Mental Workout: Casual Challenge! Riddles for Adults
How do you all kill time?
Using your smartphone for the internet or games is the go-to, but even then, there are times when you get bored if you keep doing it, right?
Still, just spacing out and waiting for time to pass doesn’t feel great either.
So how about this: let’s go back to our childhood selves and try some riddles.
I’ve put together questions that should be relatively easy, so give them a shot as a light mental workout.
Some are more like quizzes that require a bit of knowledge, so you might even learn something!
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- [Simple Riddles] A curated selection of fun questions that will excite everyone from kids to adults!
[Brain Teaser] Give it a try! Riddles for adults (21–30)
A cipher quiz using square numbers
Do you know about the Four-Corner Code? The Four-Corner Code assigns digits 0–9 to the four corners of a kanji based on its shape, allowing you to look up characters by form.
Here is a cipher quiz that uses that code.
Each kanji is represented by a four-digit number.
This time there are four four-digit numbers, and it seems to form a four-character idiom.
The order for taking the Four-Corner Code is top-left, top-right, bottom-left, bottom-right.
Let’s match the four-digit numbers and figure out which kanji they represent.
Riddles for advanced users (if you can solve them)
Let’s develop concentration and thinking skills! Here are some ideas for riddles that are challenging even for advanced solvers.
To solve riddles, you need to think carefully and take your time, right? At first glance, the time spent thinking may seem like you’re just playing with riddles, but it’s actually a wonderful opportunity to cultivate various abilities.
This time, let’s try some advanced-level riddles.
For example, you might encounter a question like, “Which country is particular about curry roux?”
Riddle Committee
The creator of the riddle we’re introducing this time is, believe it or not, a sixth-grade girl.
Adults might find it embarrassing if they can’t solve it! They also share the correct answer rate, which adds even more pressure.
Good luck!
A cryptographic quiz derived from nine katakana
A quiz that tests puzzle-solving and flashes of insight, using katakana arranged in a 3×3 grid as hints.
Letters that appear unrelated at first can reveal new meanings by changing their order, placement, or reading.
You’re encouraged to think freely—look for katakana that function as parts of words, try reading vertically or diagonally, and more.
Each solve brings an “aha!” moment, and the mechanism nurtures both imagination and logical thinking.
Those small realizations that become big breakthroughs will spark adult curiosity and make great conversation starters.
Caesar Cipher Quiz
This is a quiz that uses the Caesar cipher, which creates a code by shifting letters by a fixed number.
For example, if you shift “WORLD” forward by 3 letters, it becomes “ZRUOG.” Even if a word looks meaningless at first glance, the key point is that you can reveal the original word by shifting back using the same rule.
To decode it, you need careful observation and patience to determine the correct shift amount, but the sense of accomplishment when you grasp the pattern can be addictive.
It’s perfect as brain training for adults, since you can have fun while honing logical thinking.
Once you get used to it, you can also encrypt your favorite words yourself and exchange them with friends, making it a quiz with a wide range of ways to enjoy.