand.
2.7 Making a final accusation
Using the Play Deep strategy you usually have a good opportunity to win the game on your fourth turn, give or take a turn. Sometimes games develop more quickly or slowly. You'll get to know the feeling of when a game is almost over.
2.7.1 When you totally know the solution
Sometimes you will have solved the murder before you even roll the dice. In this case you have several options. The rules of Clue say that you can make your final accusation any time during your turn: before rolling the dice, before moving, before making a suggestion, or after making a suggestion. The video game forces you to roll the dice and move your pawn first and, if you move to a Room, to make a suggestion before any final accusation.
In my opinion, the classy thing to do is not waste anyone's time and make your final accusation as soon as possible. In the board game this is before rolling the dice. In the video game, roll the dice and move out to the common area by the stairs. If being "classy" doesn't appeal to you then you can consider it "showing off" that you solved the murder without even needing your last turn.
The safest thing to do is to confirm your suspicion. Do a dry run of your final accusation by making it a suggestion first. If you were wrong, quickly try to correct your scorecard and improve your final accusation. Sometimes you can't make it to the Room you want to accuse. In this case go to a Room that you hold and, if you can't do that, any Room that doesn't have an O in the left three columns. This will let you partially confirm the Suspect and Weapon.
Another option is to troll one of the other players (see 5.0.3).
2.7.2 When your odds are 1 in 4 or better, make an educated guess.
Sometimes it's good to guess your final accusation. Sure there's a chance that you'll guess wrong and lose but often the alternative is sitting on your hands and watching someone else solve the murder. Nothing ventured, nothing gained.
My rule of thumb is to guess when my chances of being right are at least 1 in 4. If you have solved for Suspect and Weapon and have narrowed it down to four Rooms, guess! If you have solved for Room and have narrowed it down to two Suspects and two Weapons, two times two is four so guess.
Other times there will be, strictly speaking, more than 4 possibilities but some are practically a sure thing such as a row with four Xs and a !, especially when the player with the ! bluffed on his last turn. Use your judgment to calculate your odds versus the odds of somebody else solving if you decide to pass.
2.7.3 Guess rows that are both likely and internally consistent
When it comes to choosing rows for a final accusation Xs and /s are the best, !s are good, ?s and numbers are bad. A number might not be so bad if another member of its notation group has a ?.
You might be tempted to choose a Suspect, Weapon and Room independently using this criteria. It's not that simple. Suppose Miss Scarlett has a number 3 for both Wrench and Ballroom and the rest of her column is Xed out. You definitely do not want to accuse both Wrench and Ballroom because we know she has one of them. On the flip side, you may not want to avoid both Wrench and Ballroom because Scarlett does not have one of them. If the rest of those rows are Xed out then one of them is part of the solution.
3. WHEN IT'S ANOTHER PLAYER'S TURN
3.1 Dice roll
3.1.1. Watch for low rolls of the dice between 2 and 4.
When someone has a low roll they may only be able to reach one Room (or may have to stay in the Room they're in if moved there by another player). In this case, do not record a ! in their Room row (see 3.2.1 below) and do not erase their number elsewhere in their Room row (see 3.2.2 below). They have no choice of Room so we may not infer anything from it.
3.2 The suggestion
3.2.1. When someone makes a suggestion, place an '!' in their column for the Suspect, Weapon and Room.
Even players who bluff regularly tend to suggest cards they don't hold more often than cards they do hold. The ! indicates they are less likely to be holding a card because they suggested it.
3.2.2. Scan the three rows suggested for the number(s) that represent the player making the suggestion. If found then erase that number (but do not put a '/').
If someone suggests the same card twice then they must not have been shown that card the first time. The number in that notation group may be erased because one of the other cards in that notation group must have been shown. It's still possible that the player who originally disproved the suggestion hold both the card shown and the card suggested a second time, so don't eliminate it with a /.
3.3 Recordkeeping with notation groups
3.3.1. When someone cannot disprove the suggestion
Just as in 2.1.1, when someone cannot disprove a suggestion place an 'X' (or upgrade a / to an X) for the Suspect, Weapon and Room. It's useful for you to know when everybody else knows you don't have a card, so be sure to upgrade / to X in your own column (note: this is not possible in the video game).
3.3.2. When someone can disprove a suggestion
Put three numbers in the column (or two numbers, or an O) of the player who disproves a suggestion. The number you use should represent the player who made the suggestion. Most often a notation group will start out with three numbers. If one of the rows already has an X or / in that column then there will be only two numbers in the notation group. If two of the rows have an X then you don't even need a notation group. Just record an O in the only open row.
I usually use the suggester's column number on my scoresheet as the number for the notation group. I'm number 0, the player on my left is 1, and so on. You could also use their first initial if you want to. When a column already contains a notation group with that number you have to get creative. Maybe use their column number plus 5 or their last initial. The video game only allows the numbers 1 through 5. In a pinch, I use the column number of the player who disproved the suggestion and memorize who actually made the suggestion.
3.3.3. Maintenance of notation groups
Whenever a cell gets eliminated with either a / or an X, erase any numbers that were in that cell. Then check the rest of that column. If erasing a number has reduced a notation group to just one remaining number then record an O in that cell.
On the flip side, whenever a cell with a number in it gets confirmed with an O then that notation group is said to be "satisfied". Erase all members of that notation group from the column.
3.3.4. Overlapping notation groups
When two notation groups in the same column overlap on a single row (i.e. there are two numbers in one cell in the column) enter a ? in that cell to indicate it's very likely the player holds that card.
When two notation groups overlap on all three rows, you might be tempted to erase one of the notation groups because it is redundant. Please keep both notation groups side by side in the same column. They indicate two different suggesters were disproven by the same player. If either suggester repeats any part of the suggestion then proceed with 3.2.2 and possibly also 4.0.1.
If a notation group of three and a notation group of two overlap on two rows, see 4.0.1.
If two notation groups of three overlap on two rows then don't do anything extra such as entering ?s. When it's your turn you may suggest one of the solo numbers that does not overlap. Eliminate one of the solo numbers and you can also eliminate the other solo number for free as in 4.0.1.
3.3.5. Non-overlapping notation groups
In six handed Clue each player holds three cards. When a column contains three Os then you know that player's entire hand and can enter a / in every other cell in the column.
Likewise, when a column contains three non-overlapping notation groups (i.e. there are no ?s) then you know that player has one card from each notation group and can enter a / in every cell not containing a number.
Combining both of the above, when the total number of Os and non-overlapping notation groups in a column equals three you may enter a / in every cell except those containing an O or a number.
3.3.6. Pigeonhole principle
Suppose a column contains one O and one ? (i.e. two notation groups that overlap on one row). There are no further deductions that can be made at this time. Now suppose we record another O or non-overlapping notation group in that column. The player can only be holding one other card so you can upgrade the ? to an O, erase the two overlapping notation groups, and / out the rest of the column.
3.3.7. Other recordkeeping
This list could go on an on. Apply some basic logic and you'll figure out more rules as you go along. The publisher of the video game illustrates some rules here. They're all pretty obvious deductions but at least the diagrams are really nice.
3.4 If you can disprove a suggestion
You usually don't have any choice about which card you show to disprove a suggestion: it's the only one your holding. Sometimes another player suggests two (or all three) of your cards. Use the following tips when deciding which card to show.
3.4.1. Prefer the card from a category that everyone should have solved by now.
When one row in the Suspects category is all Xes then everybody should be suggesting that Suspect (or bluffing which is not recommended, see 2.6.4). If someone instead suggests a Suspect you hold then, great, they can see that card.
3.4.2. Prefer cards you've already shown to any player.
Conventional wisdom says "keep track of which cards you've shown to which players in case they ask again". Nonsense. If you've shown a card to a player they're not going to suggest it again (exception: Room plus low dice roll).
However, there is something to be said for showing a card you've previously shown to someone else. Then they're only able to reduce the notation group they already had on you. That's preferable to giving them new information in addition to the notation group, which they're going to resolve eventually anyway.
3.4.3. Prefer to reveal Suspect and Weapon cards over Rooms.
Rooms are the hardest thing to solve by process of elimination. There are nine of them and you have to get good rolls of the dice to reach Rooms that have not already been eliminated. Don't make it easier on your opponents by showing them a Room card if you have a choice. Show them a Suspect or Weapon instead.
3.4.4. Prefer to show cards from the category you hold most.
Suppose you hold one Suspect and two Weapons. Try to keep the Suspect a secret for as long as possible. Show one of the Weapons instead (unless one of the tips above applies).
3.5 If nobody can disprove a suggestion
Once in a while a suggestion will go all the way around the table with nobody disproving it. There's excitement in the air. Did that player just solve the murder or are they bluffing? Here is how to handle it.
3.5.1. Put three numbers in the column of the player who made the suggestion.
In this case I use suggester's column number in their own column. Assume they are bluffing and use this notation group to track it. If your assumption is wrong then they just won the game and it won't matter that your scorecard is wrong.
This notation group is a little different from regular notation groups in that 3.2.2 does not apply. In other words, if this player suggests one of these cards again in the future you should not erase the number from the notation group because they could be bluffing it again.
3.5.2. First option: Repeat the suggestion exactly.
On your next turn the classic strategy is to repeat the suggestion verbatim. If you can't get to the correct Room do not repeat just the Suspect and Weapon. Such a suggestion will have loads of columns with two Xes which is undesirable (see 2.2.6). A verbatim suggestion will be disproved by the player who first made the suggestion. Record the O and erase the notation group. Now you know at least one card they were bluffing.
The problem with this option is they may have been bluffing two or even all three cards. You could spend the rest of the game following up on those leads only to find it has been a wild goose chase.
3.5.3. Second option: Ignore that suggestion and continue the regular strategy.
This is what I usually do: ignore it and suggest three different cards. The player who made the good suggestion has a leg up on the rest of the players but now must solve one (or more) categories that they bluffed. You can get a head start on that job.
Also, the other four players (besides you and the one with the good suggestion) will be falling all over themselves to get in on the action. They often make bad suggestions that reveal information to everybody. You can go about your business and still scoop up the info from their mistakes.
3.6 A failed final accusation
When another player makes a final accusation and fails can reveal much about their own hand and what cards other players are holding.
3.6.1. Place an 'X' in all three rows under the player who made the accusation.
People usually know that a card in their hand is not also in the secret envelope (see 5.0.4 for one exception). Take advantage and X out these three cards in the column of the player making the suggestion.
3.6.2. For all three rows in the accusation, follow the procedure of 3.2.2 above.
Likewise, even beginners are good enough to know not to accuse cards that have been shown to them by other players. Search the three rows for the number of the accuser. Erase any that are found.
3.6.3. If there are any other rows with all 'X's except the accusing player, place an 'O' there.
If everyone knows that the only player who may have the Ballroom is Colonel Mustard (i.e. the rest of the row is all Xs and no /s) and Mustard makes a final accusation about the Dining Room, then he must be holding the Ballroom card. Otherwise he would have accused Ballroom.
4. ADVANCED RECORDKEEPING
4.0.1. The 2-3 rule
When a column has a notation group of three numbers, another notation group with two numbers, and those notation groups completely overlap, then erase the lone number from the notation group with three. This one is easier to visualize with an example:
Here we know that Orchid has Plum, Lead Pipe, or Ballroom. We also know that Orchid has Plum or Ballroom. The second fact is more specific and also satisfies the first notation group. Therefore we can erase the number in the Lead Pipe row. Do not place a / there.
4.0.2. The 2x2 rule
If one column has a notation group of two numbers and another column has a notation group of two numbers on exactly the same rows, then we know that neither row is part of the solution. Place a / in every blank cell in both rows as shown here:
It is important to verify that neither column has a third number in the remaining category (the Rooms in this example). Do not say "it doesn't matter who has which card" and record one O in each row. That can throw off future deductions.
There's also a 3x3 rule where you have identical notation groups of three numbers in three columns. In such a case you could eliminate all three rows. I've never seen this arise in a real game.
4.0.3. Reflection
Whenever you enter a ? check the rest of the row for a number. If that number is part of a notation group of two then enter a ? on the other member of that notation group:
If the original ? later gets erased, remember to also erase the reflected ?.
5. DICK MOVES
5.0.1 If you hold cards for a Suspect, Weapon, and Room, bluff with all three.
This is a somewhat popular dick move, especially early in the game. The theory is that the other players will spend the whole game figuring out your bluffs (see 3.5.2), one card at a time, leaving you free to roam the board and solve the murder yourself. It rarely works out that way, especially if the Suspect you bluff is yourself (you will keep getting dragged back to the same Room). I can't recall seeing anyone win with this unorthodox strategy.
5.0.2 If you can't reach any Room, use your pawn to block a door or narrow corridor.
I actually do this one all the time. If it's my first turn on the video game coming out of the cellar and I can't roll a 4 then I'll just stop at the top of stairs heading toward the Ballroom. Now every player who comes after me will need to roll at least a 5 to reach the Library.
Try to block access to a Room you hold. Even if you can't completely block a doorway, sometimes just placing your token on the shortest path between two Rooms will prevent others from reaching it. Standing anywhere along the narrow hallway between the Library and Billiard Room blocks easy passage between those two Rooms.
If someone's in a corner Room block the only doorway. Now they have to take the secret passage even if it's to a Room they've already been shown.
5.0.3 If you know the solution at the beginning of your turn, make a suggestion consisting of three cards in another player's hand.
I have done this one a few times as well. 
My favorite situation is where I know the solution and every card in the hand of the player on my right as he passes the dice to me. He still hasn't solved this thing. What a loser! If he happens to be holding one Suspect, one Weapon, and one Room then I go to that Room and suggest his whole hand. Then it goes around the table and comes to him to disprove. At this point he could be thinking "I'm being trolled." or "stabguy is more clueless than I am." or "I better show him the Suspect because I don't want him to know my Room." Whatever the case, I turn around and come out with a completely different final accusation for the win. The crowd boos my lack of sportsmanship.
5.0.4 Suicide bluff: Make a final accusation with a card you hold and/or exclude a card you've proven no other players hold.
If you care more about messing with other players than winning the game then you can do this. Basically make a really bad final accusation that will cause other players to spoil their scoresheets. That'll show 'em.
Bump: New video here but it's not showing up on Recent Posts because it has been an unpublished work-in-progress for so long. "Two years in the making..." 
I hope you guys are interested in Clue.
I watched the video when it dropped and didn't even think to come here and look for a post. Haha
“Force has no place where there is need of skill." Herodotus