Common Puzzles:
Morse Code
Morse code is one of many forms of substitution puzzles where you substitute a symbols for a letter, number, or another symbol. Watch for dots and dashes. They usually use other items to make the dots and dashes. Balls and bats can be dots and dashes. Many different items can be used as dots and dashes: erasers and pencils, bouncy balls and pickup sticks, wheels and pogo sticks, etc. I've even see watches and their wristbands used as dots and dashes. It's possible your cipher will also connect other symbols to dots and dashes or to letters. That will sometimes look like this:
Pigpen Cipher
When I find a pigpen cipher in a room, I start searching for V shapes (in all directions), squares, and squared off U shapes (in all directions). If you see a backward L, that's an A. If you see an square, that's an E. If you see a square with a dot in it, that's an N. If you see a V, that's an S. If you see an upside-down V with a dot in it, that's a Z. Dots in incomplete squares and in V shapes are almost always a clue to search for a pigpen cipher.
Caesar's Encryption Disc
A Caesar cipher is another common form of substitution puzzle. It requires players to substitute a letter, number, or some other symbol on a wheel. The inner or outer wheel will spin so you'll need to find a clue that will tell you how far to spin the wheel. Arrows, colors, or an initial solution (such as A=D as show in this image) will indicate how far you should spin the wheel. These wheels can have letters, numbers, colors, or images on them, but the solutions are found the same way. Sometimes, you will need to turn the wheel to find every symbol.
Text
When you find text, whether is a magazine, letter, book, or any other form of writing, you will often (usually) need to look at the text, not for its obvious message, but for a hidden message. Designers hide messages in letters by putting words along the left or right side of a paragraph. When you read those words in order, they will form a sentence. Are there bold words in a text? Those words probably form a sentence. The same can be done with words in all caps, in various colors, in italics, underlined, etc. Are letters in some of those words replaced by numbers? Read the word that has a one in it, then the word that has a two in it, and continue on until a sentence is formed. If you find a sheet with holes in it, the holes my reveal words in a text that form a sentence or some numbers for a combination.
Counting Items
If there are a bunch of similar items in a room (like balls, sticks, rocks, etc.), compile all those items to see if there are similarities between some of the items. If you have a pile of rocks and notices that there are four different colors of rocks, count all the same colors to find for numbers. If there are four green rocks, three red rocks, six yellow rocks, and one black rock. There's probably a four-digit number combination lock somewhere in the room. There's also probably something in the room that has those same four colors on it to reveal the order to put those numbers in the lock. These puzzles can go the opposite way too. If there are three black rocks, one blue rock, two red rocks, and four green rocks, the clue is attempting to tell you the order of the colors. The order is blue (1), red (2), black (3), green (4). You will need that color order for something else in the room.
Clues in Books
It's important to flip through books to see if anything is stuck in the pages of the book, but don't read books unless something points you to the book (magazine, newspaper, etc.). Too many people spend time reading then later find a clue that tells them exactly what small portion of the book to read. You'll usually be pointed to a few letters or words in the book. If you see the letters T P L W followed by words and numbers, it might be pointing you to the Title of the book, the Page in the book, the Line on the page, and the Word (almost always counted left to right) on the line.
Soundtracks
Ambient noises often give clues. Listen for whispers that give clues, beeps or tones in the form of morse code, numbers in sentences (won = 1, too = 2, for = 4, high five = 5, ate = 8, etc.), or even the direction the sound is coming from.
Lighting
Don't forget to test light switches. Don't assume that just because there are lights on in a room that you should test the switch. If there is a light pointing at a specific object or a portion of the room, the light might lead you to a clue, but it might distract you from the real clue. If something is suspiciously dark, explore it or find a way to light it.
Mazes
Another overused puzzles is the maze. There will probably be a metal ball in a maze that can't be moved because it has a plexiglass sheet on it. Find a magnet and move the ball through the maze. Sometimes you'll have to spin or tilt the maze to move the ball. The most clever use of a maze I've seen used a vacuum to suck an object out of a maze.
Hooks
If you find a pole or rope with a hook or magnet on it, stick that hook in everything it will fit in. Often you will have to assemble the hook or magnet to a pole or rope, but hooks and magnets are often used to retrieve objects from seemingly unreachable places.
Black Lights
This is perhaps the most overused escape room puzzle mechanic. If you find a black light, point it at everything until you find what glowing information it reveals.
Clocks
When you get into a room, look to see if there are any clocks in the room. If there are, check to see if they are set to the correct time and if they are moving. If they are not moving and are set to the wrong time, the clock is giving your a clue. A clock set to 11:00 is probably telling you that the solution to a four digit lock in the room is 1100.
Radios
If you find a working radio, there is likely a low power radio transmitter somewhere in the room. You will hear a clue come from the radio when you turn the radio to the correct channel or when you move the disguised transmitter close to the radio.
Maps
Most map puzzles require you to use the grid to find locations on a map or to connect locations to a letter/number combination. Usually there will be letters along the top of the map and numbers on the left side. Find the location that the clue is pointing to and follow the grid to find the letter (column) and number (row) that the location is in. In this example, the fire station is in the 4H square. The movie theater is in the 4B square. If the clue pointed you first to the fire station then to the movie theater, you now have the code for a four digit lock (4H4B). This same thing can be accomplished on a checker/chess/scrabble board, on an ice tray, on a sudoku, or on any other grid. You probably won't need to know geography very well to solve the puzzle.
