Smash Up: What Were We Thinking returns to the wild randomness of the early days of Smash Up. By combining this expansion with your Smash Up sets, will you take Zombie Rock Stars against Explorer Dinosaurs? What about Time Travelling Grannies versus Teddy Bear Vampires? It's all possible now! All your dreams can finally come true! Smash Up: What Were We Thinking also marks the release of the 50th faction in this smash-hit line.