The Passcode module word list holds thirty-five five-letter words, and exactly one of them can be spelled on the bomb's five letter wheels. The Defuser reads all six letters of a wheel, the Expert crosses out every word that does not fit, and the pair repeats wheel by wheel until one word is left to set and submit.
What the Passcode wheels show: five wheels of six letters
The Passcode module has five letter wheels side by side, an arrow above and below each one, and a submit button. Each wheel holds six different letters. The window shows one letter large, with the letters just above and below it printed small and faint. Pressing an arrow turns the wheel by one letter.
So at any moment the Defuser can see three of a wheel's six letters: the large one in the middle and its two neighbours. To see the other three, the Defuser has to turn the wheel. Three presses in either direction bring the hidden half into view, and three more bring the wheel back where it started.
The word showing when the bomb starts is never the answer. The game makes sure of that, so nobody can solve the module by reading the starting row and pressing submit. Every Passcode needs the manual.
Each wheel holds the right letter for its position and five others drawn at random. Those extra letters are what make the list work: they let several words survive the first wheel, but almost never all five.
Why read all six letters of a Passcode wheel?
All six letters matter because the right letter can be any of them. The letter in the window is only one of six possibilities, and the answer is hidden among the other five just as often. Reading only the large letter, or only the three visible ones, throws away information the Expert needs.
The Passcode section of the manual puts it directly: ask the Defuser to read out all six letters on the first wheel. That is the instruction to follow. A Defuser who reads "B, R, T" from the visible three letters and stops has given the Expert half a wheel, and the Expert will cross out words that should have stayed.
A simple way to read a full wheel is to read the three visible letters, press the down arrow three times, and read the three that appear. Or press one arrow six times, reading the large letter each time. Either way, the Defuser should finish by saying "that's six" so the Expert knows the wheel is complete.
Spell every letter clearly. On a call, letters like B, D, P and T blur together. The Defuser can use a word for each letter, or say "B as in bread". The guide to why every Word Grid word must be spelled covers the same problem on a different module, and the same habits work here.
Crossing out Passcode words with the first wheel
With the first wheel's six letters in hand, the Expert goes down the word list and crosses out every word whose first letter is not one of those six. The list is alphabetical, so the work is fast: whole blocks of words that start with the same letter go at once.
Because the list is sorted, the Expert does not need to check each word one at a time. If the six letters are B, K, P, R, W and Z, every word starting with A, C, D and the other missing letters can be skipped as a block. Only the stretches beginning with B, K, P and R are left to read. Letters that start no word on the list, like Z here, simply drop out.
On a printed manual, a pencil line through each word is clearest. On a screen, the Expert can keep a short written list of survivors instead. Either way, the Expert should say how many words are left: "nine left". That number tells the Defuser how much work remains.
A worked Passcode elimination
The letters and the stretch of list below are invented to show the method. To keep it short, the example uses fifteen words, which is less than half of a real list.
Example stretch of the word list:
APPLE, BACON, BASIL, BREAD, CHIVE, CREAM, KEBAB, KNEAD, LEMON, PASTA, PEACH, PESTO, ROAST, SALSA, TOAST
| Step | Example letters | Words still standing |
|---|---|---|
| Start | none | all fifteen |
| After wheel 1 | B, K, P, R, W, Z | BACON, BASIL, BREAD, KEBAB, KNEAD, PASTA, PEACH, PESTO, ROAST |
| After wheel 2 | H, L, M, N, U, X | KNEAD |
After the first wheel, nine words remain: every word starting with B, K, P or R. The second wheel's letters include N but not A, E, O or R, so BACON, BASIL, BREAD, KEBAB, PASTA, PEACH, PESTO and ROAST fall away. KNEAD is the only word left, and the Defuser can stop reading wheels.
How many Passcode wheels does it take to find the word?
The team can stop reading wheels as soon as exactly one word is left. That might happen after two wheels or after four; it depends on the letters dealt. The game guarantees that all five wheels together spell only one listed word, so the elimination always ends with a single survivor.
How quickly the list shrinks depends on the letters the wheels happen to hold. A first wheel with common starting letters leaves many words; a wheel with rare ones may leave three or four. The team has no way to know in advance, which is why the Expert should count the survivors aloud after every wheel.
The Expert should say "stop" the moment one word remains. Reading another wheel after that is not harmful, but it costs time, and on a bomb with other modules waiting, time matters. It can still be worth checking one more wheel when the last elimination felt rushed, as a quick confirmation that the surviving word's next letter really is on the next wheel.
If the list ever reaches zero words, a letter was misheard or a word was crossed out by mistake. Go back one wheel and reread it rather than pushing on.
Setting the Passcode wheels and pressing submit
To set the answer, the Defuser turns each wheel until its large window letter matches the word's letter in that position, left to right. Then the Defuser reads the full row back to the Expert and presses submit. The right word solves the module.
The read-back is the step people skip and regret. After turning five wheels, it is easy to land one letter off on a single wheel. Reading the row aloud, "K, N, E, A, D", lets the Expert compare it with the word on the page before the button goes down.
Turning direction does not matter. Each wheel loops, so pressing up or down will both reach the target eventually. Taking the shorter way just saves a press or two.
In an online room, the Expert cannot see the wheels at all. Experts there see only the main timer, the strike count and how many modules are solved, so the Defuser's read-back is the only way the Expert learns what is actually set. If a needy module wakes halfway through setting the letters, deal with it, then read the whole row again from the left before touching submit. Wheels that were set before the interruption are easy to misremember after it.
The Expert should give the word once and then spell it, rather than spelling only. "KNEAD, K N E A D" lets the Defuser catch a silent letter like the K, which an ear might drop.
The Passcode mistake: submitting before one word is left
Submitting early means setting the wheels to a likely word while two or more words are still standing. The guess has the same chance of being wrong as there are survivors to choose from. A wrong word is a strike, and the wheels stay as they were, so the team has to finish the job anyway.
The pull to guess is strongest when the clock is low and two words remain. It feels like a coin flip worth taking. But reading one more wheel takes a few seconds and settles the question for certain, while a strike also makes the bomb's timer run faster, as the how to play page explains. The guess rarely saves time overall.
A related slip is submitting a word that is spellable but not on the list. The wheels may also happen to spell a real English word that is not one of the thirty-five. Only a word from the manual's list counts, and only the one word that survives every wheel.
Passcode next to the other modules
Passcode is one of the eleven regular modules in Bomb Appétit, a free co-op bomb defusal game that runs in a browser with nothing to install. It rewards a tidy Expert with a pencil.
The Pressure Vent questions and Dial Alignment lights are needy modules that can wake while a Passcode is half done, so it helps to know them before a longer mission. The overview of the 11 modules explained covers the rest.