The electromagnetic scale invariance rule was used to study photonic crystal waveguides in microwave frequencies. This pedagogical approach permits a hands-on ludic experience for students and researchers on a complex subject whose experimental implementation usually demands sophisticated photonic fabrication resources. The microwave approach allows one to construct conceptually equivalent but hand-manipulable prototypes. Square and triangular photonic crystal waveguides, with and without bends, were designed and constructed, and measured and computer-simulated results were compared. © 2011 IEEE.