diff --git a/build.gradle.kts b/build.gradle.kts
index 003cc8c..f8c864b 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -29,8 +29,8 @@ repositories {
 
 dependencies {
     // The test classes are compiled with these:
-    implementation("com.r35157.libs:random-api:0.0.0")
-    implementation("com.r35157.libs:random-impl-ref:0.0.0")
+    implementation("com.r35157.libs:random-api:0.1-dev")
+    implementation("com.r35157.libs:random-impl-ref:0.1-dev")
     implementation("org.jetbrains:annotations:26.0.1")
 
     // The JUnit platform will not be included in the JAR file but are needed for running the tests:
diff --git a/src/test/java/com/r35157/libs/random/tests/happy/CorrectRandomIntsTests.java b/src/test/java/com/r35157/libs/random/tests/happy/CorrectRandomIntsTests.java
new file mode 100644
index 0000000..2b42cd8
--- /dev/null
+++ b/src/test/java/com/r35157/libs/random/tests/happy/CorrectRandomIntsTests.java
@@ -0,0 +1,81 @@
+package com.r35157.libs.random.tests.happy;
+
+import com.r35157.libs.random.RandomValueGeneratorInt;
+import com.r35157.libs.random.impl.ref.RandomValueGeneratorIntImpl;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@DisplayName("Happy Random Ints Tests")
+public class CorrectRandomIntsTests {
+
+    @DisplayName("Extreme narrow band works - always only one value possible")
+    @Test
+    void testThatEqualMinMaxBoundsWorks() {
+        // Arrange
+        int minBound = 7;
+        int maxBound = 7;
+        int expected = 7;
+        RandomValueGeneratorInt sut = new RandomValueGeneratorIntImpl();
+
+        // Act
+        int actual = sut.getSomeInt(minBound, maxBound);
+
+        // Assert
+        assertEquals(expected, actual);
+    }
+
+    @DisplayName("Produces different values over multiple calls")
+    @Test
+    void producesDifferentValuesOverMultipleCalls() {
+        // Arrange
+        int iterations = 5;
+        RandomValueGeneratorInt sut = new RandomValueGeneratorIntImpl();
+        Set<Integer> seen = new HashSet<>();
+
+        // Act
+        for (int i = 0; i < iterations; i++) {
+            seen.add(sut.getSomeInt());
+        }
+
+        // Arrange
+        assertTrue(seen.size() > 1, "Int generator returned the same value every time");
+    }
+
+    @DisplayName("Will never throw")
+    @Test
+    void noArgsMethodNeverThrows() {
+        // Arrange
+        int iterations = 10_000;
+        RandomValueGeneratorIntImpl sut = new RandomValueGeneratorIntImpl();
+
+        // Act + Assert
+        for (int i = 0; i < iterations; i++) {
+            assertDoesNotThrow(() -> sut.getSomeInt());
+        }
+    }
+
+    @Test
+    void returnsBothPositiveAndNegative() {
+        // Arrange
+        int iterations = 1_000_000;
+        boolean seenPos = false, seenNeg = false;
+        RandomValueGeneratorIntImpl sut = new RandomValueGeneratorIntImpl();
+
+        // Act
+        for (int i = 0; i < iterations; i++) {
+            int v = sut.getSomeInt();
+            if (v > 0) seenPos = true;
+            if (v < 0) seenNeg = true;
+            if (seenPos && seenNeg) break;
+        }
+
+        // Assert
+        assertTrue(seenPos, "Never saw positive number");
+        assertTrue(seenNeg, "Never saw negative number");
+    }
+}
diff --git a/src/test/java/com/r35157/libs/random/tests/sad/IncorrectRandomIntsTests.java b/src/test/java/com/r35157/libs/random/tests/sad/IncorrectRandomIntsTests.java
new file mode 100644
index 0000000..b04c44e
--- /dev/null
+++ b/src/test/java/com/r35157/libs/random/tests/sad/IncorrectRandomIntsTests.java
@@ -0,0 +1,34 @@
+package com.r35157.libs.random.tests.sad;
+
+import com.r35157.libs.random.RandomValueGeneratorInt;
+import com.r35157.libs.random.impl.ref.RandomValueGeneratorIntImpl;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DisplayName("Sad Random Ints Tests")
+public class IncorrectRandomIntsTests {
+
+    @DisplayName("RandomInts.getSomeInts()")
+    @Test
+    void testThatMinBoundIsGreaterThanMaxBoundThrows() {
+        // Arrange
+        int minBound = 10;
+        int maxBound = 5;
+        String expectedErrorMsg = String.format("'minInclusive' (%d) must be less than or equal to 'maxInclusive' (%d)",
+                minBound, maxBound);
+        RandomValueGeneratorInt sut = new RandomValueGeneratorIntImpl();
+
+        // Act
+        IllegalArgumentException thrown = assertThrows(
+                IllegalArgumentException.class,
+                () -> sut.getSomeInt(minBound, maxBound)
+        );
+
+        // Assert
+        String actualErrorMsg = thrown.getMessage();
+        assertEquals(expectedErrorMsg, actualErrorMsg);
+    }
+}