diff --git a/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/BehaviorAssertion.java b/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/BehaviorAssertion.java
new file mode 100644
index 0000000..9bd6984
--- /dev/null
+++ b/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/BehaviorAssertion.java
@@ -0,0 +1,44 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+import com.pragmaticobjects.oo.tests.Assertion;
+
+/**
+ * Assertion that covers the 3 steps of BDD approach.
+ *
+ * @param <S> The system under test
+ * @param <R> The result of the performed operation
+ *
+ * @author Romain Rochegude
+ */
+public class BehaviorAssertion<S, R> implements Assertion {
+
+    private final Step.Given<S> given;
+    private final Step.When<S, R> when;
+    private final Step.Then<R> then;
+
+    /**
+     * Ctor.
+     *
+     * @param given The Given step
+     * @param when The When step
+     * @param then The Then step
+     */
+    public BehaviorAssertion(
+            final Step.Given<S> given,
+            final Step.When<S, R> when,
+            final Step.Then<R> then
+    ) {
+        this.given = given;
+        this.when = when;
+        this.then = then;
+    }
+
+    @Override
+    public final void check() throws Exception {
+        then.check(
+                when.when(
+                        given.given()
+                )
+        );
+    }
+}
diff --git a/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/Step.java b/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/Step.java
new file mode 100644
index 0000000..d5862af
--- /dev/null
+++ b/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/Step.java
@@ -0,0 +1,52 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+/**
+ * Interface to describe behavior-driven-development steps
+ *
+ * @author Romain Rochegude
+ */
+public interface Step {
+    /**
+     * Interface to describe the Given step.
+     *
+     * @param <S> The system under test
+     */
+    interface Given<S> {
+        /**
+         * Build the system under test instance.
+         *
+         * @return An instance of the system under test
+         */
+        S given();
+    }
+
+    /**
+     * Interface to describe the When step.
+     *
+     * @param <S> The system under test
+     * @param <R> The result of the performed operation
+     */
+    interface When<S, R> {
+        /**
+         * Perform the operation to test.
+         *
+         * @param sut The system under test
+         * @return The result of the performed operation
+         */
+        R when(final S sut);
+    }
+
+    /**
+     * Interface to describe the Then step.
+     *
+     * @param <R> The result of the performed operation
+     */
+    interface Then<R> {
+        /**
+         * Check the result of the performed operation.
+         *
+         * @param result The result of the performed operation
+         */
+        void check(final R result);
+    }
+}
diff --git a/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/package-info.java b/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/package-info.java
new file mode 100644
index 0000000..6023bf1
--- /dev/null
+++ b/tests-core/src/main/java/com/pragmaticobjects/oo/tests/bdd/package-info.java
@@ -0,0 +1,24 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2017 skapral.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.pragmaticobjects.oo.tests.bdd;
diff --git a/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/BehaviorAssertionTest.java b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/BehaviorAssertionTest.java
new file mode 100644
index 0000000..f63dd33
--- /dev/null
+++ b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/BehaviorAssertionTest.java
@@ -0,0 +1,37 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+/**
+ * Test case to validate the {@link BehaviorAssertion}
+ *
+ * @author Romain Rochegude
+ */
+public class BehaviorAssertionTest {
+    @Test
+    public void assertAssertionFailsTest() {
+        assertThatThrownBy(
+                () ->
+                        new BehaviorAssertion<>(
+                                new GivenNop(),
+                                new WhenNop(),
+                                new ThenFails()
+                        ).check()
+        ).isInstanceOf(AssertionError.class);
+    }
+
+    @Test
+    public void assertAssertionPassesTest() {
+        assertThatCode(
+                () ->
+                        new BehaviorAssertion<>(
+                                new GivenNop(),
+                                new WhenNop(),
+                                new ThenSucceeds()
+                        ).check()
+        ).doesNotThrowAnyException();
+    }
+}
\ No newline at end of file
diff --git a/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/GivenNop.java b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/GivenNop.java
new file mode 100644
index 0000000..3f8f30f
--- /dev/null
+++ b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/GivenNop.java
@@ -0,0 +1,13 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+/**
+ * A Given step that does nothing
+ *
+ * @author Romain Rochegude
+ */
+public class GivenNop implements Step.Given<Void> {
+    @Override
+    public final Void given() {
+        return null;
+    }
+}
diff --git a/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/ThenFails.java b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/ThenFails.java
new file mode 100644
index 0000000..4a4b419
--- /dev/null
+++ b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/ThenFails.java
@@ -0,0 +1,15 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+import static org.assertj.core.api.Assertions.fail;
+
+/**
+ * A Then step that fails validation
+ *
+ * @author Romain Rochegude
+ */
+public class ThenFails implements Step.Then<Void> {
+    @Override
+    public final void check(final Void result) {
+        fail("FAIL, just as planned");
+    }
+}
diff --git a/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/ThenSucceeds.java b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/ThenSucceeds.java
new file mode 100644
index 0000000..38ea1a2
--- /dev/null
+++ b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/ThenSucceeds.java
@@ -0,0 +1,12 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+/**
+ * A Then step that succeeds validation.
+ *
+ * @author Romain Rochegude
+ */
+public class ThenSucceeds implements Step.Then<Void> {
+    @Override
+    public final void check(final Void result) {
+    }
+}
diff --git a/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/WhenNop.java b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/WhenNop.java
new file mode 100644
index 0000000..fe4fc71
--- /dev/null
+++ b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/WhenNop.java
@@ -0,0 +1,13 @@
+package com.pragmaticobjects.oo.tests.bdd;
+
+/**
+ * A When step that does nothing
+ *
+ * @author Romain Rochegude
+ */
+public class WhenNop implements Step.When<Void, Void> {
+    @Override
+    public final Void when(final Void sut) {
+        return null;
+    }
+}
diff --git a/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/package-info.java b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/package-info.java
new file mode 100644
index 0000000..dd29c97
--- /dev/null
+++ b/tests-core/src/test/java/com/pragmaticobjects/oo/tests/bdd/package-info.java
@@ -0,0 +1,24 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2017 Kapralov Sergey.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.pragmaticobjects.oo.tests.bdd;