diff --git a/concepts/when/.meta/config.json b/concepts/when/.meta/config.json
new file mode 100644
index 00000000..3da8d712
--- /dev/null
+++ b/concepts/when/.meta/config.json
@@ -0,0 +1,7 @@
+{
+  "authors": [
+    "kahgoh"
+  ],
+  "contributors": [],
+  "blurb": "When is an alternative to long if / else if / else chains."
+}
diff --git a/concepts/when/about.md b/concepts/when/about.md
new file mode 100644
index 00000000..7fab5927
--- /dev/null
+++ b/concepts/when/about.md
@@ -0,0 +1,147 @@
+# Introduction
+
+Kotlin's `when` is a conditional expression for choosing among several options.
+It is similar to `switch` in Java, and more flexible than a chain of `if` ... `else if` ... `else`.
+
+Like `if`, `when` can also be used as an expression that produces a value.
+
+## Matching a value
+
+Give `when` a value to match in parentheses.
+Each branch compares that value until one matches:
+
+```kotlin
+val animal = "chicken"
+val type = when (animal) {
+    "chicken" -> "bird"
+    "poodle" -> "dog"
+    else -> "unknown"
+}
+// type => "bird"
+```
+
+- Each branch is written as `pattern -> result`.
+- Branches are tried from top to bottom until a match is found.
+  Only the first branch runs.
+- Use `else` for any value not listed above (similar to the final `else` in an `if` chain).
+
+This is similar to [pattern matching][pattern-matching].
+The `pattern` can be a value to match, or use `is` to match by type:
+
+```kotlin
+fun typeText(subject: Any): String {
+    return when(subject) {
+        is Animal -> "Animal"
+        is Fruit -> "Fruit"
+        is String -> "Text"
+        else -> "Unknown"
+    }
+}
+```
+
+or use `in` to check if it is contained in a range, collection, string or anything else with a `contains` method:
+
+```kotlin
+fun describe(number: Int, position: String) {
+    // Range
+    when(number) {
+        in 1..10 -> println("From 1 to 10")
+        in 11..20 -> println("From 11 to 20")
+    }
+
+    // Collection
+    when(number) {
+        in listOf(2, 4, 6) -> println("small even")
+        in listOf(3, 5, 7) -> println("small odd")
+    }
+
+    // String
+    when(position) {
+        in "center middle" -> println("inner")
+        in "left right boundary" -> println("outer")
+    }
+}
+```
+
+~~~exercism/note
+You can also use `in` with other objects by defining the `contains` [operator extension function][kotlin-operator-overloading].
+For example, using it with [Regex][kotlin-regex]:
+
+```kotlin
+operator fun Regex.contains(text: CharSequence): Boolean = this.matches(text)
+
+fun replace(input: String) {
+    return when(input) {
+        in Regex("""ani*""") -> println("animal")
+        in Regex("""fru.*""") -> println("fruit")
+        in Regex("""num.*""") -> println("number")
+        else -> println("unknown")
+    }
+}
+```
+~~~
+
+## Guard conditions
+
+When matching a value, additional conditions can be placed in an `if` after the pattern.
+These conditions are called guard conditions.
+
+```kotlin
+val x = 5
+val y = 10
+val description = when (x) {
+    5 if y % 2 == 0 -> "x is 5, y is even"
+    else -> "other"
+}
+// description => "x is 5, y is even"
+```
+
+Even `else if` can be used.
+
+```kotlin
+val x = 7
+val y = 10
+val description = when (x) {
+    5 if y % 2 == 0 -> "x is 5, y is even"
+    else if y % 2 == 0 -> "y is an even number"
+    else -> "other"
+}
+// description => "y is an even number"
+```
+
+
+## Matching conditions
+
+Alternatively, the value can be omitted and boolean conditions can be placed on each branch:
+
+```kotlin
+val x = 5
+val y = 8
+val description = when {
+    x % 2 != 0 -> "x is odd"
+    y % 2 == 0 -> "y is even"
+    else -> "neither condition matched first"
+}
+// description => "x is odd"
+```
+
+Again, branches are checked from top to bottom and only the first branch whose condition is `true` runs.
+
+## Using `when` as an expression
+
+When `when` is used for its result (assigned to a variable, returned from a function, and so on), every possible case must be covered.
+
+- When matching with a value, add `else` unless every possible value is already handled (for example, all values of a `Boolean` or an `enum`).
+- When matching conditions, an `else` branch is required, because the compiler cannot know that your conditions cover every case.
+
+```kotlin
+fun label(n: Int): String = when (n) {
+    0 -> "zero"
+    1 -> "one"
+    else -> "other"
+}
+```
+
+[kotlin-operator-overloading]: https://kotlinlang.org/docs/operator-overloading.html
+[kotlin-regex]: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin.text/-regex/
+[pattern-matching]: https://en.wikipedia.org/wiki/Pattern_matching
\ No newline at end of file
diff --git a/concepts/when/introduction.md b/concepts/when/introduction.md
new file mode 100644
index 00000000..cd53c1bc
--- /dev/null
+++ b/concepts/when/introduction.md
@@ -0,0 +1,127 @@
+# Introduction
+
+Kotlin's `when` is a conditional expression for choosing among several options.
+It is similar to `switch` in Java, and more flexible than a chain of `if` ... `else if` ... `else`.
+
+Like `if`, `when` can also be used as an expression that produces a value.
+
+## Matching a value
+
+Give `when` a value to match in parentheses.
+Each branch compares that value until one matches:
+
+```kotlin
+val animal = "chicken"
+val type = when (animal) {
+    "chicken" -> "bird"
+    "poodle" -> "dog"
+    else -> "unknown"
+}
+// type => "bird"
+```
+
+- Each branch is written as `pattern -> result`.
+- Branches are tried from top to bottom until a match is found.
+  Only the first branch runs.
+- Use `else` for any value not listed above (similar to the final `else` in an `if` chain).
+
+This is similar to [pattern matching][pattern-matching].
+The `pattern` can be a value to match, or use `is` to match by type:
+
+```kotlin
+fun typeText(subject: Any): String {
+    return when(subject) {
+        is Animal -> "Animal"
+        is Fruit -> "Fruit"
+        is String -> "Text"
+        else -> "Unknown"
+    }
+}
+```
+
+or use `in` to check if it is contained in a range, collection, string or anything else with a `contains` method:
+
+```kotlin
+fun describe(number: Int, position: String) {
+    // Range
+    when(number) {
+        in 1..10 -> println("From 1 to 10")
+        in 11..20 -> println("From 11 to 20")
+    }
+
+    // Collection
+    when(number) {
+        in listOf(2, 4, 6) -> println("small even")
+        in listOf(3, 5, 7) -> println("small odd")
+    }
+
+    // String
+    when(position) {
+        in "center middle" -> println("inner")
+        in "left right boundary" -> println("outer")
+    }
+}
+```
+
+## Guard conditions
+
+When matching a value, additional conditions can be placed in an `if` after the pattern.
+These conditions are called guard conditions.
+
+```kotlin
+val x = 5
+val y = 10
+val description = when (x) {
+    5 if y % 2 == 0 -> "x is 5, y is even"
+    else -> "other"
+}
+// description => "x is 5, y is even"
+```
+
+Even `else if` can be used.
+
+```kotlin
+val x = 7
+val y = 10
+val description = when (x) {
+    5 if y % 2 == 0 -> "x is 5, y is even"
+    else if y % 2 == 0 -> "y is an even number"
+    else -> "other"
+}
+// description => "y is an even number"
+```
+
+
+## Matching conditions
+
+Alternatively, the value can be omitted and boolean conditions can be placed on each branch:
+
+```kotlin
+val x = 5
+val y = 8
+val description = when {
+    x % 2 != 0 -> "x is odd"
+    y % 2 == 0 -> "y is even"
+    else -> "neither condition matched first"
+}
+// description => "x is odd"
+```
+
+Again, branches are checked from top to bottom and only the first branch whose condition is `true` runs.
+
+## Using `when` as an expression
+
+When `when` is used for its result (assigned to a variable, returned from a function, and so on), every possible case must be covered.
+
+- When matching with a value, add `else` unless every possible value is already handled (for example, all values of a `Boolean` or an `enum`).
+- When matching conditions, an `else` branch is required, because the compiler cannot know that your conditions cover every case.
+
+```kotlin
+fun label(n: Int): String = when (n) {
+    0 -> "zero"
+    1 -> "one"
+    else -> "other"
+}
+```
+
+[pattern-matching]: https://en.wikipedia.org/wiki/Pattern_matching
\ No newline at end of file
diff --git a/concepts/when/links.json b/concepts/when/links.json
new file mode 100644
index 00000000..bdd49ba5
--- /dev/null
+++ b/concepts/when/links.json
@@ -0,0 +1,6 @@
+[
+  {
+    "url": "https://kotlinlang.org/docs/control-flow.html#when-expressions-and-statements",
+    "description": "Kotlin when expressions and statements"
+  }
+]
diff --git a/config.json b/config.json
index d2e02ae3..d61eddb1 100644
--- a/config.json
+++ b/config.json
@@ -58,7 +58,7 @@
       },
       {
         "slug": "log-levels",
-        "name": "log-levels",
+        "name": "Log Levels",
         "uuid": "ef54c5e6-7d31-42d1-a300-e405169dbd7f",
         "concepts": [
           "strings"
@@ -68,6 +68,18 @@
         ],
         "status": "wip"
       },
+      {
+        "slug": "guessing-game",
+        "name": "Guessing Game",
+        "uuid": "8ef61603-c6c0-4188-8436-9bd194a2850f",
+        "concepts": [
+          "when"
+        ],
+        "prerequisites": [
+          "conditionals"
+        ],
+        "status": "wip"
+      },
       {
         "slug": "secret-agent",
         "name": "secret-agent",
@@ -1430,26 +1442,26 @@
       "slug": "basics",
       "name": "Basics"
     },
+    {
+      "uuid": "1050abed-4271-4519-a44c-a0ca121c7de2",
+      "slug": "bitwise-operations",
+      "name": "Bitwise Operations"
+    },
     {
       "uuid": "53e0b729-810e-4042-9477-8c8d05a7b302",
       "slug": "booleans",
       "name": "Booleans"
     },
     {
-      "uuid": "157bbe3b-e4f5-41f7-8e0e-e2f57d526617",
-      "slug": "strings",
-      "name": "Strings"
+      "uuid": "660e1acd-3072-4bbc-ae44-bbc204da5eab",
+      "slug": "chars",
+      "name": "Chars"
     },
     {
       "uuid": "168827c0-4867-449a-ad22-611c87314c48",
       "slug": "conditionals",
       "name": "Conditionals"
     },
-    {
-      "uuid": "660e1acd-3072-4bbc-ae44-bbc204da5eab",
-      "slug": "chars",
-      "name": "Chars"
-    },
     {
       "uuid": "c26a1939-deb9-4df7-85c3-f505cdf89e8c",
       "slug": "higher-order-functions",
@@ -1461,9 +1473,14 @@
       "name": "Nullability"
     },
     {
-      "uuid": "1050abed-4271-4519-a44c-a0ca121c7de2",
-      "slug": "bitwise-operations",
-      "name": "Bitwise Operations"
+      "uuid": "157bbe3b-e4f5-41f7-8e0e-e2f57d526617",
+      "slug": "strings",
+      "name": "Strings"
+    },
+    {
+      "uuid": "86b469a5-c21b-4c8b-98c8-942ca210fe36",
+      "slug": "when",
+      "name": "When"
     }
   ],
   "key_features": [
diff --git a/exercises/concept/guessing-game/.docs/hints.md b/exercises/concept/guessing-game/.docs/hints.md
new file mode 100644
index 00000000..bfcd6088
--- /dev/null
+++ b/exercises/concept/guessing-game/.docs/hints.md
@@ -0,0 +1,29 @@
+# Hints
+
+## General
+
+## 1. Reply to a correct guess
+
+- You can match a specific value in a [when][kotlin-when] expression or statement.
+
+## 2. Reply to a close guess
+
+- You can match [multiple values][kotlin-when-multiple-values] on a branch.
+
+## 3. Reply to too low guesses
+
+- The [when][kotlin-when] expression or statement has a way to match anything else that is not matched by the branches.
+
+## 4. Reply to too high guesses
+
+- The [when][kotlin-when] expression or statement has a way to match anything else that is not matched by the branches.
+- You may need to adjust one of the branches from a previous task.
+
+## 5. Reply to a close guess after more than 5 guesses
+
+- There is a [way][kotlin-when-guard-conditions] to add conditions to branches.
+- Remember, the order of the branches is important!
+
+[kotlin-when]: https://kotlinlang.org/docs/control-flow.html#when-expressions-and-statements
+[kotlin-when-multiple-values]: https://kotlinlang.org/docs/control-flow.html#other-ways-to-use-when
+[kotlin-when-guard-conditions]: https://kotlinlang.org/docs/control-flow.html#guard-conditions-in-when-expressions
diff --git a/exercises/concept/guessing-game/.docs/instructions.md b/exercises/concept/guessing-game/.docs/instructions.md
new file mode 100644
index 00000000..03f1d7bd
--- /dev/null
+++ b/exercises/concept/guessing-game/.docs/instructions.md
@@ -0,0 +1,58 @@
+# Instructions
+
+In this exercise, you are playing a number guessing game with a friend. 
+The rules are simple: you secretly choose a number between `1` and `100` and your friend tries to guess what number you've chosen. 
+To help your friend, you respond differently depending on how close the guess was to the number you've chosen (`42`) and how many guesses have been made. 
+These are the rules for the different replies:
+
+- If the guess is `42`: "Correct"
+- If the guess is `41` or `43` and there have been no more than 5 guesses : "So close"
+- If the guess is less than `41`: "Too low"
+- If the guess is greater than `43`: "Too high"
+
+You have four tasks to encode the replies to the guesses.
+
+## 1. Reply to a correct guess
+
+Implement the `reply` function to reply to a correct guess:
+
+```kotlin
+reply(42, 1)
+// => "Correct"
+```
+
+## 2. Reply to a close guess
+
+Modify the `reply` function to reply to close guesses:
+
+```kotlin
+reply(41, 1)
+// => "So close"
+```
+
+## 3. Reply to too low guesses
+
+Modify the `reply` function to reply to too low guesses:
+
+```kotlin
+reply(25, 1)
+// => "Too low"
+```
+
+## 4. Reply to too high guesses
+
+Modify the `reply` function to reply to too high guesses:
+
+```kotlin
+reply(88, 1)
+// => "Too high"
+```
+
+## 5. Reply to a close guess after more than 5 guesses
+
+Modify the `reply` function to reply to close guesses after more than 5 guesses have been made.
+
+```kotlin
+reply(43, 6)
+// => "Try one lower"
+```
\ No newline at end of file
diff --git a/exercises/concept/guessing-game/.docs/introduction.md b/exercises/concept/guessing-game/.docs/introduction.md
new file mode 100644
index 00000000..c17df911
--- /dev/null
+++ b/exercises/concept/guessing-game/.docs/introduction.md
@@ -0,0 +1,129 @@
+# Introduction
+
+## When
+
+Kotlin's `when` is a conditional expression for choosing among several options.
+It is similar to `switch` in Java, and more flexible than a chain of `if` ... `else if` ... `else`.
+
+Like `if`, `when` can also be used as an expression that produces a value.
+
+### Matching a value
+
+Give `when` a value to match in parentheses.
+Each branch compares that value until one matches:
+
+```kotlin
+val animal = "chicken"
+val type = when (animal) {
+    "chicken" -> "bird"
+    "poodle" -> "dog"
+    else -> "unknown"
+}
+// type => "bird"
+```
+
+- Each branch is written as `pattern -> result`.
+- Branches are tried from top to bottom until a match is found.
+  Only the first branch runs.
+- Use `else` for any value not listed above (similar to the final `else` in an `if` chain).
+
+This is similar to [pattern matching][pattern-matching].
+The `pattern` can be a value to match, or use `is` to match by type:
+
+```kotlin
+fun typeText(subject: Any): String {
+    return when(subject) {
+        is Animal -> "Animal"
+        is Fruit -> "Fruit"
+        is String -> "Text"
+        else -> "Unknown"
+    }
+}
+```
+
+or use `in` to check if it is contained in a range, collection, string or anything else with a `contains` method:
+
+```kotlin
+fun describe(number: Int, position: String) {
+    // Range
+    when(number) {
+        in 1..10 -> println("From 1 to 10")
+        in 11..20 -> println("From 11 to 20")
+    }
+
+    // Collection
+    when(number) {
+        in listOf(2, 4, 6) -> println("small even")
+        in listOf(3, 5, 7) -> println("small odd")
+    }
+
+    // String
+    when(position) {
+        in "center middle" -> println("inner")
+        in "left right boundary" -> println("outer")
+    }
+}
+```
+
+### Guard conditions
+
+When matching a value, additional conditions can be placed in an `if` after the pattern.
+These conditions are called guard conditions.
+
+```kotlin
+val x = 5
+val y = 10
+val description = when (x) {
+    5 if y % 2 == 0 -> "x is 5, y is even"
+    else -> "other"
+}
+// description => "x is 5, y is even"
+```
+
+Even `else if` can be used.
+
+```kotlin
+val x = 7
+val y = 10
+val description = when (x) {
+    5 if y % 2 == 0 -> "x is 5, y is even"
+    else if y % 2 == 0 -> "y is an even number"
+    else -> "other"
+}
+// description => "y is an even number"
+```
+
+
+### Matching conditions
+
+Alternatively, the value can be omitted and boolean conditions can be placed on each branch:
+
+```kotlin
+val x = 5
+val y = 8
+val description = when {
+    x % 2 != 0 -> "x is odd"
+    y % 2 == 0 -> "y is even"
+    else -> "neither condition matched first"
+}
+// description => "x is odd"
+```
+
+Again, branches are checked from top to bottom and only the first branch whose condition is `true` runs.
+
+### Using `when` as an expression
+
+When `when` is used for its result (assigned to a variable, returned from a function, and so on), every possible case must be covered.
+
+- When matching with a value, add `else` unless every possible value is already handled (for example, all values of a `Boolean` or an `enum`).
+- When matching conditions, an `else` branch is required, because the compiler cannot know that your conditions cover every case.
+
+```kotlin
+fun label(n: Int): String = when (n) {
+    0 -> "zero"
+    1 -> "one"
+    else -> "other"
+}
+```
+
+[pattern-matching]: https://en.wikipedia.org/wiki/Pattern_matching
diff --git a/exercises/concept/guessing-game/.docs/introduction.md.tpl b/exercises/concept/guessing-game/.docs/introduction.md.tpl
new file mode 100644
index 00000000..6a8a2f34
--- /dev/null
+++ b/exercises/concept/guessing-game/.docs/introduction.md.tpl
@@ -0,0 +1,3 @@
+# Introduction
+
+%{concept:when}
diff --git a/exercises/concept/guessing-game/.meta/config.json b/exercises/concept/guessing-game/.meta/config.json
new file mode 100644
index 00000000..18152fde
--- /dev/null
+++ b/exercises/concept/guessing-game/.meta/config.json
@@ -0,0 +1,20 @@
+{
+  "authors": [
+    "kahgoh"
+  ],
+  "files": {
+    "solution": [
+      "src/main/kotlin/GuessingGame.kt"
+    ],
+    "test": [
+      "src/test/kotlin/GuessingGameTest.kt"
+    ],
+    "exemplar": [
+      ".meta/src/reference/kotlin/GuessingGame.kt"
+    ]
+  },
+  "forked_from": [
+    "fsharp/guessing-game"
+  ],
+  "blurb": "Learn about when expressions by implementing a simple game in which the player needs to guess a secret number"
+}
diff --git a/exercises/concept/guessing-game/.meta/design.md b/exercises/concept/guessing-game/.meta/design.md
new file mode 100644
index 00000000..9d472ecc
--- /dev/null
+++ b/exercises/concept/guessing-game/.meta/design.md
@@ -0,0 +1,15 @@
+# Design
+
+## Learning objectives
+
+- Know how to use `when`.
+- Know how to use guard conditions
+
+## Concepts
+
+- `when`
+
+## Prerequisites
+
+- `strings`: strings will be compared to null and basic methods from strings will be called.
+- `conditionals`: using a conditional statement.
diff --git a/exercises/concept/guessing-game/.meta/src/reference/kotlin/GuessingGame.kt b/exercises/concept/guessing-game/.meta/src/reference/kotlin/GuessingGame.kt
new file mode 100644
index 00000000..50e39300
--- /dev/null
+++ b/exercises/concept/guessing-game/.meta/src/reference/kotlin/GuessingGame.kt
@@ -0,0 +1,10 @@
+fun reply(guess : Int, guessCount : Int) : String {
+    return when(guess) {
+        42 -> "Correct"
+        41 if guessCount > 5 -> "Try one higher"
+        43 if guessCount > 5 -> "Try one lower"
+        41, 43 -> "So close"
+        else if guess < 41 -> "Too low"
+        else -> "Too high"
+    }
+}
\ No newline at end of file
diff --git a/exercises/concept/guessing-game/build.gradle.kts b/exercises/concept/guessing-game/build.gradle.kts
new file mode 100644
index 00000000..534c6ca6
--- /dev/null
+++ b/exercises/concept/guessing-game/build.gradle.kts
@@ -0,0 +1,20 @@
+import org.gradle.api.tasks.testing.logging.TestExceptionFormat
+
+plugins {
+    kotlin("jvm") version "2.4.0"
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation(kotlin("test"))
+}
+
+tasks.withType<Test> {
+    testLogging {
+        exceptionFormat = TestExceptionFormat.FULL
+        events("passed", "failed", "skipped")
+    }
+}
diff --git a/exercises/concept/guessing-game/gradle/wrapper/gradle-wrapper.jar b/exercises/concept/guessing-game/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000..b1b8ef56
Binary files /dev/null and b/exercises/concept/guessing-game/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/exercises/concept/guessing-game/gradle/wrapper/gradle-wrapper.properties b/exercises/concept/guessing-game/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000..83672cc2
--- /dev/null
+++ b/exercises/concept/guessing-game/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.5.1-bin.zip
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/exercises/concept/guessing-game/gradlew b/exercises/concept/guessing-game/gradlew
new file mode 100755
index 00000000..b9bb139f
--- /dev/null
+++ b/exercises/concept/guessing-game/gradlew
@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/3d91ce3b8caaf77ad09f381f43615b715b53f72c/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/exercises/concept/guessing-game/gradlew.bat b/exercises/concept/guessing-game/gradlew.bat
new file mode 100755
index 00000000..aa5f10b0
--- /dev/null
+++ b/exercises/concept/guessing-game/gradlew.bat
@@ -0,0 +1,82 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables, and ensure extensions are enabled
+setlocal EnableExtensions
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute Gradle
+@rem endlocal doesn't take effect until after the line is parsed and variables are expanded
+@rem which allows us to clear the local environment before executing the java command
+endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel
+
+:exitWithErrorLevel
+@rem Use "%COMSPEC%" /c exit to allow operators to work properly in scripts
+"%COMSPEC%" /c exit %ERRORLEVEL%
diff --git a/exercises/concept/guessing-game/settings.gradle.kts b/exercises/concept/guessing-game/settings.gradle.kts
new file mode 100644
index 00000000..e69de29b
diff --git a/exercises/concept/guessing-game/src/main/kotlin/GuessingGame.kt b/exercises/concept/guessing-game/src/main/kotlin/GuessingGame.kt
new file mode 100644
index 00000000..9a75059b
--- /dev/null
+++ b/exercises/concept/guessing-game/src/main/kotlin/GuessingGame.kt
@@ -0,0 +1,3 @@
+fun reply(guess : Int, guessCount : Int) : String {
+    TODO("Please implement the reply function")
+}
\ No newline at end of file
diff --git a/exercises/concept/guessing-game/src/test/kotlin/GuessingGameTest.kt b/exercises/concept/guessing-game/src/test/kotlin/GuessingGameTest.kt
new file mode 100644
index 00000000..09eaf173
--- /dev/null
+++ b/exercises/concept/guessing-game/src/test/kotlin/GuessingGameTest.kt
@@ -0,0 +1,50 @@
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class GuessingGameTest {
+    @Test
+    fun `give hint for 42`() {
+        assertEquals("Correct", reply(42, 1))
+    }
+
+    @Test
+    fun `give hint for 41 on 5th guess`() {
+        assertEquals("So close", reply(41, 5))
+    }
+
+    @Test
+    fun `give hint for 43 on 5th guess`() {
+        assertEquals("So close", reply(43, 5))
+    }
+
+    @Test
+    fun `give hint for 40`() {
+        assertEquals("Too low", reply(40, 1))
+    }
+
+    @Test
+    fun `give hint for 1`() {
+        assertEquals("Too low", reply(1, 1))
+    }
+
+    @Test
+    fun `give hint for 44`() {
+        assertEquals("Too high", reply(44, 1))
+    }
+
+    @Test
+    fun `give hint for 100`() {
+        assertEquals("Too high", reply(100, 1))
+    }
+
+    @Test
+    fun `give hint for 41 on 6th guess`() {
+        assertEquals("Try one higher", reply(41, 6))
+    }
+
+    @Test
+    fun `give hint for 43 on 6th guess`() {
+        assertEquals("Try one lower", reply(43, 6))
+    }
+
+}
\ No newline at end of file
diff --git a/exercises/settings.gradle.kts b/exercises/settings.gradle.kts
index 9994cb25..b34a8e6b 100644
--- a/exercises/settings.gradle.kts
+++ b/exercises/settings.gradle.kts
@@ -1,5 +1,6 @@
 include(
     "concept:annalyns-infiltration",
+    "concept:guessing-game",
     "concept:log-levels",
     "concept:lucians-luscious-lasagna",
     "concept:secret-agent",