diff --git a/units/en/_toctree.yml b/units/en/_toctree.yml
index 3b6f440..b0d9672 100644
--- a/units/en/_toctree.yml
+++ b/units/en/_toctree.yml
@@ -162,6 +162,14 @@
     title: Conclusion
   - local: unit6/additional-readings
     title: Additional Readings
+- title: Bonus Unit 3. AI vs. AI Challenge, Snowball Fight
+  sections:
+  - local: unitbonus3/introduction
+    title: Introduction
+  - local: unitbonus3/hands-on
+    title: AI vs. AI Challenge Snowball Fight
+  - local: unitbonus3/conclusion
+    title: Conclusion
 - title: What's next? New Units Publishing Schedule
   sections:
   - local: communication/publishing-schedule
diff --git a/units/en/unitbonus3/conclusion.mdx b/units/en/unitbonus3/conclusion.mdx
new file mode 100644
index 0000000..8699fb9
--- /dev/null
+++ b/units/en/unitbonus3/conclusion.mdx
@@ -0,0 +1,11 @@
+# Conclusion
+
+That’s all for today. Congrats on finishing this bonus unit and the tutorial!
+
+The best way to learn is to practice and try stuff. **Why not training another agent with a different configuration?**
+
+And don’t hesitate from time to time to check the [leaderboard](https://huggingface.co/spaces/huggingface-projects/AIvsAI-Snowballfight)
+
+See you on Unit 8 🔥,
+
+## Keep Learning, Stay awesome 🤗
diff --git a/units/en/unitbonus3/hands-on.mdx b/units/en/unitbonus3/hands-on.mdx
new file mode 100644
index 0000000..251b181
--- /dev/null
+++ b/units/en/unitbonus3/hands-on.mdx
@@ -0,0 +1 @@
+# Hands-on 
\ No newline at end of file
diff --git a/units/en/unitbonus3/introduction.mdx b/units/en/unitbonus3/introduction.mdx
new file mode 100644
index 0000000..0118f02
--- /dev/null
+++ b/units/en/unitbonus3/introduction.mdx
@@ -0,0 +1,15 @@
+# Introduction
+
+<img src="https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit11/thumbnail.png" alt="Thumbnail"/>
+
+In the last unit, we trained agents to play soccer. Because this was a 2vs2 mode (with 2 agents per team), we wanted to train cooperative behavior inside the team, which was made possible by MA-POCA (Multi-Agent Posthonomous Credit Assignment) algorithm.
+
+Today, as a bonus unit, we will train agents to learn to play snowball fight.
+
+Snowball Fight is a game made by us with Unity ML-Agents, where you shoot snowballs against a Deep Reinforcement Learning agent.
+
+And by pushing your trained model to the Hub, you’re going to participate in this optional **AI vs. AI challenge** where your trained agent will compete against other classmates’ agents every day and be ranked on a [new leaderboard](https://huggingface.co/spaces/huggingface-projects/AIvsAI-Snowballfight).
+
+<img src="https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit11/snowballtarget.png" alt="Snowballfight"/>
+
+So let's get started,